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ADA104513 


AFGL TR 80-0365 
JUNfc,. 1980 



REPORT ON RESEARCH 
For the Period July 1976 - December 1978 





Unclassified 


SECURITY CLASSIFICATION of THIS PAGE 'WTimi D«* Entered; 


REPORT DOCUMENTATION PAGE 


READ INSTRUCTIONS 
BEFORE COMPLETING FORM 


» REPORT NUMBER 

A FGX-TR -80-0365 


2. GOVT ACCESSION NO 


. |2. GOV' 


3. RECIPIENT'S CAT ALOG NUMBER 




4. TITLE (and Subtitta) 


Report on "Research , -f- 


Air iorce Geof>hySlC5~Lab 


''' 


s. type of report a period covereo 
Scientific, Interim, 

July 1976-December 1978 ,j 


(. PERFORMING ORG. REPORT NUMBER 

Special Report*,--No. 227 


(& 


?■_ AUTHO WfiJ __„ M 


• ■ CONTRACT OR GRANT NUMBER^ 


John F .j Dempse^Editor 


N/A “ * J “ 

f . V K: 


/' 


y 


». PERFORMING ORGANIZATION NAME AND ADDRESS 

Air Force Geophysics Laboratory 
Hanscom AFB, MA 01731 


10 program element, project, task 

AREA * WORK UNIT NUMBERS 


/6 




, j 9993ft 


XXX 


NIT NUMBERS 


II. controlling office name AND ADDRESS 
Office of the Chief Scientist (CA) 

Air Force Geophysics Laboratory 

Hanscom AFB, MA 01731_ 


flit 


U., BtPi 
Nov 


T T NUMBER OF PAGES 

224 




+ a\ . 


14 MONITORING AGENCY name 4 ADDRE$S(<f dUhtmnt from Controlling OUica) 

/•"' 


IS. SECURITY CLASS, lot Nile 

Unclassified 


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SCHEDULE 

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1*. DISTRIBUTION STATEMENT fol ftlte Report) 

Approved for public release; distribution unlimited. 


17. DISTRIBUTION STATEMENT (ol Ihe etiefrect entered In Block 30, II dlllortnl from Jteporl 


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SEP 2 2 , 


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9 


li SUPPLEMENTARY NOTES 

Tech, other 


19 KEY WORDS (Contlnum on ravatf aida if nacaaamry and Identify by block numbar) 

Geokinetics Solar Radiations Trans-Ionospheric Signal 

Geodesy Balloon Technology Propagation 

Gravity Optical Physics Rocket Instrumentation 

eismology Ionospheric Physics Upper Atmosphere Physics 

j ^Meteorology Magnetospheric Dynamics Upper Atmosphere Chemistry 


ABSTRACT (Contlnum on r«v»ra« aida H nacaaamry mnd identify by block numbar) 

his report continues a series of eight Reports on Research at the Air 
Force Geophysics Laboratory. This report covers a two-and-one-half-year 
interval. It was written primarily for Air Force and DOD managers of 
research and development and more particularly for officials in Headquarters 
Air Force Systems Command, for the Director of Laboratories (DL), and 
for the Commanders of and the Laboratories within DL. It is intended that 
the report will have interest to an even broader audience ., 


DD i jan 73 1473 


Unclassified 


/ 


yi 


SECURITY CLASSIFICATION OF THIS RAGE (Whtn Doit Enltrtd) 




Unclassified _ 

SECURITY CLASSIFICATION OF THIS PAGEfWTien Pete Entered) 

Block 20, continued 

For this latter audience, the report, by means of a survey discussion, 
attempts to relate the programs to the larger scientific field of which 
they are a part. The work of each of the Divisions is discussed as 
a separate chapter. Additionally, the report includes an introductory 
chapter on AFGL management and logistic activities related to the 
reporting period. A listing of the publications of each Division during 
the period follows the chapter describing the research. 


l 


i 


_ Unclassified _ 

SECURITY CLASSIFICATION OF THIS PAGEflWien Pete Entered) 









AFGL-TR-80-0365 


Report 

on 

Research JULY 1976 — DECEMBER 1978 

at 

AFGL 


SURVEYOF 
PROGRAMSAND 
PROGRESS 

THE AIR FORCE GEOPHYSICS 
LABORATORY 

AIR FORCE 

SYSTEMS COMMAND 

HANSCOM AIR FORCE BASE, 

MASSACHUSETTS 


AIR FORCE (1) JULY 25. I960 - 1500 


AUGUST 1980 



Foreword 



The Air Force Geophysics Laboratory 
(AFGL) Report on Research is a continua¬ 
tion of a series published by AFGL's prede¬ 
cessor organization, the Air Force Cam¬ 
bridge Research Laboratories (AFCRL). 
The Air Force redesignated AFCRL to 
AFGL on January 15. 197(5, in order to focus 
attention and effort into geophysics 
research and exploratory development. 

The report reflects the strength and 
breadth of the AFGL scientific program in 
geophysics and its satisfaction of Air Force 
technological and/or system needs for geo¬ 
physics R&D. It is written for DOD 
managers of research and development as 
well as the scientific community. It is a 
biennial report and documents progress and 
on-going programs during the period Juh 
197(5 through December 1978. 



-t 


JAMES F. RAKER 
Colonel, USAF 
Commander 





Contents 


I Ths Air Force Geophysics Laboratory 

C rganization and People .,. Annual Budgets 
. . . Field Sites . . . Research Vehicles . . . 
AFGL Computation Center . . . AFGL Re¬ 
search Library 


II Agronomy Division 

Stratospheric Enrironment . . . Solar I'ltra- 
riotet Radiation . . . Neutral Atmospheric 
Density and Structure... Theoretical Density 
Studies . . . Geopotential Model Studies . . . 
Winter Mesosphere Measurements . . . Satel¬ 
lite Measurements of Composition . . . Lab¬ 
oratory Measurements of Ion Reaction Ki¬ 
netics . . . Chemical-Transport Models 


III Amipac* Instrumentation Division 

Research Rockets . . . Research Satellites . . . 
Free Balloons . . . Low Visibility Measure 
meats . . . Air-Launched Balloons System . . 
In-Flight Balloon Cyogenic Gas Replenish¬ 
ment System . . . Balloon Instrumentation .. 
Project BAMM . . Project STRATCOM 
Atmospheric Sampling Programs . . . 

Pioneer-Venus Drop Tests . . Air Force 

Geophysics Laboratory Scientific Balloon 
Symposiu m 


IV Spsct Physics Division 

The Solar Research Branch . . Defense 

Meteorological Satellite Program . . The 
Energetic Particle Enrironment . . . Solar- 
Terrestrial Enrironment . . . Low Energy 
Plasma and Electric Field Studies . . Space¬ 
craft Charging Technology . The AFGL 
Magnetometer Netnork . . . Ionospheric 
Dynamics . . . Goose Bay Ionospheric Obser- 
rator. . . Signal Scintillations.. . Ionospheric 
Corrections for Precision Radars . . . Solar 
Radio Research. 


V Motsoroiogy Division 115 

Mesoscale Observing and Forecasting 
XfatbCoMputer Internedw Data Access Sys¬ 
tem . . . Weather Radar Techniques . . . Cloud 
Physics . . Weather Erosion Prt)gram . . . 
Atmospheric Modeling . . Climatology . . . 

Weather Modification 


VI Tarrsstrial Sciancss Division 155 

Geodesy and Grarity . . Geokineticr . . . 

Social Studies 


VII Optical Physics Division 175 

Atmosphenc Transmisison . . Infrared 
Rack grounds . . . laboratory Measurements 


Appendices 

A AFQL Projects by Program Element 211 

B AFQL Rocket and Satsiltto Program: 

July 1975 - Dscsmbsr 1979 213 


C AFQL Organization Chart 


215 



AIR FORCE GEOPHYSICS 
LABORATORY 


The Air Force Geophysics Laboratory’ 
came into being on January 15, 197b. by 
redesignation of its predecessor, the Air 
Force Cambridge Research Laboratories. 
This change reflected the Air Force policy of 
naming organizations according to their 
mission, and was made possible when the 
Microwave Physics Division, the Solid State 
Sciences Division, the Electromagnetic 
Environment and Ionospheric Radio 
Physics Branches of the Ionospheric 
Physics Division, and the Laser Physics 
Branch of the Optical Physics Division were 
transferred from AFCRL to the Rome Air 
Development Center, becoming RADC’s 
Detachment 1. the Deputy for Electronic 
Technology. The remaining personnel and 
programs at AFGL are now devoted to 
exploratory and advanced development in 
those areas of geophysics which will meet 
known and anticipated military require¬ 
ments. This report describes the programs, 
activities, and accomplishments of the 
organizations now comprising the Air Force 
Geophysics Laboratory for the period July 
1. 197b, to December 31, 197S. 

AFGL conducts technical programs 
covering a broad spectrum of disciplines in 
the environmental sciences. It is an in-house 
laboratory with a professional staff of 311 
scientists and engineers. Its in-house pro¬ 
grams are augmented by research con¬ 
ducted in universities and industry under 
contracts funded by the Air Force Office of 
Scientific Research (AFOSR). The pro¬ 
grams of AFGL are summarized in the mis¬ 
sion statement: Conducts research, explor¬ 
atory and advanced development in those 
areas of the environmental sciences offering 
the greatest potential to the continued 



superiority of the Air Force's o|>erational 
capability: participates in establishing ad¬ 
vanced technologies whose exploitation will 
lead to new Air Force capabilities. 

Organization and People: AFGL is one 
of 11 laboratories and allied organizations 
under the Director of Science and Tech¬ 
nology. Head(|uarters, Air Force Systems 
Command, at Andrews AFR, Maryland. 
When AFCRL was merged into the Air 
Force Systems Command, the move was 
intended to focus its research and develop¬ 
ment activities more directly on evolving 
Air Force systems, technology, and re¬ 
search requirements. AFCRL’s efforts had 
been coupled with both immediate and long- 
range Air Force needs, and a firm and ex¬ 
tensive data and technology base was 
developed. Continuing pressure on the Air 
Force budget has resulted in a need to 
utilize the available ex|)ertise in solving 
user-command problems, concentrating on 
those areas where technology can have the 
most rapid impact on the o|>erational Air 
Force. 

In the aftermath of the 200-|)osition Re¬ 
duction in Force imposed on June JO, 1D7*>, 
the Laboratory sought to apply the skills of 
those employees transferred to new jMisi- 
tions to new assignments as rapidly as jhis- 
sible. and to direct its most vigorous effoits 
toward serving the needs of those elements 
in the Systems Command which were its 
principal customers. The Space and Missile 
Systems Organization was the largest user 
of AFGL’s technology. 

The six technical Divisions transferred to 
form AFGL in 1070 continued throughout 
this reporting |>eriod. These are the Aeron- 
omy Division, Aerospace Instrumentation 
Division, Meteorology Division, Optical 
Physics Division. Space Physics Division, 
and the Terrestrial Sciences Division. In 
addition, AFGL ojierates a small West 
Coast Office to focus AFGL sup|M»rt to the 
technology requirements and system devel¬ 
opment efforts of the AFSC Space and 
Missile Systems Organization (SAMSO). 
near Los Angeles. 



The AFGl. laboratory complex is locateil IT 
miles west of Boston at Hanscom AKB, 
Massachusetts, when* it is a tenant of AFSCs 
Fleetronic Systems Division. 


The main AFGL laboratory complex is 
located at Hanscom AFR, Bedford. Massa¬ 
chusetts, 20 miles west of Boston. At 
Hanscom AFR, AFGL is a tenant of the 
Electronic Systems Division of the Air 
Force Systems Command. 

Colonel Bernard S. Morgan. Jr., com¬ 
manded AFGL during this entire reporting 
period, having assumed command in 
January 1!*74. Colonel Donald R. Wipper- 
man. w ho had been Vice Commander since 
July '51, 1?*7 5. retired on October 1. 107*1. He 
was succeeded by Colonel Chester G. R. 
Czepvha, w ho came to AFGL from AGMC. 
Col. Czepvha remained as Vice Commander 
through the rest of the report peritxl. 

In December 107S, SI AFGL employees 
held the doctor's degree, trt held master’s 
degrees, and 124, bachelor’s degrees. 
AFGL scientists are active in their resis¬ 
tive professional societies. One scientist 
served as Editor of A/ip/h'd Optics during 
the re|K>rting |>eriod. Another was the 
Alternate l T . S. Delegate to the Solar- 
Terrestrial Physics Group of the Pan- 
American Institute of Geography and 
History. Other AFGL scientists served as 
Associate Editors and referees for various 





3 


professional journals, served on profes¬ 
sional committees, and chaired professional 
meetings and symposia. 

Examples of this type of activity include 
the Chairman of Working Group 4 of the 
Committee on Space Research, Chairman of 
the International Radiation Commission’s 
Working Group on a Standard Radiation 
Atmosphere, and the Commander, who 
served on the editorial boards of the 
Journal of Du mimic Systems, Measure¬ 
ment anil Control, and Com/niters in 
Mathematical Sciences iritli Applications. 

During the 2L> years covered by this Re¬ 
port, AFGL sponsored two, and co¬ 
sponsored one. scientific conferences. 
AFGL scientists and engineers authored 
297 articles in scientific and professional 
journals, presented ‘52*5 pa|>ers at technical 
meetings, and wrote 207 in-house re|>orts. 
These publications and presentations are 
listed at the conclusion of each division 
chapter. 

Annual Budgets: The annual budgets for 
the 2'j years covered in this rejtort are 
shown in the accompanying tables. The 
totals cover salaries, equipment, travel, 
supplies, computer rental, service con¬ 
tracts. and those funds going into contract 
research. The largest e\|*enditure is for 
contract research and equipment. Reflect¬ 
ing the division of AFCRL into AFGL and 
RADC FT in the middle of the fiscal year, 
the budget decreased from <*50 million in FY 
197*5 to <44 million in FY 1977. ft then in¬ 
creased to <*>0.4 million in FY 197s and 
declined slightly, to .<'>0 million in FY 1979. 
This re|M>rting period saw a change in the 
way the money was s|>ent. Although 
salaries had always been the largest single 
item in the past, contract research became 
the largest single item in the budget after 
FY 197*1. The amount fluctuated with the 
budget, decreasing from <25.8 million in FY 
197*5 to .'<22.7 million in FY 1977, increasing 
to <28.5 million in FY 197*. and declining in 
FY 1979 to <27.:5 million. Salaries followed a 


steadier course, changing from approxi¬ 
mately C54 million in FY 197*5 to .<21.7 mil¬ 
lion in FY 1977, to <21.9 million in FY 1978, 
and to <22.7 million in FY 1979. The large 
drop from FY 197*5 to FY 1977 was caused 
bv the separation of RADC7ET from AFGL 
and the Reduction-in-Force completed at 
the end of FY’ 197*5. 

At the same time, the Air Force imple¬ 
mented a policy of having 70 percent of the 
basic research |>erformed by universities, 
and only :50 percent done in-house. Because 
Air Force research needs were perceived as 
changing very much faster than the inter¬ 
ests of any organization with reasonably 
stable employment, this ratio was seen as 
necessary. Over several years of declining 
budgets, this ratio had been reversed to 70 
percent in-house basic research and .'50 
percent University basic research. This 
reversal was the largely accidental response 
to a series of budget cuts as Laboratory 
managers cut where they could while trying 
to keep their organization reasonably 
stable. 

The Air Force Office of Scientific Re¬ 
search was designated the Single Manager 
of all basic research within the Air Force. In 
carrying out this role, AFOSR reviewed all 
pro|>osed basic research, and funded 
selected Laboratory and University proj¬ 
ects. maintaining the 70 - :50 ratio that Air 
Force Headquarters had directed. 

The <28.5 million spent on contract re¬ 
search in FY 1978 was divided among 204 
contracts. Of these, 10*5 were with l T . S. 
universities. 87 with U. S. industrial con¬ 
cerns. The remaining 11 were with foreign 
universities, research foundations, and 
other government agencies. 

AFGL contracts almost always call for 
work in the direct support of the engineer¬ 
ing and development carried out within 
AFGL. They are monitored by scientists 
who are themselves active, participating 
researchers, and who plan the research, 
organize the program, interpret the results, 
and share the workload of the actual re¬ 
search. 


t: 



-I 


Funds received from AFGL's higher 
headquarters, the AFSC Director of Sci¬ 
ence and Technology (DU. and to a lesser 
extent, those received from AFSC organ¬ 
izations other than DL. are used to conduct 
continuing programs. 

AFGL receives support from the Elec¬ 
tronic Systems Division, the host organiza¬ 
tion at Hanscom AFB, in accounting, per¬ 
sonnel, procurement, security, civil engi¬ 
neering, and supply to the laboratory com¬ 
plex. Holloman AFB, New Mexico, pro¬ 
vides services to the AFGL Balloon De¬ 
tachment. AFGL provides support to 
RADC’s Deputy for Electronic Technology 
(FT) in the areas of the Research Library, 
laboratory materials needed for the ET 
mission, computer, technical photography, 
mechanical and electrical engineering of 
laboratory layouts, electronic 

instrumentation, and woodworking. 



More than half of the tils AFGL personnel are 
scientists or en>rineers. Of these. SO have 
received the Ph.I). decree. 

Field Sites: In addition to the buildings 
which it occupies at Hanscom AFB, AFGL 
operates several off-base sites, locally and 
at distant locations. The largest local site is 



The AFGL Weather Radar Facility, at 
Sudbury. Massachusetts, is one of the larger 
off-base sites. It is used to study possible new 
ways to derive meteorological information 
from radar observations. 

the Sagamore Hill Radio Observatory at 
Hamilton. Massachusetts, which has an S4- 
foot radio telescope and several smaller 
telescopes. Other local sites are the 
Weather Radar Research Facility at Sud¬ 
bury. Massachusetts, and the Weather Test 
Facility at Otis AFB. Massachusetts. 

AFGL operates a balloon launch site at 
Holloman AFB. New Mexico. AFGL also 
maintains a seven-man branch of the Solar 
Physics Division at the Sacramento Peak 
Solar Observatory, at Sunspot, New 
Mexico. AFGL had operated the Observa¬ 
tory approximately 2o years, but ownership 
was transferred to the National Science 
Foundation on June HO. 107ii. 

One very remote station is the Goose Bay 
Ionospheric Observatory at Goose Bay Air 
Station. Labrador, where studies of a 
variety of subarctic events are made, in¬ 
cluding polar cap absorption of high fre¬ 
quency radio waves. 

AFGL field programs utilize a number of 
military installations including the Fort 
Churchill, Canada, rocket range: Fort 





Wainwright and Eielson AFB. Alaska: 
Albrooke AFB, ('anal Zone; Travis AFB, 
California: Vandenberg AFB. California: 
and the White Sands Missile Range. New 
Mexico. In addition to these military sites. 
AFGL has used other locations on a tem¬ 
porary basis. Commercial air|M>rts and the 
Poker Flat. Alaska, range are also used. 

Research Vehicles: From its jiemianent 
balloon launch site at Holloman AFB, New 
Mexico, and from temporary sites in several 
other locations, AFGL launched 14(> large 
research balloons during the 2 1 - year 
period. Of these. 14 were launched during 
FY 7T, i»N during FY 77 and .77 during FY 
7 s . In addition, 22 tethered flights were con¬ 
ducted. These balloons carried test and 
experimental payloads for the Space and 
Missile Systems Organization (SAMSO). 
the Defense Nuclear Agency (DNA>. the 
National Aeronautics and Space Admini¬ 
stration. the Energy Research and Devel¬ 
opment Administration (now the Depart¬ 
ment of Energy), the Army, and university 
scientists with military contracts. AFGL 
scientists themselves are. however, the 
largest users. 

Rockets are used to examine almost 
every as|K*ct of the earth's up|>er atmos¬ 
phere and near-space environment — 
winds. teni|>eratures and densities: the 
electrical structure of the ionosphere: solar 
ultraviolet radiation; atmospheric com|>osi- 
tion: the earth's radiation belts; cosmic ray 
activity, and airglow and aurora. The 
rockets most frequently used have been the 
Aerohee and combinations using the Nike 
booster, such as the Nike-Hydac. 

During the past 2‘j years, a total of 2s 
large research rockets were launched. The 
White Sands Missile Range was used most 
often (12 launches). Others were launched 
from Poker Flat Rocket Range, Alaska (7); 


Kwajalein Missile Range (5): Wallops 
Island, Virginia (2): and Fort Churchill, 
Canada (2). 

During this reporting period, packages 
designed here were carried aboard two Air 
Force scientific satellites, the NASA At¬ 
mosphere Explorer D and E satellites, and 
the SOLRAD satellites. 

AFGL Computation Center: AFGL 
operates a large scientific data processing 
facility consisting of two CDC (MX) comput¬ 
ing systems which sup|>ort AFGL, ESD, 
other government agencies and DOD con¬ 
tractors. 

The CDC (>(>00 systems consist of a 
modular desugned multi-processor oper¬ 
ation with extensive input-output devices, 
peripheral equipment and communications 
equipment. The systems provide remote 
batch, interactive graphics and conversa¬ 
tional capabilities through a network of 
approximately TO remote stations located 
within the laboratory complex and at off- 
base locations. The de-commutation facility 
processes data from satellites, rockets, 
aircraft, balloons and from laboratory data 
collection systems, using two sjiecial pur¬ 
pose Honeywell computer systems. 

AFGL Research Library: The breadth 
and quality of the technical collection main¬ 
tained by the AFGL Research Library are 
surpassed bv few libraries in the country. 
Available to AFGL scientists are the scien 
tific journals of Bulgaria, Czechoslovakia, 
vhe Netherlands. France. Germany. 
Hungary. Italy. Japan. Poland. Russia and 
Sweden. The collection of Chinese science 
journals and monographs is one of the most 
comprehensive in the V. S. Associated with 
the foreign |>eriodical collection are 
translation services. 





TABLES 

SOURCES OF FY-1977 FUNDS 


Air Force Syatems Command - DL 

Air Force Systems Command • Other than DL 

Defense Nuclear Agency 

Defense Mapping Agency 

Army 

Energy Research and Development Command 
National Aeronautics and Space Administration 
Air Weather Service 
National Security Agency 
Navy 

Other Air Force 


$23,540, 

15,569, 

2,391, 

962, 

941, 

565, 

163, 

85, 


TOTAL 


$44,365,1 










7 


TABLE 4 

SOURCES OF FY-1978 FUNDS 


Air Force Systems Command - DL 

$27,359,000 

Air Force Systems Command - Other than DL 

18,470,000 

Defense Nuclear Agency 

2,250,000 

Army 

898,000 

Defense Mapping Agency 

686.000 

Energy Research and Development Administration 

6»A«C0 

Air Weather Service 

8. »M) 

National Security Agency 

50,000 

National Aeronautics and Space Administration 

35,000 

Navy 

20,000 

TOTAL 

$50,439,000 


TABLE 5 

SOURCES OF FY-1979 FUNDS 


Air Force Systems Command - DL 

$26,222,000 

Air Force Systems Command - Other than DL 

19,546,000 

Defense Nuclear Agency 

2,702,000 

Defense Mapping Agency 

775,000 

Department of Energy 

367,000 

Army 

244,000 

Air Weather Service 

101,000 

Air Defense Command 

53,000 

National Aeronautics and Space Administration 

27,000 

Air Force Communications Service 

9,000 

TOTAL 

$50,046,000 






BEAM CONTROL 
ORIFICE 


BIASED 

CONE 


COLD PUNK 
CYLINDER 


RADIATION 

SHIELD 


OUADRUPOLE 

PREFOCUS 

ASSEMBLY 


RADIATION 

SHIELD 

CHEVRONS 


OUADRUPOLE 
MASS FILTER 


/ LIQUID HELIUM 
/ FILL PORT 


VACUUM 

EXHAUST 

VALVE 


liquid helium 
RESERVOIR 


LIQUID HELIUM 
VAPOR EXHAUST 


EM CATHODE <**SOOV 
!NEGATIVE ION TARGET) 


POSITIVE ION 
TARGET «l -SkV 


DETECTION 

ELECTRONICS 


ZEOLITE 

ABSORPTION 

ai iDttrr 

SURFACE 


D region positive/negative ion mass spectro¬ 
meter. 





II AERONOMY DIVISION 



< 



y 


S 


* 

| 

1 


r 


Aeronomy is the study of the physical and 
chemical properties of the earth’s upper 
atmosphere. It deals principally with the 
atomic, molecular, and ionic composition of 
the atmosphere and how the composition is 
influenced by energy sources such as solar 
radiation. The Aeronomy Division’s prin¬ 
cipal investigations are in the altitude re¬ 
gions above about 15 km, which include the 
stratosphere, mesosphere, and thermo¬ 
sphere. 

The study of the stratospheric environ¬ 
ment is a major activity of the Division. The 
National Environmental Policy Act of 1969 
requires the Air Force to provide envi¬ 
ronmental impact statements for the opera¬ 
tion of aircraft such as the F-16 fleet. Ques¬ 
tions which must be answered include: 
What will aircraft emissions do to the ozone 
content of the stratosphere? How will this 
affect the environment on earth, which in¬ 
fluences agriculture and marine life? To 
answer questions such as these, the Divi¬ 
sion is engaged in a cooperative program 
with other government agencies such as 
Army, Navy, National Aeronautics and 
Space Administration, National Oceanic 
and Atmospheric Administration, Depart¬ 
ment of Energy, Environmental Protection 
Agency, National Science Foundation, and 
the Department of Transportation. The 
Division performs stratospheric exper¬ 
iments primarily by using high-altitude bal¬ 
loons to determine trace-gas, ion, and aero¬ 
sol composition of the stratosphere with 
special emphasis on those constituents that 
react chemically with stratospheric ozone. 





to 


The solar ultraviolet radiation incident on 
top of the stratosphere and its absorption 
within the stratosphere by ozone and other 
trace constituents are measured by means 
of spectrometers flown on balloons and 
rockets. Stratospheric winds, temperature, 
and turbulence are being measured with 
balloons and sounding rockets to develop 
models for predicting the dispersion, 
spreading, and lifetime of aircraft and mis¬ 
sile exhaust products in the stratosphere. 
The effects of engine emissions and aircraft 
venting of unbumed fuel on the envi¬ 
ronment are also assessed. Laboratory 
experiments are conducted to measure 
parameters and reactions of important 
stratospheric molecules. Models for waves 
and turbulence in the stratosphere are 
developed for determining the environ¬ 
mental effects of Air Force operations. 

The measurement of ultraviolet radiation 
is another major effort in the Division. Ul¬ 
traviolet radiation from the sun is the prin¬ 
cipal source of energy for the earth’s upper 
atmosphere and has a dominating influence 
on atmospheric composition, density, and 
ionization. Atmospheric background radia¬ 
tion in the ultraviolet region of the spectrum 
limits the detection capability of ultraviolet 
surveillance systems. Also, ultraviolet 
radiation emanating from the earth’s 
horizon has the potential of providing im¬ 
proved horizon sensors for satellite naviga¬ 
tion systems. These sources of ultraviolet 
radiation are measured with optical spec¬ 
trometers flown on rockets and satellites. 

Another major area is the development of 
improved models of the properties of the 
earth’s upper atmosphere. The Division has 
had a major role in the development of U.S. 
Standard Atmosphere, 1976, a cooperative 
effort involving the Air Force, the National 
and Space Administration, and the National 
Oceanic and Atmospheric Administration. 
In systems operations, the Division is work¬ 
ing on atmospheric density models and on 
geopotential models for the Aerospace 
Defense Command to be used in its tracking 
operations of all space objects. The atmos¬ 



Ionospheric structure and composition of the 
nighttime equatorial E and lower F regions. 


pheric data necessary for the development 
of these models are obtained from mass 
spectrometers, ionization gauges and accel¬ 
erometers flown on rockets and satellites. 
Neutral atmospheric density and tempera¬ 
ture are also obtained by falling spheres 
launched in rockets. A parallel laboratory 
effort in theoretical density studies, atmos¬ 
pheric modeling, and measurements of ion- 
neutral reaction rates has improved the 
understanding of the chemical processes 
occurring in the upper atmosphere. 

Another major area is the study of dis¬ 
turbed atmospheres. Systems operating in 
or through the earth’s upper atmosphere 
may be affected by both natural distur¬ 
bances such as polar cap absorption events, 
auroral events, and sudden ionospheric dis¬ 
turbances, and by atmospheric nuclear 
detonations. The Division, in cooperation 
with the Defense Nuclear Agency, is 
measuring atmospheric properties during 
natural disturbances and developing models 
which are used as inputs to computer codes 
for predicting the atmospheric effects to be 
expected from nuclear detonations. Among 
the properties measured are the ion and 
neutral composition of the upper atmos¬ 
phere and equatorial ionospheric irregu¬ 
larities. The studies are accomplished with 
mass spectrometers flown in sounding 
rockets to probe the D and E regions of the 





11 


ionosphere. In addition, laboratory exper¬ 
iments are performed to study chemical 
reactions that may also occur in the upper 
atmosphere such as the study of thermo¬ 
chemical properties of metal oxides and 
reactions between atmospheric ions and 
molecules. 

The Division’s investigations are per¬ 
formed by means of theoretical studies, 
laboratory experiments and experiments by 
means of aircraft, balloons, sounding 
rockets and satellites. The satellite exper¬ 
iments are performed both on Air Force 
satellites and on satellites of the National 
Aeronautics and Space Administration 
(NASA). The Division is supporting the 
Defense Meteorological Satellite Program. 
The Division has experiments on the NASA 
Atmosphere Explorer satellites. It recently 
has had a successful experiment on an Air 
Force-STP satellite to measure ultraviolet 
background radiation. Proposals for future 
experiments for SPACE LAB have been 
submitted. One of these experiments pro¬ 
posed will use a laser beam to probe the 
earth’s atmosphere down to the strato¬ 
sphere to determine atmospheric densities 
on a global basis. Two other proposed ex¬ 
periments will measure global background 
radiation in the ultraviolet and the long¬ 
term variations of solar ultraviolet radia¬ 
tion. 

STRATOSPHERIC ENVIRONMENT 

Interest and concern has been focused on 
the stratosphere during the last few years 
because it is becoming evident that man’s 
activities can significantly change the en¬ 
vironment. Banning of chlorofluoromethanes 
in aerosol sprays has been suggested, be¬ 
cause they may contribute to the destruc¬ 
tion of the ozone layer in the stratosphere. 
Some Air Force weapons systems operate 
in the stratosphere, and careful evaluations 
must be made to avoid inadvertent modi¬ 
fication of the environment. 

The stratosphere is commonly defined as 
that part of the lower atmosphere where the 



Forward end of D region ion mass spectro¬ 
meter payload showing the conical sampler. 

Th» ambient ions enter through a 0.030 inch 
diameter hole at the cone’s apex. 

temperature increases with altitude, 
typically extending from 12 to 50 km. Ozone 
is a minor constituent of the stratosphere, 
but it is directly important to man because it 
absorbs harmful solar radiation. Although 
its concentration is only a few parts per 
million, ozone is the only atmospheric con¬ 
stituent which can absorb solar radiation 
between 200 and 300 nanometers. The in¬ 
crease of temperature with altitude in the 
stratosphere creates a very stable region, 
which does not have any obvious exits for 
gaseous pollutants. Pollution remains in the 
stratosphere for years, all the time chem¬ 
ically reacting to reduce the ozone con¬ 
centration. Thus, even small amounts ol 
pollution can have a large effect on the ozone 
concentration. 






12 


< 


4 


I 

2 


The stratospheric environment program 
has the important task of predicting what 
environmental changes can occur from 
USAF missile and aircraft operations in the 
stratosphere. In this program, minor strat¬ 
ospheric constituents, aerosols, solar en¬ 
ergy deposition, and pollution transport 
properties and residence times in the strat¬ 
osphere are measured. These measure¬ 
ments are made with unique, state-of-the- 
art instruments flown on large balloon 
systems. Mathematical models are con¬ 
tinually revised by incorporation of the 
newest determinations of reaction rate con¬ 
stants and data on density. A respected 
scientific technology base and predictive 
models exist to determine if changes occur 
in the atmosphere as a result of emissions 
from USAF flight operations. This cap¬ 
ability has been used to provide environ¬ 
mental assessments on aircraft and missile 
systems. 

Whole-Air Sampling Measurements: 

The primary method for measuring the 
composition of the stratosphere is to fly a 
cryogenic vessel on a high-altitude balloon, 
collect a one-mole sample, and return it to 
the laboratory for trace gas analysis. Cryo¬ 
genic sampling provides large sample 
quantities and minimum potential for 
chemical changes in the stored sample. The 
first liquid helium cooled sampler used in 
this program collected a single one-mole 
sample on each flight. A newer tri-sampler 
collects a one-mole sample at each of three 
altitudes on each flight, providing both more 
economical operation and same-day meas¬ 
urements of a large altitude range. 

Three sample holders are immersed in a 
single liquid helium chamber which is 
thermally shielded by both liquid nitrogen 
and vacuum blankets. The sampling valves 
are remotely actuated in sequence. The air 
sample tubes are sized for the altitude at 
which they are used so that the air mole¬ 
cules enter slowly enough to freeze on their 
first contact with the cylinder wall. Samples 


are taken only while the balloon is descend¬ 
ing, and a fan downstream from the 
sampling tube draws air across the sample 
tube inlet from a larger diameter tube which 
extends 6 meters below the gondola. These 
precautions prevent contamination of the 
samples by the flight package. 

The original gondola is approximately 
spherical, with a flat base and a low center of 
gravity, so that it is self-righting. A second 
gondola was designed to be compact, rug¬ 
ged, and aerodynamically stable, for use 
w'hen air snatch of the package is necessary. 

Nine flights, all successful, were con¬ 
ducted during the reporting period. Sam¬ 
ples were obtained at five latitudes, and six 
altitudes: 12, 15, 18, 20, 25, and HO km. The 
flights from Alaska and Panama were air 
snatched, while those from California, New 
Mexico, and South Dakota were recovered 
from the ground. 

Nitric oxide and nitrogen dioxide concen¬ 
trations are measured with two chemi¬ 
luminescence analyzers with different de¬ 
signs measuring different emission wave¬ 
lengths. In this way, concentrations in the 
low parts per billion range are measured 
more accurately and spurious signals from 
other chemiluminescent reactions are kept 
to a minimum. Nitric oxide and nitrogen 
dioxide concentrations measured are higher 
than those obtained in most other exper¬ 
iments, do not vary markedly with latitude, 
and exhibit an altitude profile similar to the 
June 1978 Alaska results. 

The other chemical species of interest are 
analyzed with a gas chromatograph. The 
present instrument uses a custom injection 
system, nitrogen carrier gas, and an elec¬ 
tron capture detector to achieve stronger 
and better resolution of early eluting trace 
gas peaks, permitting measurements down 
to the low parts per trillion range. Concen¬ 
trations of nitrous oxide were found to drop 
off from the troposphere value of 320 parts 
per billion to approximately 100 parts per 
billion at 80 km near the equator. The de¬ 
crease was greater at higher latitudes. 
Fluorocarbons 11 and 12 were measured in 



13 


the pails per trillion range and exhibit 
variations with altitude and latitude similar 
to that for nitrous oxide. 

Any changes with time of any of these 
concentrations will provide input for pos¬ 
sible correlations with increased Air Force 
operations in the stratosphere. 

Mass Spectrometer Measurements: To 

complement whole air sampling measure¬ 
ments, preparations are being made to 
sample both positive and negative ions in 
the stratosphere with a balloon-borne quad- 
rupole mass spectrometer. It has been sug¬ 
gested that a balloon gondola could charge 
to a high potential, adversely affecting the 
measurement accuracy. To see if this prob¬ 
lem is real, the potential to which a balloon 
gondola charges in the stratosphere was 
measured. 

The charge on the gondola was deter¬ 
mined by measuring the potential difference 
between a small sphere held extended from 
the gondola and the gondola itself. The 
sphere has a small radius so that a large 
electric field would result from a small 
potential, and thus tend to remain close to 
the plasma potential. The sphere was plat¬ 
inum plated to reduce photoemission. 

The first measurements detected a po¬ 
tential of only a few volts. Further meas¬ 
urements are scheduled. 

A switched positive and negative ion 
mass spectrometer has been developed and 
is being prepared for measurements start¬ 
ing in 1980. The results will be used to 
evaluate ion chemistry in the stratosphere 
and its interaction with pollutants. 

Stratospheric Aerosols: Trapping 
stratospheric aerosols and returning them 
to the laboratory for analysis is the method 
which has been used up till now. Howeer, 
chemical changes, such as the evaporation 
of volatile constituents, can occur in the 
time between capture and analysis. A new 
aerosol composition instrument being 
developed will avoid this problem by vapor¬ 
izing the particle with a laser pulse and then 



Recovered DMSP/SSD mass spectrometer 
payload showing the gas accommodation 
sphere. 


identify the vaporized fractions optically. 
The first flight of this new instrument is 
planned for 1982. 

Wave and Turbulence Models: Tur¬ 
bulence is one mechanism by which strato¬ 
spheric constituents are mixed and pollution 
transported out of the stratosphere. The 
contribution of turbulence to pollution 
transport is now known. However, the ex¬ 
tent ofsmixing is an important factor in the 
determination of the stratospheric chem¬ 
istry. 

During this reporting period, we have 
studied the assumptions made by other in¬ 
vestigators. Measurements of turbulence 
were made by a U-2 flying in the 20 km 
height range. When the power spectrum of 
the wind fluctuations was determined, it 
seemed to be the “Kolmogorov inertial 
range spectrum," which is the typical spec¬ 
trum of turbulence. However, the wave¬ 
lengths extended to lengths much too long 
to be turbulence. We found that these spec¬ 
tra can be explained if the long wavelength 
components are gravity waves due to buoy¬ 
ancy effects. Tests will be performed soon. 
If they validate this theory, then previous 
estimates of turbulence transport may have 
to be completely revised. 




14 


Theoretical work on an AFGL-developed 
turbulent transport model is a second effort 
in this area. The model has proven useful 
since it seems to be the only model for ver¬ 
tical stratospheric turbulent transport 
which uses vertical profiles of the horizontal 
winds obtained by rocket trial data or by 
radar data on atmospheric reflections. 

Turbulence Measurements: Several 
measurement techniques are being used to 
define the |>ersistence. altitude distribution, 
latitudinal variation and seasonal variation 
of stratospheric turbulence. The altitude 
distribution is measured by analysis of ver¬ 
tical smoke trails deposited by rockets. 
Time lapse photographs of the smoke trails 
are analyzed to an altitude resolution of 10 
meters. This |»ermits identification of the 
pancake-like turbulence layers, several 
hundred meters in thickness. The smoke 
trails are de|x>sited at twilight bv release of 
a titanium tetrachloride-water-methanol 
mixture which produces dense chemical 
smoke from an altitude of about 15 km to 
rocket apogee. In a series of experiments in 
1070-77, the rocket ajwgee was near 25 km. 
A more comprehensive program was begun 
in 197M in which the a|>ogee was near 55 km. 
The new program will investigate the varia¬ 
tions in stratospheric winds, wind shears 
and turbulence with latitude. In 197S, two 
rockets were flown from Wallops Island, 
Virginia (latitude 38 degrees N) and Fort 
Churchill, Canada (latitude 58 degrees N). 
This program will be finished in 1979 with a 
series of rocket launches scheduled at Lima, 
Peru. They will provide the data for equa¬ 
torial latitudes. Measurements of temj>era- 
ture, nearly simultaneous with the rocket 
launches, will be combined with computed 
wind shears to determine profiles of Rich¬ 
ardson’s number as a function of altitude. 

A second method of measuring turbu¬ 
lence is to use a turbulence sensor mounted 
on a balloon. The balloon sensor can float in a 
turbulence layer for long periods of time to 
record the lifetime of the turbulence layer. 
The instrument, developed specifically for 


stratospheric measurements, senses the 
deflection of a transverse corona ion beam 
caused by the wind and turbulence. The 
velocity and velocity fluctuations are 
measured and analyzed to obtain altitude 
profiles of the wind shear and Fourier 
spectra of the fluctuations to identify the 
turbulence. A series of flights from Hollo¬ 
man AFB, New Mexico, measured turbu¬ 
lence in the vicinity of mountains. Similar 
flights from Watertown, South Dakota, 
measured turbulence over the Great Plains. 
Analysis of the wind shears and turbulence 
spectrum determines the eddy diffusion 
coefficient of the stratosphere with and 
without mountain effects. 

Radar observations of scattering layers 
at altitudes up to 20 km provide one means 
of observing turbulence over long periods of 
time. Data from the Millstone radar were 
analyzed with simultaneous radiosonde data 
to provide estimates of the eddy dissipation 
rate and the eddy heat diffusion coefficient. 
The median eddy diffusion coefficient be¬ 
tween 13 and 16 km altitude did not change 
from season to season. 

Rawinsonde data taken at 144 stations 
between 1970 and 1976 for altitudes of 0-30 
km, and rocketsonde data taken at 10 sta¬ 
tions between 1969 and 1975 for altitudes for 
20-55 km were acquired on magnetic tape 
from NOAA. Smooth curves were fitted to 
the temperature and wind observations, 
and the Richardson number, a criterion for 
the onset of turbulence, was obtained at 1 
km intervals. Where the Richardson num¬ 
ber indicated turbulence, an empirical 
formula was used to obtain the turbulent 
intensity, the dissipation of kinetic energy, 
and the turbulent diffusivity. Levels with 
pronounced occurrence of turbulence are 
found in the troposphere. The levels vary 
with season and latitude. Global models of 
turbulence as a function of season, latitude, 
and altitude are being developed for use in 
the troposphere and stratosphere. 

Solar Ultravioiat M —a ura m a nta : Solar 
ultraviolet radiations at wavelengths from 
200-310 nm were measured at altitudes up 


i 

f 




15 


to 40 km on four balloon flights. A grating 
spectrometer with a wavelength resolution 
of 0.012 nm obtained data of excellent qual¬ 
ity on the 8-hour flights. Solar radiation in¬ 
tensities and ozone concentrations are being 
determined from these measurements. 

Ozone Photodissociation: Relatively 
little is known about the state of the ozone 
molecule after it absorbs ultraviolet radia¬ 
tion. The bond strength and geometric 
structure for the upper electronic state of 
the molecule are unknown. They are impor¬ 
tant for understanding ozone destruction 
processes. An indication of the bond 
strength is given by the potential well 
depth. The potential well depth, in turn, can 
be inferred from the location of the band of 
absorption caused by the lowest energy 
transition from the ground state to the up¬ 
per electronic state. For over 80 years, the 
band at 851.8 nm was assumed to be this 
band. However, isotope shift analysis and 
the observation of previously unreported 
bands for cooled ozone, show that this trans¬ 
ition should give rise to a band at 868.6 nm. 
This results in a potential well depth for the 
upper electronic state which is 1828 cm 1 
deeper than previously assumed. Studies to 
deduce the geometrical structure are now in 
progress. 

Environmental Assessments of Engine 
Emissions: The jwssible damage to the 
stratospheric ozone was assessed for the F- 
16 fleet, the KC-10A tanker fleet and the 
High Altitude High Speed Target. It was 
found that F’-16 and KC-10A operations 
would have no measurable effect on strato¬ 
spheric ozone. The computations indicated 
that the ozone should increase slightly, in 
line with recent developments in strato¬ 
spheric chemistry which indicate that an in¬ 
jection of nitrogen dioxide below 25 km will 
cause an increase in ozone. 

Nitrogen dioxide and hydrogen fluoride 
are the only effluents of concern from the 
High Altitude, High Speed Target. Because 
a small number of flights are contemplated, 



Sunrise D and lower E region electron densi¬ 
ties predicted theoretically compared to 
measurement by Langmuir probes. The x 
angles for the measurements and theory are 
given in the figure. 

the concentrations of the effluents will be 
much below ambient. No environmental 
damage is anticipated from these flights. 

Aircraft Venting of Unbumed Fuel: En¬ 
vironmentalists are concerned about pos¬ 
sible changes in atmospheric composition or 
damage to crops from the occasional jettison 
of unburned fuel. In an experimental pro¬ 
gram, a sampling aircraft flew directly 
through a fuel dump at selected altitudes to 
measure fuel drop size and number dis¬ 
tributions. 

The measurement results of the 
sampling, fuel dump wake size and 
hydrocarbon vapor content were analyzed 
and a multi-component fuel drop model was 
used to predict the amount of drop vaporiza¬ 
tion and determine the initial drop size and 
number distribution. The observed drop 
size distribution was corrected for evapora¬ 
tion using the model to estimate the initial 
droplet formation size. For the KC-185 air¬ 
craft fuel venting procedures, the median 
drop diameter formed is 270 /xm. It was 
determined that fuel jettisoned 5,000 feet or 
higher will evaporate before reaching the 
ground. Ground contamination can be 
avoided, eliminating any potential environ¬ 
mental damage. 



(6 


UPPER ATMOSPHERE COMPOSITION 

The local detailed chemistry of the upper 
atmosphere determines the electron distri¬ 
bution in this region. The electron distribu¬ 
tion, in turn, affects radio waves, radar, and 
satellite signals. The Air Force needs to 
know the chemistry of the normal and dis¬ 
turbed upper atmosphere. It also needs to 
know the effects of nuclear detonations on 
the upper atmosphere. 

Equatorial Ionospheric Irregularities: 

The Defense Nulcear Agency conducted 
rocket and ground-based programs at 
Kwajalein during Augut 1977 and 1978 to 
examine radio communications. Rockets, 
and ionosonde, and radar measured the 
ionosphere simultaneously, while signals 
from the DNA WIDE BAND satellite were 
measured. A Talos-Sergeant-H.vdae rocket 
carrying an ionospheric diagnostic payload 
was launched near midnight on August 2d, 
1977, attaining an apogee of 161 km. The 
AFGL-supplied mass spectrometer ob¬ 
tained excellent measurements between 78 
and 1*11 km. The results showed a s|>oradic 
E layer near 109 km composed of meteoric 
ions with silicon ions dominant, as well as 
higher altitude layers composed mainly of 
nitric oxide ions. From this layer structure, 
wind patterns and motions which may 
initiate ionospheric instabilities may be 
deduced. 

Two similar rockets were launched from 
Kwajalein on August 8 and August Id. 1978, 
both with apogees of about 2d0 km. Meas¬ 
urements between 100 and 2d0 km showed 
that the ionospheric E and lower F regions 
were typical of quiescent conditions, and 
consisted of nitric oxide ions, along with 
about 10 jiercent ox\gen ions. The F-region 
ledge com(M)sed of atomic oxygen ions was 
apparent near ajKigee. These results have 
defined the ionospheric structure near the 
lower boundary of the F-region instability. 

In another effort, quadrupole ion mass 
s|>ectrometers have been designed and 
constructed to study ionospheric irregu- 



Nitrie oxide profiles inferred from analysis of 
eight ionic composition profiles using the mean 
CIRA 1972 atmosphere. 


larities from the space shuttle. Plans call for 
these instruments to be boom-mounted on 
the shuttle. In the future they will also be 
included on the Low Altitude Satellite 
Studies of Ionospheric Irregularities 
(LASSII) satellite, which will be launched 
and retrieved by the space shuttle. These 
efforts are joint agency programs involving 
principally the Air Force Geophysics 
Laboratory and the Naval Research 
Laboratory. 

D-R«glon Ion Moss Spoct r omotw 

DovtJopmont: A new rocketbome mass 
spectrometer system was designed, built, 
tested and flown for measurements of posi¬ 
tive and negative ions in the D and sub-D 
regions (from about 35 km up). The instru¬ 
ment consists of a double quadrupole mass 
spectrometer housed in a liquid helium cryo- 
pump. Its unique feature is a conical sam¬ 
pling structure designed to attach and 
swallow the shock wave in order to avoid 
thermodynamic breakup of the large posi¬ 
tive and negative cluster ions observed in 
the D region. The spectrometer configura¬ 
tion has undergone extensive wind tunnel 





17 


r 1 




) 

I 



tests to insure that the shock wave is 
attached. An engineering test payload con¬ 
taining this instrument and two Gerdien 
Condensers to measure positive and nega¬ 
tive ion mobilities and densities was 
launched on a Nike Tomahawk from White 
Sands, New Mexico, at 1500 MDT on Sep¬ 
tember 15, 1978. Measurements were ob¬ 
tained between 48 km and apogee, which 
was at 114 km. A number of instrumental 
parameters were varied to examine ion 
sensitivity and mass resolution as well as 
cluster ion breakup as a function of the ion 
draw-in electric field. Cluster ions were 
observed below 82 km giving way to nitric 
oxide and oxygen ions above this altitude. 
Meteoric ions of sodium, magnesium, alumi¬ 
num and iron were also found in a broad 
layer near 9.1 km. Breakup of the large clus¬ 
ter ions was observed when the ion draw-in 
electric field was increased, and instru¬ 
mental sensitivity and resolution param¬ 
eters were determined. It is planned to con¬ 
duct several measurement programs with 
these instruments, including a total solar 
eclipse and solar proton events. These 
measurements are required to develop D- 
region models for both natural and nuclear 
disturbances to determine and predict the 
effects on systems using VLF, LF and HF 
propagation. 


OMSP Supplementary Sensor Density 
Calibration: A neutral mass spectrometer 
was designed, built and flown on a rocket to 
measure composition and density between 
120 and 200 km. This instrument will be 
used in a joint AFGL program to calibrate 
the supplementary density instrument on 
board the DMSP satellites for the purpose 
of obtaining real-time satellite drag. The 
mass spectrometer uses a spherical gas 
accommodation sampling geometry. The 
gas is thermalized in the sphere before be¬ 
ing analyzed by a quadrupole mass spec¬ 
trometer. In this manner, the inside pres¬ 
sure can be related to the ambient accu¬ 
rately. 


The payload, after launch, performs a 90- 
degree yaw maneuver and cartwheels along 
the trajectory, spinning the mass spectro¬ 
meter orifice in and out of ram. This is done 
to determine the rocket outgassing back¬ 
ground, which is a significant signal, espe¬ 
cially for nitrogen. Nitrogen, argon, helium 
and oxygen concentrations are measured. 
This payload was successfully test flown on 
September 15, 1977 from the White Sands 
Missile Range, obtaining measurements be¬ 
tween 110 and 200 km. 

Nitric Oxide: Auroral and Quiet E- 
Region: A rocket-borne mass spectrometer 
launched from Poker Flat, Alaska, on 
March 27, 197.1. at about midnight was suc¬ 
cessful in measuring the ion composition 
within an auroral arc. Analysis of the data 
showed good agreement with a model using 
laboratory rate constants if the nitric oxide 
concentration was allowed to reach 10” cm 1 
near 105 km. this concentration being about 
ten times the normal amount expected. 

Subsequently, the ion composition pro¬ 
files of all eight published auroral flights 
were compared with an auroral ion com¬ 
position model. Five of these eight flights 
were bv AFGL. Although no clear pattern 





Nitric oxide distributions determined from ion 
composition experiments for the indicated 
latitudes, dates, sunspot numbers, and solar 
zenith angles. 


I 





was discernible from the NO' 0. ion ratio 
for the eight flights, comparison of the data 
with the model showed that the neutral 
nitric oxide profiles of the auroral E-region 
ranged from normal to enhancements of an 
order of magnitude above normal. This de¬ 
duction is in general agreement with nitric 
oxide gamma-band satellite information by 
others. On the other hand, our results 
essentially refute information by one group 
which suggested that nitric oxide could 
attain concentrations at least as large as 10" 
cm 1 in the E region. 

Nitric oxide profiles were deduced re¬ 
cently from all ten of the available ion com¬ 
position data sets available for the non- 
auroral daytime E-region. Excluding the 
three high-latitude winter profiles, the 
nitric oxide profiles obtained are generally 
in good accord with concentrations deter¬ 
mined from gamma-band measurements of 
nitric oxide radiation. Within a factor of d, 
nitric oxide concentrations were found to 
vary from 1 x 10* cm ! at 100 km to 2 x 10“ 
cm ; at So km for various sunspot numbers 
and seasons, except winter. This strong 
gradient suggests a vertical eddy diffusion 
coefficient in the lower range of those 
thought to be appropriate. The three winter 
mid-latitude data sets, all associated with 
anomalous D-region radio absorption, 
yielded higher NO concentrations, two pro¬ 
files attaining peak values of 10“ cm . 


Disturbed D-Region Modeling: Further 
progress was made in interpreting the many 
measurements taken during the November 
2-o. lfMift Polar Cap Absorption (PCA) 
event, or, solar proton event. Absorption 
data obtained during this event at d<> MHz 
(ordinary and extraordinary waves), IS 
MHz and 9 MHz for four rocket flights plus 
dl) MHz riometer data were shown to be in 
good accord with theoretical calculations. 
More recently, a model for this event was 
published which agrees quite well with the 
data except for sunrise conditions. The 
model does not include hydration processes 


for negative ions: this exclusion is a prin¬ 
cipal reason for the model’s disagreement 
with the data at sunrise. 

Laboratory Studies: During this report¬ 
ing period, the assembly and calibration of a 
high temperature mass spectrometer was 
completed. This instrument has been used 
to measure the thermochemieal properties 
of a number of metal oxides which are of 
interest in understanding the composition of 
the upper atmosphere. There are four 
classes of tnese metals. First, metals which 
are present in meteorites may orm oxides 
when they enter the earth’s itmosphere. 
Thermochemical data for these species are 



High temperature mass spectrometer. 









19 


needed to assess:, their importance in under¬ 
standing the chemistry of the natural at¬ 
mosphere. Second, metals are sometimes 
released in the earth's atmosphere to study 
specific geophysical phenomena, for ex¬ 
ample, winds or magnetic fields. The fate of 
these metals when they react with the 
atmosphere is determined by the thermo¬ 
chemical properties of their oxidation pro¬ 
ducts, and thermochemical data are needed 
to evaluate which products are formed. 
Third, metals are also released into the 
earth’s atmosphere by nuclear bursts in the 
atmosphere. Some of the fission fragments 
thus released can undergo reactions with 
the ambient to form metal oxides, and to 
evaluate this avenue of reaction, thermo¬ 
chemical data are often useful. Finally, 
metals are used as fuel additives in jet fuels, 
so that metals and their oxides are often 
released in the ambient. Thermochemical 
data are useful in evaluating the importance 
of these species as intermediates in main¬ 
taining or disturbing the chemical equilib¬ 
rium in the upper atmosphere. For the 
above reasons the thermochemical proper¬ 
ties of a number of metal oxides were 
studied: EuO, TiO_>, GdO, NdO, and PrO. 
Preliminary work has also been done on 
MgO and MgOH. 

In addition to the thermochemical work, a 
double mass spectrometer which is used to 
study ion-neutral collisions involving at¬ 
mospheric species has been modified to 
study the reactions between atmospheric 
ions (such as O’ and N*) with vibrationally 
excited atmospheric molecules (such as Na). 
This modification consisted of the addition of 
a beam modulation system and phase- 
sensitive detection to the apparatus. Pre¬ 
liminary data have been obtained for the 
reaction of 0* with vibrationally excited N », 
but the noise levels are at present quite 
high. Some experiments have also been per¬ 
formed to study the cross section for the 
reaction of Mg* with water. Qualitative first 
experiments indicate that a reaction occurs. 

To understand the composition of the 
metal-ion layer and how the chemical bal¬ 


ance leading to it is maintained, a survey 
was conducted of the thermochemical and 
kinetic data available for a number of metal¬ 
lic species which have bee 1 reported in the 
metal-ion layer. This survey has been pub¬ 
lished as a technical report. One conclusion 
of this study is that most of the metals will 
not form metal oxide ions. 

SOLAR ULTRAVIOLET RADIATION 

Solar ultraviolet (UV) radiation having 
wavelengths between 50 and 350C ang¬ 
stroms is completely absorbed by the 
earth’s atmosphere at altitudes above about 
15 km. This atmospheric absorption is the 
major source of heating in the earth’s 
stratosphere, mesosphere, and thermo¬ 
sphere and controls the neutral and charged 
particle composition and photochemical 
processes occurring in these regions. 
Measurements of the spectral distribution, 
the absolute intensities, and the temporal 
variability of solar UV radiation are neces¬ 
sary inputs to any study of the photo¬ 
chemistry of the earth’s atmosphere. The 
solar parameters as well as the altitude 
dependence of the absorption of the solar 
UV within the earth’s atmosphere are re¬ 
quired as input data for the development of 
atmospheric density and ionospheric 
models. Solar UV absorbed by the atmos¬ 
phere also provides the energy for produc¬ 
tion of the atmospheric airglow radiation 
which surrounds the earth. This is im¬ 
portant because if we understand the proc¬ 
esses that produce airglow radiation, we 
may be able to determine atmospheric 
parameters from satellite measurements of 
airglow radiation. 

Radiometric measurements of solar UV 
radiation are made with calibrated spec¬ 
trometers mated with solar pointing con¬ 
trols and carried by rockets and satellites to 
altitudes well above 100 km. The rocket 
payloads frequently carry electron spec¬ 
trometers and photometers to measure 
atmospheric photoelectron fluxes and UV 
airglow radiation. 






I 







20 


Rocket Measurements of Solar UV: The 

optical entrance apertures of the rocket- 
borne spectrometers are pointed at the 
center of the solar disk during data acquisi¬ 
tion. The flux emitted from the entire solar 
disk is measured, since the full disk flux is 
the important parameter for atmospheric 
studies. Photomultiplier detectors operated 
as photon counters record the solar inten¬ 
sities, and the data are telemetered to 
ground receiving stations. 

During this reporting period, several 
rocket experiments measured solar UV in 
the 1250 to .‘1500 angstrom range. Radiation 
in this wavelength region is particularly 
important to the stratosphere and meso¬ 
sphere. The absorption of solar UV between 
1200 and 2000 angstroms in the Schumann- 
Runge continuum and bands dissociates Oj 
This dissociation is an im()ortant energy 
source between 80 and 120 km and is the 
source of atomic oxygen throughout the 
thermosphere. The solar flux between 2000 
and .1500 angstroms is absorbed predomi¬ 
nantly in the stratosphere and mesosphere 
between about 15 and 80 krn by Oz and by 
other minor constituents such as ozone. This 
absorption controls the ozone balance in the 
stratosphere and many other photochemical 
reactions. On April 21, 1977 the first suc¬ 
cessful coordinated measurement by a 
rocket spectrometer and balloon-borne 
spectrometer was carried out. Both spec¬ 
trometers were Ebert-Fastie configura¬ 
tions and measured absolute fluxes in the 
wavelength region 1750 to 3500 angstroms 
with a spectral resolution of 0.1 angstrom. 
The rocket spectrometer measured abso¬ 
lute solar fluxes incident on top of the 
stratosphere, while the balloon 
spectrometer measured solar flux within 
the stratosphere where the flux is absorbed. 
These data, obtained simultaneously, will 
be used to study stratospheric photo¬ 
chemistry and to develop stratospheric 
models. 

A newly designed double Ebert-Fastie 
spectrometer flown in a rocket on August 9, 
1977 has provided data on solar U V fluxes in 


the extended wavelength region 1250 to 
2500 angstroms with a spectral resolution of 
0 1 angstrom. This instrument was again 
flown successfully on September 19, 1978. 
The data obtained from these two rocket 
experiments will provide an excellent data 
base on solar fluxes in the wavelength 
region of importance to the stratosphere 
and mesosphere. 

A promising method of obtaining atmos¬ 
pheric densities remotely from a satellite 
consists of measuring the intensities of 
atmospheric emission of the molecular 
nitrogen second positive band at 3371 
angstroms and the atomic oxygen inter¬ 
combination line at 1356 angstroms. These 
airglow emissions measured at the satellite, 
when deconvoluted, can be used to infer the 
atmospheric densities of molecular nitrogen 
and atomic oxygen. Future DMSP satellites 
will contain airglow photometers to make 
these measurements. To verify the remote 
sensing capability of the DMSP satellite, a 
rocket payload has been instrumented and 
will be flown in 1979 in coordination with 
overhead passes of the DMSP satellite. The 
rocket experiment will obtain in situ 
measurements of solar UV intensities, 
neutral particle densities, photoelectron 
energy distributions, and molecular nitro¬ 
gen and atomic oxygen airglow radiation at 
3371 and 1356 angstroms, respectively. The 
in situ rocket measurements will allow the 
interrelated atmospheric processes and 
parameters leading to airglow radiation to 
be measured and applied to the verification 
of the DMSP density measurements. Data 
on the atmospheric photoelectron fluxes 
obtained previously in a test flight of this 
rocket payload have now been analyzed and 
published. The photoelectron fluxes were 
obtained with a 127-degree cylindrical elec¬ 
trostatic deflection analyzer consisting of 
entrance and exit slit aperture assemblies, 
deflection plates, and a channeltron detec¬ 
tor operated as an electron counter. Energy 
scanning is accomplished by varying the 
differential voltage applied to the deflection 
plates. One complete energy scan is 



21 


obtained in 1.3 seconds; therefore, the 
photoelectron energy distribution can be 
obtained as a function of altitude in the 
earth’s atmosphere. The data obtained from 
the test flight of the electron spectrometer 
have provided the first measurements of the 
relative values of thermospheric photo¬ 
electron fluxes with high energy and alti¬ 
tude resolution. 

Satellite Measurements of Solar UV: 

Satellite-borne instrumentation affords the 
opportunity for nearly continuous solar flux 
measurements over extended time periods. 
Such measurements allow one to determine 
temporal variations of solar UV that occur 
during the 27-day solar rotation and during 
the 11-year solar cycle. There is active con¬ 
troversy concerning the variations of solar 
UV during the 11-year cycle, primarily 
because no systematic program to mesisure 
these fluxes with high accuracy and ex¬ 
tended wavelength coverage during a com¬ 
plete cycle has ever been carried out. The 
UV spectrometers, designed and supplied 
by AFGL as part of the three payloads of 
the NASA Atmosphere Explorer (AE) 
series satellites, have provided the most 
significant information to date on the varia¬ 
tions of solar UV with solar activity. AE-C 
was launched during December 1973, and 
AE-D and AE-E were launched during 
October and November 1975. The opera¬ 
tional lifetimes of both AE-C and AE-E 
have exceeded their design lifetimes by 
several years. Although AE-C is no longer 
operating, AE-E is expected to operate well 
into 1980. These AFGL spectrometers, 
therefore, will have provided data on solar 
U V for a period of about seven years. 

Several significant results on the varia¬ 
tion of solar U V radiation with solar activity 
obtained from the AFGL spectrometers 
have been published. A particularly im¬ 
portant result obtained from the AE-C 
spectrometer is that the minimum value of 
solar UV fluxes occurred about 14 months 
earlier than the minimum sunspot number 
of July 1976. This discovery of a major phase 


difference between the solar UV flux 
minimum and solar sunspot cycle minimum 
can have a major impact on the development 
of atmospheric and ionospheric models. 
Existing models are based on the assump¬ 
tion that solar UV fluxes, which are the 
major source of energy input in the upper 
atmosphere, are in phase with the sunspot 
number and the related 10.7 cm solar radio 
emission. Another important result is the 
unexpected rapid increase in solar UV flux 
during the development of the new solar 
cycle which began in July 1976. The increase 
in flux appears to be well correlated with the 
increase in the 10.7 cm solar radio emission, 
in sharp contrast to observations made 
during the previous solar cycle when the 
correlation between solar UV and 10.7 cm 
emission was poor. 

ATMOSPHERIC ULTRAVIOLET 
RADIATION 

The emission from the atmosphere in the 
wavelength region 1100-4000 angstroms can 
be observed from space, and offers the 
possibility for several applications. These 
include detection and surveillance of mis- 



The vacuum ultraviolet radiation background 
presented by the earth, as measured from a 
satellite. Experiment CRL-246 measured 
global VU V radiation levels, with emphasis on 
the levels between the bright atmospheric 
emission bands. It also measured the local 
variability and enhancement, typified by the 
auroral emissions at high latitudes and the 
crossed equatorial bands. 



siles based on their UV exhaust plume 
intensity, remote sensing of atmospheric 
conditions such as electron density and 
species concentrations, and development of 
improved earth horizon sensors based on 
the distinctive UV limb profile. 

Missile Exhaust Plumes: As part of 
AFGL's Multispectral Measurements Pro¬ 
gram (MSMP), the UV radiation emitted by 
missile exhaust plumes is measured. In this 
program, spatial and spectral data on small 
operational bus engines are obtained using 
an Aries rocket which carries the target 
engine and a multis|>eetral sensor module. 
At altitude, the two are separated ami a 
series of observations of the target are 
made. For this work, it was necessary to 
develop two ty|tes of new digieon imaging 
detectors for the UV. These were success¬ 
fully completed and flown on the first MSMP 
launch. Several additional launches are 
planned to find the effects of solar illumina¬ 
tion, thrust level, and target velocity. 

UV Backgrounds: In addition to missile 
exhaust plume measurements, atmospheric 
UV background intensities are needed to 
develop surveillance and tracking systems. 
The properties of the background are re¬ 
quired to predict the signal-to-noise ratio 
and wavelength bands to be used. The 
major accomplishment in this area has been 
the success of the satellite ex|H*riment, 
VUV Backgrounds. This ex|K»riment was 
launched in March 1W7N as part of SAMSO's 
Space Test Program flight S77 2, and it has 
returned excellent data on the spatial and 
spectral characteristics of the earth’s 
atmosphere as viewed from space. The 
wavelength range of 1 l(Mlto2!HtO angstroms 
was covered with a dual Kbert-Fastie 
s|H*ctrometer, and spatial structure to 1 km 
was obtained along the ground track for four 
VUV filter bands. In addition to measuring 
the long-term stability, intensity, and 
variability of the earth’s radiance, new 
observations were made of the UV' aurora 
and the tropical UV’ airglow. 


UV Horizon Sensor: The design of a 
shuttle experiment, designated AFGL-K01. 
Horizon Ultraviolet Program, has been 
initiated. This exjjeriment will obtain the 
earth limb radiance profiles to allow design 
of more accurate spacecraft horizon sen¬ 
sors. The basic concepts and instrumentation 
come out of the experience on CRL-2415. In 
addition, the new results available will 
enable sensitivities of the instruments to be 
set more exactly. 



The flight instruments for the CRL-Z48 
experiment. 


UV Missile Warning Receivers: An im¬ 
portant step in the flight programs de- 
scribed has been the development of a 
calibration facility to enable test and radi¬ 
ometric calibration at AFGL This effort 
has led to participation in an im|H>rtant 
triservices program to develop UV missile 
warning receivers for low-flying aircraft 
and helicopters. Previously, there has been 
difficulty establishing standard UV calibra¬ 
tions sufficiently reliable for flight tests, 
ground chamber tests, and various tv|>es of 
sensors. Our measurements of these re¬ 
ceivers help to place laboratory and flight 
observations on a common basis. 

NEUTRAL ATMOSPHERIC DENSITY AND 
STRUCTURE 

Measurements of the neutral atmospheric 
mass density, tem|>erature. s|>ecies den¬ 
sities. winds, turbulence, and other param¬ 
eters have provided a general knowledge of 
the properties of the mesosphere and 



23 


thermosphere. These measurements, ob¬ 
tained by racket and satellite experiments, 
have provided the basic data for formulating 
empirical static models, such as the U.S. 
Standard Atmosphere 197(5, and for testing 
current theoretical and dynamic models of 
the upjrer atmosphere. Understanding 
some of the properties has raised other 
questions of importance. For example, 
atmospheric tidal components and ampli¬ 
tudes must be described and included in 
models, and the sources and amplitudes of 
propagating waves in the upper atmosphere 
are just now being given serious attention. 
Dynamic models must not only include the 
time variation of the mass density and tem¬ 
perature but also accurately model the 
variation of individual s|>ecies. 

Other major concerns are the spatial and 
temporal variations of eddy diffusion and 
the height of the turbopause. These affect 
the conqmsition of the mesosphere and 
thermosphere, the distribution of excited 
states of mesospheric and thermospheric 
species, the densities of minor species in the 
mesosphere and thermosphere, and the 
variations of K- and F-regior. ion species. 
Several recently develo|>ed techniques have 
begun to help in answering these questions. 

Rocketbome Accelerometer Density 

Measurements: From 197(5 to 197#. the 
Atmospheric Structure Branch sup|>orted 
three Air Force programs s|Minsored by the 
ABRKS Program Office of SAMSO. The 
reentry studies being conducted by ABRKS 
required accurate knowledge of the atmos¬ 
pheric density along the reentry corridor for 
their tests. In August 1970. a Density 
Measurements Program was conducted at 
Kwajnlein Missile Range (KMR). The best 
available techniques were used to obtain a 
set of measurements. The results were used 
to determine the variability of the atmos¬ 
phere in time and space. Error estimates for 
each of the techniques were reviewed and 
the techniques were compared. The instru¬ 
ments used included the rawinsonde. 
rocketsonde, Jim sphere, Robin sphere, and 


AFGL’s accelerometer sphere. This pro¬ 
gram showed that the atmosphere was 
sufficiently variable above (50 km to require 
careful planning where accurate knowledge 
of the atmosphere is needed. Gravity waves 
and turbulent layers were found to cause 
significant differences in mesospheric den¬ 
sities when periods of more than an hour and 
distances of a hundred or more kilometers 
were considered. This study at KMR pro¬ 
vided radar tracking data of considerably 
better accuracy than any previous measure¬ 
ments and thus required less smoothing 
than usual for analysis of the Robin data. 
The small scale wave structure of the 
mesosphere could now be seen in the Robin 
density results. The accelerometer results 
were obtained using the recently developed 
PZI, Densitometer. This piezoelectric accel¬ 
erometer is the only technique available 
that provides high resolution (approxi¬ 
mately 100 meters) measurements accurate 
to 5 |>ercent in the mesosphere and lower 
thermosphere (the region between 50 and 
150 km). All of the techniques agreed well in 
the regions of overlap. For the first time, 
the atmospheric density and temj)erature 
could be well defined from 0 to 150 km using 
a rawinsonde (0-30 km), rocketsonde (25-00 
km), Robin sphere (40-90 km) and the 
AFGL accelerometer sphere (50-150 km). 
In addition, some information on the scale 
and amplitude of gravity waves, the space 
variability and time variability were obtained. 

The second Density Measurements Pro¬ 
gram at KMR was conducted in conjunction 
with the Technology Development Vehicle 
Program in May 1977. A reference atmos¬ 
phere for the reentry corridor could be con¬ 
structed using the results obtained with the 
various techniques to determine the mean 
atmospheric properties. 

In April 1978, a third program was con¬ 
ducted at KMR in support of the Thrusted 
Replica Program. AFGL scientists 
gathered all of the data from the various 
techniques rind developed a reference pro¬ 
file for the atmospheric properties. Con¬ 
fidence limits were placet! on each profile 




24 


based on the errors associated with each 
measurement and on the spatial and tem¬ 
poral separation. 

These studies have now provided the 
most complete set of atmospheric prop¬ 
erties available at one location. Using these 
results, the wavelengths and amplitudes of 
gravity waves can be studied and the vari¬ 
ability of the atmosphere in turbulent layers 
can be shown. 

The PZL Densitometer experiment used 
in these measurement programs is a three 
axis piezoelectric accelerometer. The in¬ 
strument consists of three proof masses 
suspended on sensitive piezoelectric crys¬ 
tals so that their center of mass is located at 
the center of a sphere 25 centimeters in 
diameter. The sphere contains all of the 
experiment support hardware, a telemetry 
system and a radar beacon transponder. 
The piezoelectric crystals produce a voltage 
when the crystal is strained by the atmos¬ 
pheric drag acceleration force. The high 
sensitivity of the instrument allows meas¬ 
urements to be made to altitudes above 150 



^ 'f ) m r 't o $e iT•« "* .oc i it i it ■ »o ■ «o 

Of NS lt» nf 5J*f D "OOt i 


Mass density measurements from the PZL 
Densitometer experiment are Bhown as a ratio 
to the USSAS '66 15 degrees N annual model. 
Each point represents an individual measure¬ 
ment of the density. The wave structure in the 
profile is partly due to gravity waves propa¬ 
gating through the mesosphere. 


km. The high space and time resolution of 
the instrument means that small scale 
structure can be measured with a resolution 
of about 100 meters. 

The recent measurements at KMR are 
now being combined into a new KMR 
Reference Atmosphere. The new model is 
being prepared by scientists from the Aero- 
nomy and Meteorology Divisions of AFGL 
with input from a committee made up of 
scientists from several DOD agencies and 
contractors. The new model is being pre 
pared at the request of Army and Air Force 
offices concerned with programs at 
Kwajalein Missile Range. The model will 
serve as a basis for mission planning and will 
be used as a standard for comparison of 
future measurement programs. 

Satellite Accelerometer Density Meas¬ 
urements: An extensive atmospheric 

density data base has been developed using 
accelerometer results from four low altitude 
satellites. The data were obtained with the 
NASA Atmosphere Explorer (AE)-C, -D, 
-E Satellites and the Air Force SI-1 satel¬ 
lite. Measurements made on more than tiOOO 
orbits during the period January 1974 to 
November 197t5 were utilized. The altitude 
range of this data base is from 250 km down 
to as low as 140 km. Latitude coverage is 
from 90 degrees N to 90 degrees S and local 
time coverage includes several 24 hour 
cycles. Data were obtained over a wide 
range of geomagnetic conditions. Solar flux 
was generally quite low during the period of 
measurement. The data were compared to 
current atmospheric models to determine 
the magnitude of unmodeled density vari¬ 
ations. This analysis showed that the ac¬ 
celerometer data will [>ermit significant im¬ 
provement in our understanding of the 
variations in lower thermospheric density. 
An empirical model is being developed to 
describe the accelerometer data in terms of 
variations with geomagnetic activity, solar 
flux, latitude, local time and the semiannual 
effect. This work is an extension of the 
model developed using only AE-C data as 
described for the previous reporting period. 






25 


A statistical analysis of the density re¬ 
sponse to geomagnetic activity observed 
with the AE-C data was made. This study 
showed that the commonly used Jacchia 
1971 atmospheric model, based primarily on 
satellite orbital decay data, underestimates 
the variation in lower thermosphere den¬ 
sities related to geomagnetic activity. Also, 
the data showed that the thermospheric 
response during large geomagnetic storms 
was greater at higher geomagnetic lati¬ 
tudes. For small and medium storms no 
significant variation of the res|»onse was 
found with geomagnetic latitude. This study 
is being extended, using the entire data 
base, to develop a more accurate description 
of the geomagnetic activity effect as a 
function of latitude and local time. 

The AE-E data were analyzed to deter¬ 
mine near-equatorial diurnal and semi¬ 
diurnal tidal variations in the lower ther¬ 
mosphere. Results showed that the local 
time density structure changes from pre¬ 
dominantly semidiurnal below ISOs 5 km to 
predominantly diurnal above this transition 
height. A seasonal difference in the phase 
structure of the semidiurnal density com¬ 
ponent was observed. Also, the phase of the 
diurnal variation shifted to earlier times 
with decreasing altitudes. The Jacchia 1971 
model incorjMiratos a constant phase as a 
function of altitude for the diurnal variation, 
and does not incorjMirate density variations 
with a semidiurnal com|K»nent. The total 
data base is being studied to extend the tidal 
analysis to all latitudes. 

A new single proof-mass triaxial accel¬ 
erometer was developed. This instrument 
reduces by about a factor of three the 
power, weight, size and cost requirements 
previously encountered by flying thre? 
orthogonal single axis units. A total of six 
instruments were fabricated for flight in 
conjunction with the Defense Mapping 
Agency NAVPAC Program. Objectives of 
the accelerometer are to improve satellite 
ephemeris determination, to provide den¬ 
sity data for use in atmospheric modeling, 
and to improve gravity field models. The 


first instrument was launched in June 1977. 
All three axes provided acceleration data. 
However, the axis aligned with the drag 
vector showed an anomalous response to 
temperature. This precluded obtaining high 
accuracy density data. The second instru¬ 
ment, modified to reduce thermal response, 
was launched early in 1978. Data were 
obtained over a six month period and are 
currently being reduced. 

Analysis of AE elliptical orbit data 
showed that the accelerometer bias ex¬ 
hibited a temperature dependence. For 
density measurements on non-spinning sat¬ 
ellites in low, near-circular orbits there is no 
way to determine the bias. ROCA (Rotat¬ 
ing Calibration Accelerometer) was de¬ 
signed to provide accurate density measure¬ 
ment by routinely determining bias. ROCA 
was sensitive along a single axis which could 
be rotated by 90 degrees. When aligned 
perpendicular to the velocity vector, the 
bias was measured. ROCA was flown as 
part of the S3-4 satellite. S3-4 was launched 
into a near polar orbit, with perigee near 170 
km, in March 1978. The instrument per¬ 
formed as expected and data are being re¬ 
duced. 


Satellite Ionization Gauge Density 

Measurements: Data obtained from the 
S3-1 satellite have been completely reduced 
and processed into neutral density results. 
These measurements have been edited 
further to remove noise and compiled into a 
data base which can be processed by a 
computer for use in atmospheric structure 
studies and analysis. Measurements from 
the S3-2 satellite flight are currently under¬ 
going the same processing procedures and 
being compiled in the same manner as were 
the S3-1 ionization gauge measurements. A 
data base which includes measurements 
from over 3000 orbits, will be generated as a 
final product from the two flights. The 
theory and techniques employed have been 
documented and published along with rep¬ 
resentative data samples. Current analysis 



26 


of the S3-1 data measurements have indi¬ 
cated hemispherical asymmetry in the re¬ 
sponse of the atmosphere to geomagnetic 
disturbances. Atmospheric density in the 
southern hemisphere shows a greater en¬ 
hancement than the northern hemisphere. 



The PFA flight unit. 


The Air Force S.'t-4 satellite was launched 
during March 1978. Two density measuring 
payloads were designed and constructed for 
use on this satellite. The newly developed 
payloads were designated the S737 Particle 
Flux Accumulator (PFA) units because, in 
addition to measuring atmospheric neutral 
density, the units could operate in a sec¬ 
ondary mode to measure the satellite’s atti¬ 
tude (attack angle). Also, under the proper 
conditions, the PF A’s secondary mode could 
be used to determine neutral gas tem¬ 
peratures and detect atmospheric winds. 
The S3-4 satellite was launched into a near 
circular polar orbit with a perigee of 163 km 
and an apogee of 263 km. The orbit inclina¬ 
tion was 96.3 degrees. Neutral density was 
measured during a six month period with 
over 1000 orbits of data being acquired. One 
of the most interesting effects observed was 
a persistent trough seen primarily over the 
southern polar cap region and almost ex¬ 
clusively confined to early morning hours. 


S3-4 NEUTRAL DENSITY MEASUREMENTS 

PofticN Fkia Accumulator Eaparimant 
NEUTRAL DENSITY PHENOMENA — Dantity Trough! 



UT ?)?■ 
ALT 17 * 

LAT -47' 
LT 0*34 


«•» 425 
04/11/79 


I 


9 394 2340 

734 744 

9 7* -41* 

0 4 2 1 0147 


X 






UT 00 4* 
ALT 939 

LAT 34* 
LT 0444* 


003) 

143 

4** 

04 i 2 


0037 

?S4 

*)• 

0414 


Atmospheric Trough Phenomena observed 
from the Air Force S.I-4 satellite. 


Measurements of the trough show distances 
varying from 800 to 4000 kilometers along 
the satellite path. Similar troughs were 
observed in the SI-1 data but were seen only 
infrequently. 

The secondary mode operation of the 
PFA unit was also flight tested in the six 
month period. The attitude angle of the pay- 
load was measured within 1 degree of its 
alignment position. 

THEORETICAL DENSITY STUDIES 

Satellite orbital studies have been pri¬ 
marily aimed at deriving atmospheric den¬ 
sities from orbital decay, and developing 
and evaluating density models for use in 
predicting satellite ephemerides. Drag 
analyses using Doppler Beacon data from 
three low-altitude satellites (DB-7, DB-8, 
and DB-9) were compared with results from 
A DCOM radar skintrack and Satellite Con¬ 
trol Facility (SCF) Space-Ground Link Sub¬ 
system observations for the same satellites. 




27 


The major results were: (1) Predicted posi¬ 
tions computed solely from skintrack or 
SCF data contain relatively large errors due 
to inaccuracy in the calculated orbital 
elements. These errors are minimal for the 
Doppler Beacon data, thus allowing a much 
improved estimate of the errors due to 
atmospheric drag. (2) The high accuracy of 
the Doppler Beacon data permits shorter- 
term fit spans over which the drag can be 
determined, allowing study of higher- 
frequency density fluctuations. (3) Skin- 
track data yield equally good accuracy for 
longer-term density variations. (4) 
Ephemeris prediction errors for low-per¬ 
igee satellites will increase significantly 
during the next two or three years due to 
the increase in solar activity. 

The accuracy of six thermospheric models 
(U.S. Standard Atmospheres 1962 and 
1976, DENSEL, MSIS, and Jacchia 1971 
and 1977) were evaluated by statistical 
comparison with data from the Miniature 
Electrostatic Accelerometer (MESA) and 
Open Source Spectrometer (OSS) experi¬ 
ments aboard the Atmosphere Explorer-C 
satellite. The altitude range was 160-200 
km, and over 3400 measurements of total 
mass density from the MESA experiment 
and 1700 measurements of 0, N 2 and Ar 
number densities from the OSS experiment 
were considered. The ratio R between the 
measured density and the model density 
was analyzed statistically. Frequency dis¬ 
tribution plots of R, and tables containing 
the mean value of R and its standard devia¬ 
tion were constructed for different levels of 
magnetic activity and compared between 
the models. Even the most recent models 
indicated standard deviations of over 15 
percent for total mass density and 20-30 
percent for 0 and N 2 . This indicates a need 
for continued in situ measurements in the 
upper atmosphere and a new generation of 
models in which variations in 0, O 2 , N 2 and 
He are considered in conjunction with 
thermospheric circulation systems. 

The Jacchia 1977 and MSIS density 
models were compared with several older 


models for accuracy and efficiency in pre¬ 
dicting satellite ephemerides for satellites 
with perigee altitudes ranging from near 
170 km to 800 km. While both models com¬ 
pared favorably in accuracy with the Jacchia 
1964 and 1971 models, the Jacchia 1977 
model required more computer processing 
time than the older models because of the 
number of table look-ups, and the MSIS 
model required more computer time be¬ 
cause it contains complicated functions. A 
simple analytic version of the Jacchia 1977 
model similar to the Jacchia-Walker-Bruce 
model is being developed. 

Work has continued on the theoretical 
modeling of tidal variations in thermo¬ 
spheric composition and total mass density. 
A formalism including photochemistry, ion 
chemistry, thermal diffusion, exospheric 
transport, and specified winds and tem¬ 
peratures was used to develop a model of 
tidal variations in composition and density. 
Diurnal and semi-diurnal changes in O, 0?, 
N 2 , Ar, He and H at minimum and maxi¬ 
mum levels of sunspot activity were ob¬ 
tained. Sunspot minimum calculations 
showed excellent agreement with equa¬ 
torial measurements of 0 and N 2 , both in 
amplitude and phase for diurnal and semi¬ 
diurnal variations between 220 and 280 km. 
The major exceptions were the equatorial 
diurnal amplitude of Ar, which the model 
overestimated by 35 percent, and the 



Theoretically computed ratios of semidiurnal 
to diurnal amplitudes of 0 and N 2 at 0 degrees 
latitude (solid curves) and 40 degree latitude 
(dashed curves) for (left) SSM1N and (right) 
SSMAX. Results from the San Marco 3 NACE 
experiment are designated by open circles for 
O and solid circles for N->. 






28 


equatorial diurnal amplitude of He, which 
the model underestimated by about 25 per¬ 
cent. Computations for sunspot maximum 
conditions demonstrated substantial solar 
cycle differences in the vertical profiles of 
amplitude and phase for each constituent 
and in the relative contribution of semi¬ 
diurnal and diurnal components at different 
latitudes and heights. Consequently, con¬ 
tinued satellite mass spectrometer and 
accelerometer measurements over different 
levels of solar activity are needed for the 
development of comprehensive empirical 
models of thermosphere tides. 

Recent mesospheric and lower thermo¬ 
spheric data and models were reviewed. 
Data for these regions of the atmosphere 
were provided by measurements with in¬ 
strumented rockets and satellites and 
ground-based detectors, including photo¬ 
meters, partial reflection and incoherent 
backscatter radars. The quantities and 
types of data for the lower thermosphere 
have expanded dramatically during the past 
few years, primarily due to increased data 
from incoherent backscatter radars and low 
altitude satellites. Major emphasis in the 
review was placed on the development of 
tidal models and of systematic variations 
with season and latitude of turbulence in¬ 
tensity and turbopause altitude. Joule and 
particle precipitation heating rates have 
been derived from Chatanika incoherent 
scatter data. Recent models of excitation 
and propagation of gravity waves and global 
circulation patterns during magnetic storms 
were reviewed and compared with satellite 
data. 

In a review paper on recent atmospheric 
models, Dr. Jacchia (Smithsonian Astro- 
physical Observatory) described the OGO-6 
model (1974) based on data collekted within 
a limited range of height and solar activity 
(solar maximum) as a first step toward a 
new generation of models. The ESRO-4 
model (1977), based on data reco.'ded at 
lower heights and lower solar activity, was 
similar in scope to the OGO-6. The Jacchia 
1977 model, based on a synthesis of tem¬ 


perature, mass-spectrometer and total 
density data, was compared to the MSIS 
model (1977), based on incoherent-scatter 
temperatures and mass-spectrometer data 
from various sources. 

GEOPOTENT1AL MODEL STUDIES 

Two methods were developed for reduc¬ 
ing the number of tesseral and sectoral 
terms in large geopotential models for use 
with a particular satellite orbit. One 
method, optimization, selected only those 
terms whose individual perturbation ampli¬ 
tudes exceeded a specific tolerance. The 
other method, abbreviation, discarded 
terms whose total contribution to the 
ephemeris prediction error at a specified 
time was less than a specified value. The 
ephemeris prediction accuracy obtained 
with these reduced models compared favor¬ 
ably with that obtained with the full mudel, 
while saving up to 50 percent of the com¬ 
puter time. 

WINTER MESOSPHERE 
MEASUREMENTS 

Several interesting new results were ob¬ 
tained from rocket measurements made in 
January 1976. NASA, Air Force, and uni¬ 
versity scientists planned a coordinated 
rocket program to study the properties of 
the midlatitude Winter Anomaly. Because 
of problems w ith payloads and w ith severe 
weather, the measurements could not be 
made on an anomalous day. However, mea¬ 
surements were made on a normal day for a 
planned comparison. Rocket payloads con¬ 
taining a liquid helium cryosorption pumped 
mass sjiectrometer and a chemical smoke 
trail were launched by AFGL scientists 
from Wallops Island. Virginia, on 28 Jan¬ 
uary 1976. The day would be classified as a 
normal winter day based on the absorption 
and partial reflection data used to character¬ 
ize the D-region. This day immediately 
followed a disturbed period, however. 




29 


( 


1 

1 


i 


t 


l 



A09 404-2 
23 JAN 76 
WALLOPS ISLAND, VA 


10 10 10 10 ? 10 * 

SPECIES DENSITY (cm') 

Density profiles of the major atmospheric 
species measured at Wallops Island, Va., on 
January 2%, 1976. The measurements were 
obtained using a mass spectrometer with a 
liquid helium cryopump. 

The results from the mass sj>ectrometer 
were considerably different from any mea¬ 
surements previously obtained. Four par¬ 
ticular features distinguished these data. 
First, the Ar Nj separation from ground 
level mixing ratio occurred at a very low 
altitude, near 93 km. Second, the atomic 
oxygen exhibited the hiphest i>eak density 
observed with this instrument, about 
»i* 10" atoms cm . Third, the altitude of the 
l>eak in the atomic oxvpen density was low. 
near 84 km. Fourth, a rather stronp wave 
structure was observed in the altitude pro¬ 
files of the sjtecies. All of these features 
would be consistent with a |>eriod of low 
eddy diffusion rates based on the theoretical 
models develo|>ed ny AFGI. scientists. The 
low altitude separation of arpon (40 amu) 
from the mixed atmosphere ratio is a sure 
indication of low turbulent diffusion coeffi¬ 
cients in the repion near 90 km. The hiph 
density of atomic oxvpen with a peak at low 
altitude indicates a reduced rate of diffusion 
to lower altitudes where atomic oxypen is 
lost by three-body recombination. The wave 
structure may well be associated with prop- 
apatinp pravitv waves which are less likely 
to be dissipated in the mesosphere if tur¬ 
bulent layers are absent. 


The winds were measured using a titan¬ 
ium tetrachloride and water release to pro¬ 
vide a smoke trail which was photographed 
to determine the structure in the meso¬ 
sphere. The wind structure was accurately 
determined between 50 and 90 km with a 
resolution of the small scale structure to 
about 50 meters. Within the same hour, a 
third rocket was launched to release a Robin 
sphere experiment of the Army Atmos¬ 
pheric Sciences Laboratory. The passive 
sphere was tracked by radar to provide 
density, temperature and wind results. The 
wind measurements from the passive 
sphere agreed well with the chemical trail 
up to about 70 km and then started to di¬ 
verge. This is not unexpected because of the 
smoothing required for the radar data and, 
possibly, the variation with time of the 
winds. The temperature results from the 
sphere were used, together with the wind 
data, to calculate the Richardson number. A 
Richardson number of less than ‘A is a good 
indicator of the presence of turbulence in 
the region. The turbulent analysis shows 
that a significant fraction (approximately 30 
percent) of the altitude region from 50 to 65 
km was turbulent. The region above 65 km 
appeared to be very stable, even though 
there were large wind speeds (approxi¬ 
mately 80 m/sec) present. This study would 
indicate a lower degree of turbulence than 
normal in the mesosphere. 

The results from the mass spectrometer 
and from the turbulence analysis provide a 
consistent characterization of the conditions 
of a very stable mesosphere. The question 
that still remains is whether to associate 
this condition with the normal winter meso¬ 
sphere or with the recovery phase following 
a disturbed period. 

Rocket Messurwmnf of Thermo¬ 
spheric S pe c ies: A mass spectrometer has 
been developed to measure densities of the 
primary neutral species in the 120 to 200 km 
region accurately. The instrument will also 
be used to determine the gas kinetic 
temperature from measurements of the 
velocity distribution of nitrogen molecules. 



I % 



30 


A first test flight of the instrument on 24 
September 1977 was degraded by the gas 
release from the Attitude Control System 
nozzles. A second flight is planned in 1979 as 
part of a coordinated measurement pro¬ 
gram, with care taken to minimize the ef¬ 
fects of the Attitude Control System gas 
release. 

SATELLITE MEASUREMENTS OF 
COMPOSITION 

Neutral Species Densities: The mass 
spectrometer measurements from the S3-1 
and S3-2 satellites of the densities of atomic 
oxygen (0), molecular nitrogen (Nj), argon 
(Ar) and atomic nitrogen (N) have helped to 
answer questions about the thermosphere. 
The large changes (greater than a factor of 
10) in argon density in the 160 km and above 
region at high latitudes have shown that 
there must be large changes in atmospheric 
properties in these regions during geo¬ 
magnetic storm periods. Changes must oc¬ 
cur in the temperature profile and in the 
lower boundary (i.e. the turbopause level) 
and a convective flow or upwelling of heated 
atmospheric gases may also occur. Some of 
the S3-1 results were considered in deduc¬ 
ing the geomagnetic effects in the Jacchia 
1977 atmospheric model. 

The low altitude satellite results from S3- 
1 have also produced the first identification 
of the momentum source which was postu¬ 
lated theoretically about ten years ago. The 
momentum source effect is an in-phase 
response of all of the constituents. It results 
from localized pressure gradients which are 
set up due to momentun transfer from the 
ionized species moving under the influence 
of an electric field. Momentum source ef¬ 
fects have been observed jn about 30 orbits 
and occur in most cases when Kp is greater 
than 4 and when measurements were ob¬ 
tained at latitudes above 70 degrees for 
altitudes between 160 and 200 km. The 
density departure from a smooth latitude 
variation can be as large as 40 percent over a 
few degrees in latitude. 



Density profiles of the atmospheric species 
densities and mass density measured by the 
MSI spectrometer on the S3 1 satellite. This 
orbit shows the effect of a momentum source 
acting on the netural atmosphere, character¬ 
ized by the density trough near 200 km. 


Ion SpaclM Donsitlos: The mass spec¬ 
trometer experiments on the S3-1 and S3-2 
satellites have provided an excellent data 
base to study the properties of the F-region 
of the ionosphere. The effects of geomag¬ 
netic storms on the high latitude ion den¬ 
sities are striking. During these periods, 
the normal F 2 peak is at times completely 
removed by the loss processes due to storm 
changes in the neutral species and conse¬ 
quent changes in the chemistry. The molec¬ 
ular ions NO* and O 2 * can become the 
dominant ion species to altitudes of 400 km. 
The electric fields in the polar cap region 
frequently cause such irregular structure, 
with changes in density of a factor of 100 to 
1000 in tens of kilometers, that it can be 
difficult to sort out the various features. 
Some of the properties of traveling iono¬ 
spheric disturbances and scintillations can 
also be studied from the data. Efforts have 
begun to prepare an ionospheric F-region 
empirical model based on the data set. 




31 


LABORATORY MEASUREMENTS OF 
ION REACTION KINETICS 

Photodissociation and collisional dissocia¬ 
tion are two of several types of reactions 
which molecular ions may undergo in the 
atmosphere. Laboratory studies provide 
data on the cross sections and mechanisms 
of these reactions. Such data are required 
for the computer models used to predict the 
effects of natural and nuclear perturbations 
on atmospheric composition and density. In 
addition, the laboratory studies provide 
fundamental information on ion structures, 
bond dissociation energies, and spectro¬ 
scopic energy levels. These ion dissociation 
reactions are studied using double mass 
spectrometer systems in which a mass 
analyzed beam of the desired ion species 
collides either with photons or with neutral 
molecules, and the ionic products of the 
reaction are mass and velocity analyzed. In 
the case of ion photodissociation, the pho¬ 
tons are produced by a dye laser tunable in 
the wavelength range from 260 to 700 nm, 
with a bandwidth of about 0.1 nm. 

(Muster ions are among the dominant ion 
species in the lower mesosphere and upper 
stratosphere. The hydrated oxonium ions 
H.tO . Hj() and HsO . 2 H 2 O are of particular 
interest. Recent work in the Aeronomv 
Division has shown that, despite their 
rather weak chemical bonds, these species 
are surprisingly stable to photodissociation. 
In this work. up|>er limits to the photodis¬ 
sociation cross sections for HaO'.H^O ami 
H:j() ' . 2 H 2 O were measured for wave¬ 
lengths between 265 and 529 nm. Similarly, 
the hydrated negative hydroxyl ion, OH 
H 2 O, for which dissociation to OH + H 2 0 
requires an energy’ input of only 1.08 eV, 
was found to be stable to photodissociation 
at several wavelengths between 504 and 650 
nm, and only up|>er limits to the cross 
sections could be determined. 

In other work on ion photodissociation, 
absolute cross sections were measured for 
the photodissociation of vibrationally ex¬ 
cited Ar_>' formed by associative ionization. 


The tunable dye laser was found to be a 
useful probe of the vibrational distribution 
of these dimer ions. 

In studies of the photodissociation of the 
nitrogen oxides, it was determined that ex¬ 
cited nitrogen atoms N( J D) are produced in 
the photolysis of N 2 0\ No photodissocia¬ 
tion of N02 could be observed, and upper 
limits for the cross sections were measured. 

Research on collision induced dissociation 
reactions included studies on CO 3 . NO 3 , 
OH .HNOs, OH .H 2 0. and OH ,2H 2 0. 
Cross sections were measured for reactions 
of these ions with argon, nitrogen, and oxy¬ 
gen in the range of interaction energies from 
0.2 to 10 eV. and bond dissociation energies 
wvre determined. As a result of this work, 
ionic isomers were identified for some of the 
species studied. The existence of such struc¬ 
tural variants is important to the subse¬ 
quent chemistry involving these species. 
Cross sections were also measured for sev¬ 
eral “switching" reactions of the cluster 
ions. Examples are the reactions of OH 
. H 2 0 with CO 2 , SO 2 , and NO 2 , in which the 
neutral reactant replaces the H 2 0 in the 
cluster ion, producing the more stable ions 
OH .CO 2 . OH .SO 2 . and OH .NO>. re- 
spectively. The first two of these are the 
bicarbonate ion and the bisulfite ion. both 
well known in solution chemistry. 

These switching reactions are very fast 
over a wide range of interaction energies 
and represent a major sink for hydrated 
hydroxyl ions in the atmosphere. 


CHEMICAL-TRANSPORT MODELS 

The coupling of mean mass motions and 
other transport mechanisms to chemical 
production and loss processes demonstrate 
the variability that turbulence changes can 
produce in the neutral and ionic species dis¬ 
tributions. It is demonstrated that diumally 
varying photodissociation of O 2 around 125 
km causes significant upper mesosphere and 
thermosphere diurnal oscillations. Com¬ 
parison of the theoretical O/N 2 ratio with 



satellite measurements (Kohnlein et al, 
1975) show good agreement in amplitude 
and phase. Utilization of the photoelectron 
fluxes as well as the photon fluxes for ioniza¬ 
tion in the diumally varying chemical- 
transport model permits a reasonable calcu¬ 
lation of sunrise electron density distribu¬ 
tions, and predicts a daytime ionospheric 
“C” layer around 60 km. Varying the inten¬ 
sity of the lower thermosphere-mesosphere 
turbulent diffusion coefficient demonstrates 
that turbulence can cause significant varia¬ 
bility in the electron density distribution in 
the thermosphere. The theoretical diurnal 
behavior of N m (the amplitude of the F- 
layer peak electron density) compares quite 
well with that measured by incoherent 
scatter radar at Millstone Hill for the condi¬ 
tion that the turbulent diffusion coefficient 
is three times the minimum aiffusivity de¬ 
termined in the ALADDIN 1 Program. 

The analysis of the photographic records 
of the “through-the-night” series of chemi¬ 
cal trails in the ALADDIN 74 series at Wal¬ 
lops Island for the presence of turbulence 
and its intensity has been completed. The 
results show that from sunset to sunrise, 
the turbopause shows no altitude variabil¬ 
ity. However, the turbulent rate of dissipa¬ 
tion, determined from spectral analysis of 
the tracer density fluctuations, exhibits sig¬ 
nificant nighttime variations, with a mini¬ 
mum of intensity occurring in the post¬ 
midnight period. The values of the rates of 
dissipation determined range from 2x 10 1 
ergs/gm sec to 5x 10' ergs/gm sec. 


JOURNAL ARTICLES 
JULY 1976 • DECEMBER 1978 


Champion, K. S. W., and Forbes, J. M. 

(Boston Coll., Chestnut Hill, Mass.) 

Atmospheric Drag Analyses of Low-Altitude Doppler 
Beacon Satellites 

Proe. of Inti. Geod. Symp. on Satellite Doppler 
Positioning, Oct. 1976 (May 1977) 

Some Recent Mesospheric and Lower Thermospheric 
Data and Models 

Annales de Geophys., Vol. 34, No. 4 (1978) 

Champion, X. S. W., Marcos, F. A., and 

FORBES, J. M. (BostonColl., Chestnut Hill, Mass.) 
Lower Thermosphere Response to Geomagnetic 
Actirity 

Space Res. XVIII, Pergamon Press, N.Y. (1978) 

COHEN, H. A.,andMASEK,T. D. (HughesRes. 
Labs., Malibu, Calif.) 

Satellite Positiie-lon-Beam System 

J. of Spacecraft and Rockets. Vol 15. No. 1 (Jan. -Feb. 

1978) 

FORBES, J. M. (Boston Coll., Chestnut Hill. 
Mass.), and GARRETT, H. B. 

Solar Diurnal Tide in the Thermosphere 

J. of Atm. Sci., Vol. 33, No. 11 (November 1976) 

FORBES, J. M. (BostonColl.,Chestnut Hill. Mass.) 

and Garrett, H. B. 

Theoretical Studies of Atmospheric Tides 

Rev. of Geophys. Space Phys., Vol. 17. No. 8(1979) 

FORBES, J. M. (BostonColl., Chestnut Hill, 
Mass.), and MARCOS. F. A. 

Tidal Variations in Total Mass Density as Derired 
from the AE E MESA Experiment 
J. of Geophys. Res., Vo. 84, 1979 

FORBES, J. M. (BostonColl., Chestnut Hill, 
Mass.), Marcos, F. A., and Champion, K. S. 
W. 

Lower Thermosphere Response to Geomagnetic 
Actirity 

Space Res. XVIII, Vol. 18, Pergamon Press, N.Y. 
(1978) 

Gallagher, C. C., and Pieri, R. V. 

Stratospheric Measurements of.ViO, C EC It and 
CFJ'I, 

J. of Atm. Sci., Vol. 34, No. 9 (September 1977) 

GOLOMB, D., and BROWN, J. H. 

The Chemiluminescence of Trimethyl Aluminum in 
Actiie Oxygen and Sitrogen 
Combustion and Flame, Vol. 27 (1976) 


Champion, K. S. W., Dubin. M. <Nati. Aero, 
and Space Adm.), and HULL, A. R. (Natl. Oceanic 
and Atm. Adm., Boulder, Colo.) 

COESA 

U S. Std. Atm. (1976), U. S. Govt. Prtg. Off. 


Heroux, L. 

Applications of Beam-Foil Spectroscopy to the Solar 
Ultraviolet Emission Spectrum 
Bk., Beam-Foil Spectres., Pub. by Springer-Verlag, 
N.Y. (1976) 




33 


HEROUX, L., and HIGGINS, J. E. (West Coast 
Off., ElSeyundo, Calif.) 

Summary of Full-Disk Solar Fluxes Betueen JSOand 
!9iOA 

J. ofGeophys. Res., Vol. 82(Auyust 1977) 

HEROUX, L., and HlNTEREGGER, H. E. 
Aerouomical Reference Spectrum for Solar f V Below 
.’Ml A 

J. ofGeophvs. Res., Vol. 8)1, No. A 11(1 November 
1978) 

Higgins, J. E., and Heroux, L. 

Detenu imit ion of Mnlerti/arOxyyen Density [let oven 
! lib l'n Km tmm l+oilA Photometer 

J. ofGeophys. Res., Vol. 82(August 1977) 

HlNTEREGGER. H. E. 

FI T Fluxes in the Solar S/wctrii m Below loot) A 
J. of Atm. ami Torres. Phys., Vol. 38(197ti) 

FIT Flux Variations Danny Fad of SolarCycle Jo 
anilBeymninyCycle Jt.ttf. '.served trom AF-C Satellite 
Goophys. Res. Ltrs.. Vol. 4 (June 1977) 

HlNTEREGGER, H. E.. REDO, D. E., 

M ANSON. J. E.. andSKILLMAN, D. R. 
(Computer Usage Co.. Beltsville, MI)) 

FIT Flax Variations with Solar Rotation Obserreil 
Danny 1971 1970 trom the AF-C Satellite 
COSPAR Space Res., Vol XVII, Peryamon Press, 

N Y. (1977) 

HlNTEREGGER. H. E.. and CHAIKIN, L. M. 
(Computer Sciences Corp.. Silver Springs, MD) 

El T Absorption Analysis of Thermospheric 
Structure from AE• Satellite Observations of l97' 4 - 
iu:ti 

Spai*e Res. XVII, Pergamon Press, N.Y. (1977) 

Innks, F. R. 

AHioi nt ii re and Chases tor Spherical Functions and 
Operators 

Informationrur Kemforschuny und Kemtechnik, Pub. 
by Zentralstelle fur Atomkemeneryie-Dokumentation 
(ZAKD), W. Ger., Issue No. 5, Rpt. No. (All) 1779 
(1976) 

Katayama, D. H,,()gawa.S.,Ogawa, M. 

(Univ. ofSo. Calif., Lt-s Anyeles), andTANAKA, Y. 
(Univ. of Calif., Santa Barbara) 

The Varniim IT Absorption Spectrum of Ot from its 

Metastable Slates. b'TLg' and n‘±g 

J. ofChem. Phys., Vol. 67, No. 5(1 September 1977) 

Li nd, I. A., and Grantham, D. D. 

Persistence. Runs and Recurrence of Precipitation 
J. of Appl. Mel. (April 1977) 


Manson, J. E. 

The Solar S/iectrn m Between Jutland IJttllA 
The Solar Output and its Variation, Ed. by 0. R. 
White, Colo. Assoc. Univ. Press (1977) 

Marcos, F. A. 

Atmospheric Res/umse to Geomagnetic Activity 
Proc. ofSymp. at Bryce Mt., Va.,0ct. 1976 Vol. 2(July 
1977) 

Marcos, F. A., Champion, K. S. W., 
Potter, W. E., and Kayser, D. C. (Univ. of 
Minn.) 

Density and Ciimposition at the Sential Atmosphere 
at Ii<> Fin from Atmosphere Fxplorer-C Satellite Data 
Spate Res. XVII, Peryamon Qress, N.Y. (1977) 

Marcos, F A., GARETT, H.B., (SpacePhys. 
Div.i, Champion, K. S. W., and Forbes, J. 

M. (Boston Coll., Chestnut Hill. Mass, and Harvard 
Univ., Cambridge. Mass.) 

Density Variations in the Diner Thermosphere from 
.A nalysis of the AF-C Accelerometer Measu reaienh. 
Planetary and Space Sci., Vol. 25 (1977) 

Marcos, F. A., Philbrick, C. R., and 
Rice, C. J. 

(Aerosp. Corp., El Seyundo, Calif.) 

Correlative Satellite Measurements ot Atmospheric 
Mass Density by Accelerometers, Mass Spectrometers 
and Ionisation Ganges 

Spate Res. XVII, Peryamon Press, N.Y. (1977) 

Me Mahon, W. J., and Heroux, L. 

Rocket Measurement of Thermospheric Photoelectron 
Fnergy Spectra 

J. ofGeophys. Res., Vol. 83, No. A4(l April 1978) 

Moses, H. E. 

A Simple Proof of the Angular Momentum Helmholtz 
Theorem and the Relation of the Theorem to the 
Decomposition ofSolenoidal Vectors into Poloidal and 
Toroidal Components 

J. of Math. Phys., Vol. 17, No. 10(0ctober 197G) 

Murad, E., and Hildenbrand, D. L. 

(Stanford Res. Inst., Menlo Pk., Calif.) 
Thermochemical Properties of Gaseous EuO 
J. ofChem. Phys., Vol. 65(1976) 

NARCISI, R. S., and SWIDER, W. 

Ionic Struct it re Hear an Auroral A nr 
J.ofGeophys. Res., Vol. 81, No. 25< 1 September 1976) 

Paulson, J. F., and Gale, P. J. (YaieUniv , 

New Haven, Conn.) 

The Reaction of 0 with HsO 

Adv in Maas Spectrum., N. R. Daly, Ed., Heydenand 

Son, Ltd., London (1978) 


v 


t. 

% 



Philbrick, C. R. 

Recent Satellite Measurements of Upper Atmospheric 
Composition 

Space Res. XVI, Akademie-Verlag, Berlin(1976) 

Philbrick, C. R., Faucher, G., and 
Bench, P. 

Composition of the Mid-Latitude Winter Mesosphere 

and Lower Thermosphere 

Space Res. XVIII, Pergamon Press, N.Y. (1978) 

Philbrick, C. R., Me Isaac, J. P..and 
Faucher, G. A. 

Variations in Atmospheric Composition and Density 

During a Geomagnetic Storm 

Space Res. XVII, Pergamon Press, N.Y. (1977) 

Sherman, C. 

Orbit Classification for Spherical Probes 
The Phys. of Fluids, Vol. 19 (July 1976) 

Snyder, R. 

Magnetic Monopole and Charged Particle Ionization 
Cmss Sections 

Am. J. of Phys., Vol. 44, No. 12 (December 1976) 
SWIDER, W. 

Aemnomic As/wcts of the PolarD Region 
Space .>i. Rev., Vol. 20 (1977) 

Atmospheric FDonation of NO from N ■ f A'S. 
Geophys. Res. Ltrs, Vol. 3, No. 6 (June 1976) 

Daytime Nitnc Oxide at the Hase of the Thennosphere 
J. of Geophys. Res., Vol. 83, No. A9(1978) 

Minor Mesospheric C onstituents at High lsit dudes 
Space Res. XVII, Pergamon Press. N.Y. (1977) 

SWIDER, W., and CHIDSEY, I. L., JR. 

(U.S. Army Ballistic Res. Labs., Aberdeen Proving 
Ground, Md.) 

HF/VHF Absorption in the Disturbed D-Region 
J. of Geophys. Res., Vol. 82, No. 10(1 April 1977) 

SWIDER, W., KENESHEA, T. J., and FOLEY, 
C. I. (Boston Coll.) 

An SPE Disturbed D-Region Model 
Planetary and Space Sci., Vol. 26, No. 9 (1978) 

SWIDER, W., and NARCISI, R. S. 

Auroral E-Region: Ion Composition and NitricOride 
Planetary and Space Sci., Vol. 25, No. 2<February 
1977) 

Thomas, T. F., Dale, F., and Paulson, J. 
F. 

Photodissociation of Positive Ions. 1. Photo- 
dissociation Spectra ofDi', HD', and NiO* 

J. ofChem. Phys , Vol. 67(1977) 


Thomas, T. F., and Paulson, J. F. 

Photodissociation of Ion Beams in a Tandem Mass 
Spectrometer Using a Tunable Dye Laser 
Proc. of 24th Ann. Conf. on Mass Spectrom. and Allied 
Topics (November 1976) 

Photodissociation Spectra of Positive Ions 
Natl. Bur. ofStds. Sp. Pub. 526 (October 1978) 

Thomas, T. F., Rose, T. L., Welsh, J. A., 
and Paulson, J. F. 

Photofragment Spectroscopy of NeO ' 

Proc. of 25th Ann. Conf. on Mass Spectrom. and Allied 
Topics (1977) 

TRINKS, H. (Univ. ofWuppertal, Fed. Rep. of 
Ger.), MaYR, H. G. (NASA Goddard Space Flight 
Ctr., Greenbelt, Md ), and PHILBRICK, C. R. 
Momentum Source Signatures in Thermospheric 
Neutral C omposition 

J. of Geophys. Res., Vol. 83, No. A4 (April 1978) 

Weeks, L. H„ Good, R. E., Randhawa, 

J. S. (U. S. Army Atm. Sci. Lab., White Sands Missile 
Range, N. M.), and THINKS, H. (Phys. Inst, der 
Univ., Bonn, Fed. Rep. of Ger.) 

Ozone Measu rements in the Stratosphere, Mesosphere, 
and Lower Thermosphere During ALADDIN 'I 
J. of Geophys. Res., Vol. 83 (1 March 1978) 

YOSHINO, K., and OGAWA, M., TANAKA, Y. 
Extension of Rydberg Absorption Series of N «, A*irn«- 

.vir 

J. of Mol. Spectres., Vol. 61(1976) 

Zimmerman, S. P. 

Turbulence Observed in Electron Density 
Fluctuations in the Equatorial E Region Over 
Thumba, India - A Reanalysis 
J. of Geophys. Res., Vol. 81(1976) 

Zimmerman, S. P., and Keneshea, T. J. 

The Thermosphere in Motion 
J. of Geophys. Res., Vol. 81 (1976) 

Zimmerman, S. P., and Murphy, E. A. 

“Stratospheric and Mesospheric Turbulence" section in 
Dynamical and Chemical Coupling by the Neutral 
and Ionized Atmosphere 
Ed. by B. Grande! and T. A. Holtel, 

D. Reidel Pub. Co., Holland (1977) 

Fine Scale Dynamics of the Middle Atmosphere 
Free, of Jt. Assbly., IAGA/IAMAP, Aug. 1974 
(November 1977) 




35 


Zimmerman, S. P., Quesada, A. F., 
Good, R, E., and Trowbridge, C. A. 

(Photomet., Inc., Lexington, Mass,), OLSEN, R. 0. 
(U. S, Amy Atm, Sci. Lab,, White Sands Missile 
Range, N.M.) 

Mesospheric Dynamics Measured During the 1976 

"Winter Anomaly" Campaign 

Space Res. XVIII, Pergamon Press, N.Y. (1978) 


PAPERS PRESENTED AT MEETINGS 
JULY 1976 - DECEMBER 1978 

Champion, K. S. W. 

Some Inputs for Improved l ’pper Atmosphere Models 
Atm. Explorer Symp., Bryce Mt., Va. (October 1070) 
Mesospheric and Thermospheric Properties and 
Models 

Atm. Explorer Symp. II, Bayse, Va, (1-6 October 
1978) 

Champion, K. S. W., and Forbes, J. M. 

(Boston Coll., Chestnut Hill, Mass.) 

Atmospheric Drag Analyses of Uni-Altitude Doppler 
Heacon Satellites 

Inti. Geod. Symp., Las Cruces, N.M. (October 1976) 
Some Recent Mesospheric and l.nu'er Thermospheric 
Data and Models 

21st Comm, on Space Res. (COSPAR)Symp., 
Innsbruck, Aus. (29 May - 10 June 1978) 

Champion, K. S. W., Marcos, F. A., and 
FORBES, N. M. (Boston Coll., Chestnut Hill, 
Mass.) 

Lower Thermosphere Response to Geomagnetic 
Activity 

20th Comm, on Space Res. (COSPAR) Symp., Tel- 
Aviv, Isr. (7-1H June 1977) 

Dewan, E. 

Stratospheric Dynamics and the Ozone Pollution 
Problem 

Atm. Sci. Res. Ctr., State Univ. of N.Y. at Albany, 
N.Y. (7 February 1977) 

Extensions of Kolinogoroe's Theory o/ Tu rbulence 
Spectra to Stratified Fluids 
Phye. Dept., Boston Coll., Chestnut Hill, Mass. (20 
April 1977) 

Eddy Diffusirity and Stratospheric Spectra of 
Turbulence Mixed with Wares 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

The S’at u re of Stratospheric Tu rbulence a nd 
Implications Regarding Pollution 
Dept, of Atm. Sci., State Univ. of N.Y. at Albany, 
N.Y. (8 May 1978) 


Stratospkeric Turbulence Spectra and the Dissipation 
Rate and Diffusirity Measurements 
Am. Geophys. Union Spring 1977 Mtg., Wash., D.C. 
(30 May-3 June 1977) 

FORBES, J. M. (BostonColl., Chestnut Hill, 

Mass ), Marcos, F. A., and Champion, K. S. 
W. 

Loner Thermosphere Response to Geomagnetic 
Activity 

Comm, on Space Res. (COSPAR) Symp., Tel Aviv, 
Isr. (7-18 June 1977) 

Gallagher, C., et al 

Stratospheric Trace Gas Studies Vsinga Balloon- 
Borne, Cryogenic, Whole Air Sampler 
The Wentworth-By-The-Sea, Portsmouth, N.H. (21- 
23 August 1978) 

Good, R. E., and Brown, J. H. 

Stratospheric Turbulence as Measured with a Corona 
Anemometer 

Am. Geophys. Union Spring 1977 Mtg., Wash., D.C. 
(30 May -3 June 1977) 

Stratospheric Small Scale Turbulence 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 

Fla. (17-21 April 1978) 

Good, R. E., Brown, J. H., Quesada, A. 
F., and Trowbridge, C. A. (Photomet., Inc., 
Lexington, Mass.) 

Coordinated Balloon and Rocket Measurements of 
Stratospheric Wind Shears and Turbulence 
1978 Comm, on Space Res. (COSPAR) Mtg., 
Innsbruck, Aus. (29 May -10 June 1978) 

HEROUX, L., and HlNTEREGGER, H. E. 
Aenmomical Reference Spectrum of Solar EUV 
1978 Comm, on Space Res. (COSPAR) Mtg., 
Innsbruck, Aus. (29 May - 10 June 1978) 

Katayama, D. H. 

Photodissociation Cross Sections of Ar,' for the ’£<;*«- 
X'hi' Transition 

Chem. Dyn. Mtg., AFGeophys. Lab., Hanscom AFB, 
Mass. <26-27 October 1977) 

Isotope Shifts for the Huggins Bands of Ozone 
Mol. Spectres. Symp., Ohio State Univ., Columbus, 
Ohio (12-16 June 1978) 

Katayama, D. H., Paulson, J. F., and 
Rose, T. L. 

Photodissociation Cross Sections in Art'for the £-£ 
Transition 

30th Ann. Gaseous Elect. Conf., Palo Alto, Calif. (18-21 
October 1977) 

Vibrational Population and Mechanism for 
Formation of Art' in an Electron Impact Ion Source 
26th Ann. Conf. on Mass Spectrom. and Allied Topics, 
St. Louis, Mo. (28 May - 2 June 1978) 







36 


Marcos, F.A. 

Atmospheric Response to Geomagnetic Activity 
Atm. ExplorerSymp., RryoeMt., Bayse, Va. (October 
1970) 

Murad, E. 

The Dissociation Energy of Gaseous Praeseiulymiiim 
Monoxide 

1:17th Mtg of Am. Chem Soc., New Orleans, l-a. (20-25 
March 1977) 

The Dissociation Energy ofNeiulyinium Monoxide 
25th Ann. Conf. on Mass. Spectrom. and Allied Topics, 
Wash., D. C. (29 May - 3 June 1977) 

The Dissociation Energies of Some Metal Oxides 
Chem. Dyn. Conf., AFGeophys. I,ab., Hanscom AEB, 
Mass. (20-27 October 1977) 

Chemistry at Metal Ions in the Ionosphere 
NATO Adv. Study Inst, on Kinetics of lon-Mol. 
Reactions, LaBaule, Kr. (5-15 September 1978) 

Murad, E., and Michael, I. 

Mass Sfiectrinnetnc Measurement of the Dissociation 
Energy of Gaseous Gadolinium Monoxide 
175th Natl. Mtg. of Am. Chem. Soc., Anaheim, Calif. 
(12-17 March 1978) 

The Dissociation Energy of Selenium Monoxide 
26th Ann. Conf. on Mass Spectrum, and Allied Topics, 
St. Louis, Mo. (28 May - 2 June 1978) 

Murphy, E. A., and Zimmerman, S. P. 

A Description of Turbulence in the Troposphere and 
Stratosphere 

1978 Spring Am. Geophys. Union Mtg., Miami Reach, 
Fla. (17-21 April 1978) 

Narcisi, R. S. 

The Stratospheric Research Program and Ionospheric 
Com/nisition Research at the Air Force Geophysics 
Ixtbondory 

Sem., Princeton Univ., Princeton, N.J. OK) March 
1977) 

Paulson, J. F. 

C ollisional Dissociation ofNOt and of Some Sol rated 
Hydroxyl Ions 

:10th Ann. Gaseous Elect. Conf., Palo Alto, Calif. (18-21 
October 1977) 

Ion Chemistry at AEGI. 

AKOSR/AFGLChem. Dyn. Conf., AFGeophys. Lab., 
Hanscom AFB, Mass. (26-27 October 1977) 

Snatching Reactions of Solvated Hydroxyl Ions 
31st Ann. Gaseous Elect. Conf., Buffalo, N.Y. (17-20 
October 1978) 

Paulson, J. F., and Gale, P. J.tYaieUniv., 
New Haven, Conn ) 

The Reaction of O uhth HtO 

7th Inti. Mass Spectrom, Conf., Florence, Italy (29-31 

August 1976) 


Collisional Dissociation gfCOt 

29th Ann. Gaseous Elect. Conf., Cleveland, Ohio (1922 

October 1976) 

PHILBRICK, C. R.. FaUCHER, G., and 
Bench, P. 

Composition of the Mid-lMtitude Winter Mesosphere 
and Tower Thermosphere 

Comm, on Space Res. (COSPAR) Mtg., Tel Aviv, Isr. 
(7-18 June 1977) 

Philbrick, C. R., Faucher, G. A., 

TRZCINSKI, E., and BENCH, P. 

Neutral Composition of the Mesosphere and lAimer 
Thermosphere 

Am. Geophys. Union Spring 1977 Mtg., Wash., D.C. 
(30 May -3 June 1977) 

Rose, T. L. 

Photmlissociation of Polyatomic Positive Ions 
AFOSR/AFGLChem. Dyn. Conf., AFGeophys. Lab. 
(26-27 October 1977) 

Photodissociation of Simple Ions 

U. S. Army Ballistic Rea. Lab., Aberdeen Proving 

Ground, Md. (13 December 1977) 

Rose, T. L., and Buckley, G. S. 

(Dept, of Chem., Texas A & M Univ.) 

Reactions of "Yhde" Intennedmte Produced in Gas 
Phase Reactions of Methylene Hath Acetone 
175th Am. Chem. Soc. Natl. Mtg., Anaheim, Calif. 

(12-17 March 1978) 

Rose, T. L., Katayama, D., and Paulson, 

J. F. 

Photodissociation of Net)’ In Crossed Ixiser-lon Beam 
Experiments 

Laser Induced Chem. Symp., 175th Natl. Mtg. of Am. 
Chem. Soc., Anaheim, Calif. (12-17 March 1978) 

Russak, S. L., Flemming, J. C. (Martin 
MariettaCorp., Denver, Colo.), HUFFMAN, R. E., 

Paulsen, D. E. t and Larrabee, J. C. 

Development of Proximity and Electrostatically 
Focused Digicoms for UV Measurements from 
Sounding Rockets 

7th Symp. on Photoelec. Image Device*. Imperial 
Coll., London, Eng. (4 September 1978) 

SWIDER, W. 

Nitric Oride in the Ixmer Thermosphere and Upper 
Mesosphere 

Inti. Assoc, of Geomag. and Aeron., Seattle, Wash. (22 
August - 3 September 1977) 

Processes Determining the Height Distributions of 
Metallic Ions 

Inv. Paper. Inti. Assoc, of Geomag. and Aeron., 
Seattle, Wash. (22 August - 3 September 1977) 



37 


SWIDER, W., and FOLEY, C. I. (Boston Coll., 
Chestnut Hill, Mass.) 

The Influence of Minor Atmospheric Constituents on 
the Electron Loss Rates of the August i-tt, 1971 and 
November 3-5, 1969, Solar Proton Events 
Am. Geophys. Union Spring Mtg., Wash., D.C. (20 
May -3 June 1977) 

Swider, W., Foley, C. I., and Keneshea, 

T. J. (Boston Coll., Chestnut Hill, Mass.) 

Twilight E-Region Enhancements as a Result of 
A ii rorallg Iitcrraseil Nitric Oxide Concentrations 
Am. Geophys. Union Eall Mtg., San Francisco, Calif. 
(6-10 December 1976) 

Swider, W., Keneshea, T. N.,and Foley, 

C. (Space Data Lab., Boston Coll., Chestnut Hill, 
Mass.) 

D-Region Model fir a Solar Proton Event 

1978 Spring Am. Geophys. Union Mtg., Miami, Fla. 

<17-21 April 1978) 

Depletion of Mesospheric 02one at Sunrise 

1978 Fall Am. Geophys. Union Mtg., San Francisco, 

Calif. (4-8 December 1978) 

Thomas, T. F., Rose, T. L., Welsh, J. A., 
and Paulson, J. F. 

Photofragment S/tectmscopy ofNtfl' 

25th Ann. Conf. on Mass Spectnom. and Allied Topics, 
Wash.. D. C. (19May -3 June 1977) 

Zimmerman, S. P., and Keneshea, T. J. 

Thermospheric and Ionospheric Distributions and 
Structure as Influenced by the Variations of 
Turbulence 

Am. Met. Soc., Boston, Mass. (23-26 October 1978) 

Zimmerman, S. P., and Murphy, E. A. 

Stratospheric and Mesospheric Turbulence 
NATO Adv. Study Inst., Nord Torpa, Norway (12-22 
April 1977) 

Fine Scale Dynamics of the Middle Atmosphere 
Jt. IAGA/IAMAP Assby., Seattle, Wash. (22 August - 
3 September 1977) 

Microscale Dynamical Structure of the Troposphere 
and Stratosphere 

Am. Met. Soc., Boston, Mass. (23-26October 1978) 

Zimmerman, S. P., Quesada, A. F., 
Good, R. E., Trowbridge, C. A.fPhotomet., 
Inc., Lexington, Mass.), and OLSEN, R. 0. (Army 
Atm. Sci. Lab., White Sands Missile Range, N. M.) 
Mesospheric Dynamics Measured During the 1976 
Winter A nomaly Campaign 
Comm, on Space Res. (COSPAR) Wkg. Gp. IV, Tel 
Aviv, Isr. (13-18June 1977) 


TECHNICAL REPORTS 
JULY 1976 - DECEMBER 1978 

Bailey, A. D. 

E.XCEDEISWIR Ion Mass Spectrometer An 
Instruinent Description 
A FGL-TR 78-0010 (6 January 1978) 

Dewan. E. M. 

Theoretical Explanation of S/iectral Slo/ies in 
Stratospheric Turbulence Data a ltd Implications tor 
Vertical Transport 
AFGL TR 76-0247 (18 October 1976) 

Forbes, J. M. (Boston Coll., Chestnut Hill, 

Mass ), Marcos, F. A., Gillette, D. F. 

An Evaluation at Thermospheric Models 
AFGL-TR-78-0140 (July 1978) 

Gallagher, C. C.. andPIERI, R. V., 

(’APT. 

Cryogenic, Whole-Air Sampler and Program for 
Stratospheric Composition Studies 
AFGL-TR-76-0161 (20 July 1976) 

Goon, R. E., Brown, J. H.,and 
Harpell, G. 

Development oI a Corona Anemometer for 
Measurement ot Stratospheric Turbulence 
AFGL-TR-78-0070 (21 March 1978) 

Good, R. E., Forsberg, C. A., and Bench, 
P. M. 

Breakup Characteristics at JP-i Vented From KC-U6 
Airrnitt 

AFGL TR 78-0190 (8 August 1978) 

Marcos, F. A., and Fioretti, R. W. irdp, 

Inc., Waltham. Mass.) 

Orbital Bias Determination tor Accelerometers on 
Atmosphere Explorer Satellites 
AFGL TR 77-0147 (5July 1977) 

Marcos, F. A., Me Inerney, R. E., and 
Fioretti, R. W. IRDP, Inc., Waltham, Mass.) 
Variability ot the Lower Thermosphere Determined 
tram Sab I life Accelerometer Data 
AFGL-TR-78-0134 (25 May 1978) 

Me Isaac, J. P., Me Inerney, R. E., and 

DELOREY, (BostonColl., Chestnut Hill, Mass.) 
Satellite Ionization Gauge Measurements ot 
Atmospheric Density 
AFGL-TR-78-020K15 August 1978) 

Me Mahon, W. J., and Heroux, L. 

Rocket Measurement ot the Energy Distribution and 
Flux of Thermospheric Photoelectrons 
AFGL-TR-77-0013( 13 January 1977) 



Mi’rad, E. 

Thermochemical and Kinetic Data at Gaseous MetaI 
Oxides and Their Relationship to Atmospheric 
Composition 

AFGL-TR-77-0235 (26 October 1977) 

Ml'rad, E., and Tanaka, Y. 

Molecular Studies ot Gaseous Oxides 
AFGL-TR-76-0213 (20 September 1976) 

P.U'LSEN, I). E., and HUFFMAN, R. E. 
Nitrogen Dioxide Ahsori>tion Coetticients at High 
Tem/teratu res 

AFGL-TR-76-0240 (5 October 1976) 

PHILBRICK, C. R.. FaIRF., A. C.. and 
FRYKLI'ND, D. H. (AccumetricsCorp., 
Cambridge, Mass.) 

Measurements at Atmospheric Density at Kiivjalcin 
Atoll, Id Mag 1977 
AFGL-TR-78-0058 (30 January 1976) 

Philbrick, C. R., Noonan, J. P. <rdp, 
inc), Fletcher, E.T., Jr., Hanrahan.T. 

(Xonics, Inc., Los Angeles, Calif.) SALAH, J. E., 
Blood, D. W. (MIT Lincoln Lab, Lexington, 

Mass ), Olsen, R. 0., and Kennedy, B. W. 

(Army Atm. Sci. Lab., White Sands Missile Range, 

N. M.) 

Atmospheric Properties from Measurements at 
Kwajalein Atoll on S April 197X 
AFGL-TR-78-0195(11 August 1978) 

QUESADA, A. F., and TROWBRIDGE, C. A. 
(Panamet., Inc., Lexington, Mass.) 

Analysis of Smoke Trail Photographs to Determine 
Stratospheric Winds and Shears 
AFGL-TR 76-0243 (8 October 1976) 

Sherman, C. 

A Method for Treating the Sheath Size in the Langmuir 
Mott-Smith Equations 
AFGL-TR-78-0138(2 June 1978) 

SWIDER, W. 

Ionic Reactions Deduced from Atmosphere Explorer 
Data: A Survey 

A FG L-TR-78-0274 (13 November 1978) 

“Auroral NO” in Proc. HAES Infrared Data Review, 
Vol. II, 

AFGL-OP-TM-05(June 1977) 

SWIDER, W., and BENCH, P. M. 

Impact of F 16 and KC-10A Emissions Upon 
Stratospheric Ozone 
AFGL-TR-78-0198 (8 Agust 1978) 

SWIDER, W., and FOLEY, C. I. (BostonColl., 
Chestnut Hill, Mass.) 

Steady-State Multi-Ion Disturbed D-Region Model 
AFGL-TR-78-0155 (15 June 1978) 


SWIDER, W., KENESHEA, T. J., and FOLEY, 
C. I. (Boszon Coll., Chestnut Hill, Mass.) 

Sunrise E-Region Enhancements from Aurorally 
Increased NO: Theory 
AFGL-TR-77-0204 (15 September 1977) 

Van Tassel, R. A. 

Airglow Calculations for Remote Sensing of Density 
AFGL-TR-78-0115 (5 May 1978) 

Zimmerman, S. P., and Keneshea, T. J. 

Dissociation Driven Diurnal Oscillations 
AFGL-TR-78-0139 (30 May 1978) 


CONTRACTOR JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 

FORBES, J. M. (Boston Coll.,Chestnut Hill, Mass.) 
Empirically Modelling the fsiwer Thermosphere 
Proc. ofSymp. at Bryce Mt., Va., Oct. 1976, Vol. 2 
(July 1977) 

Tidal Variations in Thermospheric 0, Ot, N i, Ar, He, 
and H. 

J. ofGeophys. Res., Vol. 83 (August 1978) 

MASEK, T. D., (Hughes Res. Labs., Malibu, 
Calif.), and Cohen, H. A. 

Satellite Positive Ion Beam System 

Proc. of AIAA Inti. Elec. Propulsion Conf., Key 

Biscayne, Fla. (14-17 November 1976) 


CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 • DECEMBER 1978 

Best, G. T., and Kitrosser, D. F. 

(University of Lowell, Lowell, Mass.) 

Computer Code Sensitivity Study of Photoionization - 
Detachment and Dissociation at D-Layer Altitudes in 
Twilight 

AFGL-TR-78-0272 (November 1978) 

BlEN, F, (Aerodyne Res., Inc., Bedford, Mass.) 
Measurements of Nitric Oxide Ion Vibrational 
Absorption Coefficient and Vibrational Transfer to Nt 
AFGL-TR-77-018I (15 August 1977) 

BUCKLEY, J. L. (Ball Bros. Res. Corp., Boulder, 
Colo.) 

Solar EUV Spectrophotometer for Atmosphere 
Explorer 

AFGL-TR- /6-0202 (August 1976) 

CATANEO, R. (University of Ill., Urbana, Ill.) 
Linear Precipitation Characteristics in the 
Atmosphere 

AFGL-TR-76-0094 (December 1976) 



39 


ClESIELSKI, T. E., and DULCHINOS, J. 
(Epsilon Labs., Inc., Bedford, Mass.) 

Satellite Density Gauge Instrumentation Program 
AFGL-TR-76-0271 (October 1976) 

CRANE, R. K. (Envmt. Res. andTechnol., Inc., 
Concord, Mass.) 

Stratospheric Turbulence Analysis 
AFGL-TR-77-0207 (September 1977) 

DURGIN, F. H., and FANUCCI, J. P. (Mass. 
Inst, ofTechnol., Cambridge, Mass.) 

Static anti Dynamic Calibration of a Corona 
Discharge Anemometer 
AFGL-TR 77-0022 (December 1976) 

Fite, W. L., and Hsi Hu Launiv. of 
Pittsburgh, Pa.) 

Reactions of UO * with Atmospheric Gases 
AFGL-TR-77-0029 (January 1977) 

Fite, W. L., Patterson, T. A., and 
SlEGEL, M. W. (Extranuc. Labs., Inc., Pittsburgh, 
Pa.) 

Cross Sections for Thermal Reactions Between 
Uranium Atoms and Atmospheric Species 
AFGL-TR-77-0030 (December 1976) 

FORBES, J. M. (BostonColl., Chestnut Hill, Mass.) 
Upper Atmosphere Density Data and Models 
AFGL-TR-78-0296 (31 October 1978) 

FORBES, J. M. (BostonColl., Chestnut Hill, 
Mass.), and GARRETT, H. B. (Space Phys. Div.) 

A FORTRAN Program for Solring Systems of 
Coupled Second-Older Differential Equations with 
Two-Point Boundary Cond lions 
A FG L-TR-76-0205 (1 August 1976) 

FRYKLUND, D. H. (Accumet. Corp., Cambridge, 
Mass.) 

Applied Research and Development on Triarial 
Piezoelectric (PZLl Accelerometer Systems of 
lmproved Design 
AFGL-TR-77-0187 (August 1977) 

GROVES, G. V. (Univ. Coll, of London, Eng.) 
Determination of Air Density, Temperature and 
Winds at High Altitude 
AFGL-TR-77-0068 (31 January 1977) 

HALDEMAN, C. W., KrAEMER, R. A., and 
ZlPH, B. (Mass. Inst. ofTechnol., Cambridge, 
Mass.) 

Wind Tunnel Tests of the Upstream Influence of a 
Con ical Mass Spectrometer Probe 
AFGL-TR-77-0210 (September 1977) 

HANSER, F. A,, and SELLERS, B. (Panamet, 
Inc, Waltham, Mass.) 

A nalysis of Ground Station Magnetometer Data 
Obtained During the Rocket Launches in the AEOLUS 
Program, April 1975, at Ft. Churchill, Manitoba 
AFGL-TR-77-0043 (December 1976) 


HILLS, R. S. (TRI-CON Assoc., Inc., Cambridge, 

Mass.) 

Electronic Subsystem for Normal I ncidence 
Ultra motet Spectrometer 
AFGL-TR-76-0206 (September 1976) 

HUBLR, W. B. (TRI-CON Assoc., Inc., 
Cambridge, Mass.) 

Design and Fabrication of Satellite Electron Beam 
System 

AFGL-TR-76-0184 (1 August 1976) 

Design, Fabricate and Test Instrumentation For 
Rocketbome Meant remen ts of Veh icle Charging 
AFGL-TR-78-0164(19June 1978) 

Post Flight Evaluation of Electronic Circuitry 
Performance 

AFGL-TR-76-0169(30June 1976) 

Isaacs, R. G., Burke, H.-H. K., Tripp, 

N., and DAK SZE, N. (Envmtl. Res. andTechnol., 
Inc., Concord, Mass.) 

Development of the Radiative Transfer Portion of a 
l-D Photochemical Diffusive Stratospheric Model 
AFGL-TR-77-0293 (March 1978) 

LANGE, W. G. (Bell Aerosp. Textron, Buffalo, 
N.Y.) 

Accelerometer System for S77-2 Satellite 
AFGL-TR-77-0179(30June 1977) 

Development, Test, and Calibration of a Three-Aris 
Accelerometer System 
AFGL-TR-78-0003 (December 1977) 

Larson, L. J. (HYCOR, Inc., Woburn, Mass.) 
High Altitude Smoke Program I HASP) 
AFGL-TR-78-0147 (31 May 1978) 

Martin, D. E. (St. Louis Univ., Mo.) 

Research to Develop Improved Models of Climatology 
that Will Assist the Meteorologist in the Timely 
Operation of the Air Force Weather Detachments 
AFGL-TR-76-0249 (31 August 1976) 

MASEK, T. (Hughes Aircraft Co., Res. Lab. Div., 
Malibu, Calif.) 

Rocket Model Satellite Positive Ion Beam System 
AFGL-TR-78-0179 (1 July 1978) 

Satellite Positive Ion Beam System 
AFGL-TR-78-0141O June 1978) 

MASEK, T. D. (Hughes Res. Labs., Malibu, Calif.), 
and COHEN, H. A. (Aeron. Div , AFGL) 

Satellite Positive Ion Beam System 
AFGL-TR-77-0241 

Me DONALD, M. (Wentworth Inst. ofTechnol., 
Boston, Mass.) 

Design and Fabrication of Compact Portable Vacuum 
Systems for Field Use 
AFGL-TR-77-0250 (31 August 1975) 

Design and Fabrication of Transport Spheres for High 
Vacuum Use 

AFGL-TR-77-0307 (31 August 1976) 





40 


MC GRATH, J. F., and PADUR, J. P. (Comstock 
& Wescott, Inc., Cambridge, Mass.) 

Double-Deck Solar Extreme Ultminolet Spectrometers 
AFGL TR-76-0160 (31 July 1976) 

Modification of Solar EUV Spectrometer RM-60 
AFGL-TR-77dl45(31 July 1977) 

MELDRUM, M. M., and LANGE, W. G. (Bell 
Aerosp. Textron, Buffalo, N.Y.) 

Analytical Study to Measure Solar Radiation 
Pressure on NTS-.i Satellite Using Mesa 
Accelerometer 

AFGL-TR-77-0215 (31 August 1977) 

MERRITT, M. J. (Met. Res., Inc., Altadena, Calif.) 
Fuel Dump Plume Characterization 
AFGL-TR-77-0085(I)( 18 March 1977) 

Michael, S. B., Morris, J. S., and 

PHILBRICK, 0. (Inf. Design, Inc., Civil Air 
Terminal, Bedford, Mass.) 

Analysis of Chemical Smoke Releases to Characterize 
StratospherielThermospheric Wind Fields 
AFGL-TR-77-0007 (November 1976) 

MlCHELS, H. H. (United Technol. Res. Ctr., East 
Hartford, Conn.) 

Air Molecular Camputation Study 
AFGL-TR-77-0032 (30 March 1977) 

MOLTER, 0. E. (Wentworth Inst., Boston, Mass.) 
Technigues and Matching Processes Used in the 
Manu'.icture of Components for High Attitude Mass 
Spectrometers 

AFGL-TR-77-0196 <31 August 1977) 

Murphy, G. P. (Tricon Assoc., inc., 

Cambridge, Mass.) 

The Design Development and Test of Satellite, Balloon 
and Rocket Borne Mass Spectrometer, Electronic 

A 9 ft tent hi IPS 

AFGL-TR-76-0214 (September 1976) 

OTIS, J. M. (Wentworth Inst. ofTechnol., Boston, 
Mass.) 

Atmospheric Composition Instruments 
AFGL-TR-78-0012 (26 December 1977) 

PADUR, J. P. (Comstock & Wescott, Inc., 
Cambridge, Maas.) 

Double Normal-Incidence Ultraviolet Grating 
Spectrometer 

AFGL-TR-77-0273 (November 1977) 

Normal-Incidence Extreme Ultraviolet Grating 
Spectrometer 

AFGL-TR-76-0171 (31 July 1976) 

Rochefort, J. S., and Sukys, R. 

(Northeastern Univ., Boston, Mass.) 

A Digital Control Unit fora Rocket Borne Quadrupole 
Mass Spectrometer 
AFGL-TR-78-0106 (April 1978) 

Electronics fora Rocket-Borne Quadrupole Cluster 
Ion Mass Filter 

AFGL-TR-78-0292 (October 1978) 


Instrumentation Systems for Mass Spectrometers 
AFGL-TR-76-0200 (September 1976) 

Roper, R. G., and Edwards, H. D. (Georgia 

Institute ofTechnol., Atlanta, Ga.) 

A Comparison Between Ground Based and Aircraft 
Triangulation of Chemical Releases in the Lower 
Thermosphere 

AFGL-TR-77-0089 (April 1977) 

Upper Atmosphere Chemical Release and Smoke Trail 
Triangulation, 1974-1977 
AFGL-TR-77-0161 (July 1977) 

SLOWEY, J. W. (TrusteesofBostonColl.,Chestnut 
Hill, Mass.) 

Reduction in the Number of Terms in Geopotential 
Models Used in Satellite Orbit and Ephemeris 
Computation 

AFGL-TR-77-0158G August 1977) 

Sluder, R. B., and Kofsky, I. L. (PhotoMet, 
Inc., Lexington, Mass.) 

Photographic Measurements of Electrical Discharges 
AFGL-TR-78-0082 (31 March 1978) 

Smith, D. (Univ. of Birmingham, Eng.) 

Binary Positive lon-Negatiiv Ion Mutual 
Neutralization Reactions 
AFGL-TR-78-0162 (31 May 1978) 

Smith, F. T., and Hickman, A. P. (Stanford 
Res. Inst., Menlo Pk., Calif.) 

Ini’estigation of Ion-Ion Recombination C mss 
Sections 

AFGL-TR-77-0055( 18 February 1977) 

Stokes, C. S.. Murphy, W. J., and 

MURPHY, E. W. (Germantown Labs., 
Philadelphia, Pa.) 

Chemical Release Payloads for Stratospheric Wind 
Measurements I977-I97S and Related Programs 
AFGL-TR-78-0307 (30 October 1978) 

Stokes, C. S., Murphy, W. J., and Smith, 

E. W. (Germantown Labs., Inc., Philadelphia, Pa.) 
Chemical Release Payloads for the Winter Anomaly 
Program ( 1976), ICE CAP Program < 1976) and 
Operation H ARSES ( 1976) 

AFGL-TR-76-0312 (30 October 1976) 

SUGIMURA, T. (TRW Sys. Gp„ Redondo Beach, 
Calif.) 

Monte Carlo Simulation of Ion Collection by a Rocket- 
Borne Mass Spectrometer 
AFGL-TR-77-0027 (January 1977) 

Monte Carlo Simulation of Negative Ion Collection by 
a Rocket-Borne Mass Spectrometer 
AFGL-TR-78-0094 (March 1978) 

TIMOTHY, J. G. (Harvard Coll. Obsv. and 
Smithsonian Astrophys. Obsv., Cambridge, Mass.) 

The Development and Test of Sealed Multi-Anode 
Detectors Based on MicroChannel Array Plates for Use 
at Ultraviolet Wavelengths 
AFGL-TR-77-0084 (February 1977) 


r 



sr 



41 


Trowbridge, C. A. (PhotoMet., inc., 
Lexington, Mass.) 

Densitometric Analyses to Determine Artificial Cloud 
Expansion Characteristics 
AFGL-TR-78-0075 (15 March 1978) 

Trowbridge, C. A., and Andrus, W. S. 

(PhotoMet., Inc., Lexington, Mass.) 

An Automated Coordinate Measurement System for 
Smoke Trail Photographs 
AFGL-TR-78-0231 (29 September 1978) 


Trowbridge. C. A., Kofsky, I. L., and 

JOHNSON, R. tt. (PhotoMet., Inc., Lexington,. 
Mass.) 

Recording and Analysis of Optical Data from 
Stratospheric Dynamics Experiments 
AFGL-TR-78-0015 (14 January 1978) 

Wilcox, R. W., Nastrom, G. D., and 

BrOWW, D. E. (Control Data Corp., Minneapolis, 
Minn.) 

Studies of Stratospheric Eddy Transport 
AFGL-TR-78-0311 



42 



Aries Vehicle at WSMR 


Ill AEROSPACE INSTRUMENTATION 
DIVISION 


The Aerospace Instrumentation Division 
has the special responsibility of providing 
AFGL experimenters with the rocket, 
satellite, and balloon platforms they need to 
conduct their experiments. For many 
years, AFGL’s balloon branches were also 
called upon to assist the Army, the Navy, 
NASA, and othqr government agencies who 
found balloon-borne experiments the most 
effective way to obtain their data. The 
Sounding Rocket Branch, which had in the 
past served AFGL experimenters exclu¬ 
sively, was given missions supporting the 
Space and Missile Systems Organization, 
and the Defense Nuclear Agency. A re¬ 
search and development program, although 
limited during this reporting period by re¬ 
ductions in funds as well as personnel, is also 
carried on to help insure that the most 
current, reliable and cost effective tech¬ 
nology is available to the scientists and 
engineers of using organizations. To ac¬ 
complish this mission, the Division’s man¬ 
ning consists mainly of engineers and tech¬ 
nicians, both military and civilian. 

During this reporting period, 18 sounding 
rockets were flown. Nine of these were 
launched from White Sands Missile Range, 
New Mexico. Five were launched from 
Kwajalein Missile Range, Micronesia Trust 
Territory, two from Poker Flat Research 
Range, Alaska, and two from NASA 
Wallops Flight Center, Virginia. 

The Division operates and mans a per¬ 
manent balloon launch facility at Holloman 
AFB, New Mexico. This function includes a 
permanently equipped and maintained 
tethered balloon facility located in the 
northern section (Fair Site) of the White 
Sands Missile Range. 





44 


RESEARCH ROCKETS 

The Sounding Rocket Branch of the 
Division is responsible for management of 
rocket-payload systems, payload engineer¬ 
ing, fabrication, test, launch support, data 
acquisition and trajectory information. 

The Division also provides engineering 
management of the sensor-satellite inter¬ 
face for those satellites on which AFGL 
scientists are oroviding sensors for scien¬ 
tific investigation. This involves interface 
management starting with design and fol- 



A Hi Hi Star Launch. 

lowing through the fabrication, testing and 
pre-launch phases. During this reporting 
period, the Division, working with the 
Space Physics Division, began the design of 
its first Space Shuttle experiment package. 
Engineering research is also conducted in 
instrumentation, data handling and flight 
systems to improve existing techniques or 
advance the state of the art. 


The Division launched its first Aries 
sounding rocket during this period. The 
Aries is a single stage rocket capable of 
carrying heavy payloads to high altitudes. 
It is a surplus second stage motor from the 
retired Minuteman I system. The unique 
features of the Aries are its relatively low 
cost and its guidance. The guidance allows 
high altitude flights from restricted ranges 
like White Sands Missile Range with ade¬ 
quate control to keep impact within estab¬ 
lished Range boundaries. This is presently 
the only guided sounding rocket. The pre¬ 
vious guided sounding rocket was the 
German V-2, used by AFGL in the late 
1940’s 

The past two years have seen not only the 
advent of the Aries sounding rocket but also 
much more sophisticated payloads, many 
new state-of-the-art scientific sensors, and 
modern data transmission systems unheard 
of just a few years ago. 

Auroral Measurements: Two launches 
were conducted from Poker Flat Research 
Range, Alaska to measure infrared radia¬ 
tion from the aurora. An IR field widened 
interferometer w T as launched for the first 
time aboard a Sergeant rocket in November 

1977. This payload was successfully re¬ 
covered and refurbished for another flight in 

1978. A 500-pound, multi-instrumented IR 
chemistry payload was successfully carried 
to an apogee of 450 km aboard a Sergeant- 
Hydac rocket in February 1978. This pay- 
load featured a fully instrumented nose cone 
that was ejected from the main payload to 
make separate in situ measurements. 

Spacecraft Charging: Spacecraft charg¬ 
ing effects were studied with the flight of a 
377-pound payload on an Astrobee F vehicle 
at White Sands Missile Range in January 
1978. This payload successfully tested 
engineering models of SCATHA Satellite 
experiments SC4-1 and SC4-2 which varied 
the payload charge by emitting a sequence 
of electrons and positive ions. There were 11 
pyrotechnic-activated mechanisms on the 
recoverable payload; these included four 
doors, two booms, the nose tip, despin unit, 


camera, and vacuum sealed experiment 
packages. A pneumatic actuator was used to 
separate the payload from the burnt out 
sustainer at approximately 8 feet/second. 

Multispectral Measurement Proaram 
(MSMP): The first Air Force Aries vehicle 
was launched in November 1977. This 
guided rocket carried the 3200-pound, dual 
module, TFM-1 payload 227 km above 
White Sands Missile Range, the heaviest 
Aries payload flown to date. A complex 
array of 11 experiments gathered data on 
rocket motor plume characteristics and 
backgrounds. The 1100-pound target engine 
module was successfully recovered after 
completing all scheduled burns and func¬ 
tions. 



MSMP Sensor Module. 

Recoverable Sustainer: The first AFGL 
recovery of a sounding rocket sustainer was 
accomplished in April 1978. A sustainer 
recovery system returned the liquid pro¬ 
pellant Aerobee 170 intact to the desert 


floor after a 190 km science mission above 
White Sands Missile Range. Aerobee 
sounding rockets, employed in over 1,000 
missions to date, are highly valued by the 
scientific community for their clean burn¬ 
ing, non-outgassing, reliable performance. 
As this vehicle is now out of production, 
refurbishment of this sustainer will con¬ 
tinue the AFGL capability of providing 
these rockets for outgassing sensitive ex¬ 
periments. All future AFGL Aerobee 
flights will utilize this recovery system. 

Engineering Research: Advances in 
instrumentation used in today’s experi¬ 
ments require continuing improvements in 
the subsystems this division utilizes to 
support our science divisions. It is of no 
advantage for a scientist to develop a highly 
accurate instrument if equal accuracy is not 
maintained in the telemetry, trajectory, 
attitude control and other critical sub¬ 
systems for which this division is respon¬ 
sible. The efforts conducted in this period 
include both in-house work units and spe¬ 
cific program sponsorship to improve the 
state of the art. 

Telemetry Instrumentation: Teleme¬ 
tered data from a research probe is one of 
many essential elements of a successful 
rocket, satellite or balloon experiment. 
State-of-the-art advances in instrumenta¬ 
tion used in today’s experiments require 
continuing improvements in accuracy and 
resolution of transmitted data. The Balloon 
Altitude Mosaic Measurements (BAMM) 
program is an example of highly complex 
instrumentation. This program requires a 
high bit rate pulse code modulation system 
capable of 14 bit resolution and a buffered 
data storage for correct data transmission. 
A unique PCM telemetry encoder was 
designed with two 1.34 megabit synchro¬ 
nous clocked data links; two identical 1024- 
w'ord X 14-bit random access memory 
storage buffers; a 64-frame sub-frame pro¬ 
viding both analog and digital data, and a 
commandable automatic or manual gain sel¬ 
ector of 1, 4, 16 and 64 respectively. A 
patent application has been submitted for 





46 


the technique of automatic gain selection. 

An improved telemetry system has been 
developed for use with Super Areas type 
rocket payloads. The current 1680 MHz 
receiving systems do not provide reliable 
tracking and data reception during the en¬ 
tire rocket flight. This new 2200-2300 MHz 
telemetry system is both lightweight and 
inexpensive. It includes a flush-mounted 
stripline antenna, a standard telemetry 
transmitter, microminiature subcarrier 
oscillators and a lightweight lithium battery 
pack. With this design, scientists are able to 
obtain reliable telemetry support at estab¬ 
lished launch sites. 



Areas Telemetry System 

The recent emphasis on larger diameter 
rocket payloads such as those used with 
Aries rocket motors has resulted in the 
development of several new types of UHF 
telemetry antenna systems. The typical 
large diameter rocket payload will contain 
multiple telemetry links with RF power up 


to 20 watts for each link. The first acqui¬ 
sition for this project was a reliable RF 
multicoupler based on our critical specifica¬ 
tions. The first antenna system used with 
the MSMP payload consisted of a number of 
surface-mounted, stripline antenna sec¬ 
tions, mounted around the vehicle nose 
section and covered with a heat shield. 

Further in-house study has resulted in 
three specific antenna systems for future 
applications. The Survey Probe Infrared 
Celestial Experiment (SPICE) payload has 
been provided with a flush-mounted, sealed, 
stripline antenna system. A lower cost sur¬ 
face-mounted design has been completed 
and tested, for vehicles with minimal aero¬ 
dynamic heating. The third concept, used 
successfully with the MSMP launches, is a 
single stripline section of antenna that pro¬ 
vides a low cost, directional system for use 
with stabilized vehicle payloads. A micro- 
processor-based adaptive telemetry system 
is being developed. This system will evalu¬ 
ate the signal level received from the scien¬ 
tific instrument while it is in flight and select 
appropriate range amplification levels to 
give the instrument maximum sensitivity. 

Trajectory and Tracking: Tracking of 
research probes and obtaining vehicle tra¬ 
jectory at remote sites from RF tracked and 
ranging systems have been improved 
during this reporting period. 

A 10-inch sphere was instrumented to 
support a density measurement program. 
This design featured an in-house-developed 
UHF PCM telemetry system and a unique 
flush-mounted antenna system. A miniatur¬ 
ized C-Band transponder system was in¬ 
cluded in this payload to facilitate tracking 
by the radars in use at most rocket launch 
sites. This payload was launched at 
Kwajalein Missile Range in support of the 
SAMSO T-Rep Program. The first success¬ 
ful radar trajectory data from this type 
sphere was obtained from this launch. This 
improved trajectory data accuracy will en¬ 
hance the scientific measurements for this 
type of experiment. 

A small, lightweight UHF telemetry RF 



47 


tracker has been developed that weighs less 
than 800 pounds in packing cases. No pack¬ 
age weighs more than 150 pounds and all 
packages meet the maximum allowable 
girth requirements for baggage on commer¬ 
cial airlines. The miniature tracking system 
has been successfully tested at White Sands 
Missile Range (WSMR) and at Poker Fwat, 
Alaska. The tracking system performed 
equally well in desert and arctic environ¬ 
ments. An improved version incorporating 



SPICE Antenna Under Test. 


digital ranging is presently under construc¬ 
tion. 

Real-time trajectory data is limited at 
remote launch sites where radar systems 
are not available. A microprocessor has 
been added to our current tracking systems 
to give them ranging capabilities to provide 
real-time trajectory. A prototype was fabri¬ 
cated and was tested at Holloman AFB, 
New Mexico, in October 1977. The trajec¬ 
tory of the BAMM balloon flight obtained by 


this microprocessor system compared very 
favorably with the WSMR radar trajectory. 
A version with both hardware and software 
improvements is currently being devel¬ 
oped. 

Optical Systems: The BAMM program 
requires the identification of the terrain 
w-hile data measurements are being made. 
The onboard television camera that was 
selected is a space hardened version of a 
standard unit. Pre-emphasis of video sig¬ 
nals for UHF telemetry transmission to 
reduce RF bandwidth without losing reso¬ 
lution was developed. Television pictures 
returned from approximately 100,000 feet 
have outstanding quality. ITe television 
camera utilizes a 10 to 1 zoom lens that cor¬ 
responds to 80 to 800 mm focal length. 
Objects less than ICO feet are easily identi¬ 
fied with this system at 1000,000 feet. T’ * 
commandable function of the camera, zoom 
in or out, lens open or closed, and focus, far 
or near, are important features in obtaining 
high quality television pictures. 

Celestial Aspect Sensor: An aspect 
system that telemeters the position and 
brightness of stars within its two optical 
fields was flown on September 28, 1977 from 
Poker Flat, Alaska. This unit was a proto¬ 
type developed to provide high accuracy 
(one tenth of a degree) attitude data with 
narrow bandwidth telemetry requirements. 
The unit w r as to work with both day and 
night backgrounds. In spite of difficulties 
with solar scattering from a light leak, the 
unit detected the positions of both Mars and 
Jupiter, providing mission-saving attitude 
data for the scientific measurements. 

Vehicle Systems: The addition of the 
Aries rocket to the available inventory pro¬ 
vided the means to fly a new generation of 
large, sophisticated payloads. It also resul¬ 
ted in problems associated with any new 
development. Two significant areas of con¬ 
cern that had to be addressed were the 
boost phase environment a payload would 
be subjected to on this huge rocket and the 
terminal environment these large payloads 
would have to survive to justify their initial 




4# 


expense by being refurbished and reflown. 

The Aries flight environment was studied 
by means of vibration instrumentation 
flown on the MSMP/TEM-1 payload. The 
data gathered was analyzed on our com¬ 
puter based vibration test facility. The 
resultant data has increased our ability to 
project the environment that this class of 
payload will be likely to see, and test pay- 
loads to ensure that they will survive. A 
reentry design handbook was developed to 
assist the design engineer in predicting the 
worst case aero/thermo environment early 
enough in the design phase to avoid being 
locked into marginal configurations. 


RESEARCH SATELLITES 


The Division is responsible for technical 
management of AFGL research satellite 
programs and acts as a central point for 
spacecraft expertise. An additional role of 
the Division is to act as an interface between 
aerospace contractors and personnel from 
satellite control and launch facilities during 
the integration and testing of a spacecraft. 
This role extends to the training of scien¬ 
tists, engineers and control center person¬ 
nel in developing alternate control pro¬ 
cedures to achieve mission objectives if and 
when an anomaly occurs. During this re¬ 
porting period, three research satellite 
programs were provided management and 
engineering guidance from Division per¬ 
sonnel. The first of the efforts, S-77-2, has 
been launched and its mission completed. 
All of the AFGL experiments worked satis¬ 
factorily. The remaining two programs, S- 
78-1 and S-78-2, are in the final phases of 
prelaunch preparations. Both spacecraft 
are scheduled for launch in early 1979. The 
S-78-1 satellite will have an AFGL electron 
energy experiment that will make meas¬ 
urements in the auroral oval. The remaining 
spacecraft S-78-2, SCATHA, has experi¬ 
ments which will vary spacecraft charging 
by emission of electrons and positive ions. 


FREE BALLOONS 

The Division conducts free balloon re¬ 
search and development programs which 
improve the Division’s balloon capabilities 
and benefit the Air Force. The capability 
analyses discussed in the last AFGL Report 
on Research had already caused a search for 
more efficient balloon designs to be started. 
The historical progress in developing thin¬ 
ner balloon grade polyethylene and the 
resulting improvements in altitude per¬ 
formance were included in the analysis to 
determine the probable growth of free bal¬ 
loon capabilities. These new analyses con¬ 
firmed the need for new designs. The re¬ 
search program focused on two inter¬ 
dependent aspects of the problem: a better 
understanding of the properties of the bal¬ 
loon materials and analyzing the stresses on 
a stationary, fully inflated balloon, consider¬ 
ing both temperature and strain effects. 



The Development Trend for Thin Balloon 
Grade Polyethylene Film and its Attendant 
Impact on Altitude. 


film thickness (m.is) 



-19 


The materials study produced accurate 
one-axis stress-strain characteristics of 
present balloon films for use in design and 
analysis computer codes. The work also 
proved that the response of balloon film to 
stress depends on the stress-temp.rature 
history of the film, while the assumption of a 
simple model for time-temperature substi¬ 
tution (equivalence) has been shown to be 
incorrect. These determinations have been 
accompanied by improvements both in test 
methods and in computational analyses for 
determining biaxial stresses. Recent heavy¬ 
load balloon performance combined with the 
foregoing conclusion suggests that the next 
step in materials research is biaxial time- 
temperature stress characterization of bal¬ 
loon films. This will permit more efficient 
and reliable use of existing materials. 

In the study to develop new design 
criteria which will result in more efficient 
balloons, computer codes which model the 
reponse of linearly elastic materials to 
stress principally along the length of the 
material (over the range of temperatures 
the balloon will encounter) have been writ¬ 
ten and tested. They show that previously 
computed stresses were inaccurate and that 
more efficient designs are possible. 

While consulting on the analysis of the 
failure of a NASA balloon, AFGL’s sugges¬ 
tion that failure propagation might result in 
detectable directional evidence was ac¬ 
cepted and evaluated, and now is the basis 
for a significant study by NASA. 

Finally, a design study for a system to 
start the controlled descent of a balloon 
almost instantaneously was begun. Such a 
system will allow recovery of high altitude 
payloads with lower shock and will improve 
the system response time for descent 
sampling programs. 

Tethered Balloons: In 1975, the Tactical 
LORAN System Program Office of the 
Electronic Systems Division asked AFGL’s 
Aerospace Instrumentation Division to 
investigate the feasibility of using a teth¬ 
ered balloon to support a Long flange 
Navigation (LORAN) antenna. They 


wanted a backup antenna system for a 400- 
foot tower if the tower should be destroyed 
by sabotage, hostile action, or violent 
weather. 

The Aerospace Instrumentation Division 
has been working on the design and test of 
this balloon-borne antenna for the last two 
years. 



Balloon Tether Line with Top Loader. 

The tethered balloon antenna system 
designed uses a 45,000 cubic foot aero- 
dynamically shaped balloon. 

The balloon-borne antenna has an alum¬ 
inum center element and three top loaders. 
The center element is made of stranded wire 
coated with two heavy layers of corona dope 
and covered with shrink tubing. The coat¬ 
ings and covering were added to prevent 
corona discharge. The three top loaders 
were fabricated by overbraiding two layers 
of aluminum wire on the three balloon 
tethers. This overbraiding was applied over 
700 feet of the tethers’ 788-foot length. The 
tritethers and the 500-foot balloon tether 
are made of Kevlar. 

Normally on tethered balloon flights a 
UHF instrumentation package is flown to 
control operation of valves and experiments 
and to telemeter data. It w'as realized that 
such a control package could not be flown on 
this balloon antenna configuration because 
the sensitive receiver would almost cer¬ 
tainly be made inoperative by the strong 




radiation and inductive fields from the 
antenna. Unexpected balloon valve opera¬ 
tion and tether cable release might also 
happen because diodes in the circuitry could 
rectify the strong signals that are picked up 
and cause relay closures. 

The Division designed a “Smart" gas 
valve to control balloon operation. This is a 
modified conventional valve equipped with 
its own battery power source. An integral 
aneroid operated switch locks the valve 
open if the balloon breaks away and exceeds 
a preset altitude. A differential pressure 
switch senses internal balloon gas pressure 
and momentarily opens the valve until the 
overpressure is relieved. Building the in¬ 
strumentation into the valve eliminated the 
cumbersome safety package altogether, and 
thereby simplified the rigging by removing 
both the long electrical cables and the pres¬ 
sure sensor inlet tube that tie the safety 
package to the valves and balloon. Remov¬ 
ing the long wires also eliminates the possi¬ 
bility of induced voltage in the wires from 
the strong electromagnetic fields from the 
antenna. 



Balloon “Smart" Valve 


In March 1977, the prototype tethered 
antenna system was deployed at Holloman 
AFB, New Mexico, for measurement of the 
antenna electrical properties and test of the 
mechanical integrity of the antenna system 
parts. Electrical parameters measured in¬ 


cluded input impedance, radiation resis¬ 
tance, and effective antenna height. 

On June 20 and 21, 1978, the balloon 
antenna system was fully deployed at the 
Master TRN-39, LORAN C/D ground 
transmitter site, located at Fort McClellan, 
Anniston, Alabama. 



Antenna Shock-Wave Tests at l.os Alamos 
Scientific nabs. 


The balloon antenna was powered from 
the tower transmitter, and current and 
signal strength measurement made. These 
measurements have been analyzed and 
preliminary results indicate a power output 
of 10 kilowatts as monitored by the evalua¬ 
tion station at Eglin AFB, Florida, 
approximately 250 miles away. Sixteen 
hours of measurements and testing were 
completed on the first day. On the following 
day, the system was recovered in four 




hours. During the time from launch to 
recovery, the weather was good with winds 
never exceeding 10 knots. 

Another tethered balloon program 
requiring considerable development effort 
was conducted for the Los Alamos Scientific 
Laboratories during the fall of 1977. An¬ 
tenna shock-wave testing was to be con¬ 
ducted so that non-conducting tether cables 
and very fine antenna stability were re¬ 
quired. A special tri-tether antenna apex 
tetrahedron deployment device had to be 
designed, fabricated and tested. A recently 
developed laboratory system of high 
strength Kevlar cables was used to produce 
the required non-conductive and stable 
balloon tether. A special balloon deploy¬ 
ment system was also utilized in this very 
mountainous terrain since conventional 
winch vehicles could not be brought into the 
area. Two weeks of successful testing were 
concluded in November 1977 using a 28,000 
cubic foot natural shaped balloon. 

Work was begun on the development and 
fabrication of a special atmospheric sensor 
to be Hown on a tethered balloon. The teth¬ 
ered balloon system and sensor will be used 
to support an Air Force Communications 
Service (AFCS) requirement to measure 
refractive index in the Tyndall AFB, 
Florida, area. The objective is to determine 
if microwave signal fade can be correlated 
with changes in atmospheric parameters, 
especially refractive index. Conventional 
radiosondes could not be used since they are 
commutated by the changing pressure of a 
rising balloon on which they are commonly 
flown. A special time-commutated sonde 
was modified by adding a ventilation blower 
and duct system. A 35 CFM blower was 
fastened inside the exit end of the ducting to 
provide sensor ventilation since the teth¬ 
ered balloon would not have the usual as¬ 
cending balloon air flow. Rechargeable 
batteries were used in place of the conven¬ 
tional water-activated type to power the 
sonde instrumentation and ventilating 
blower. The system will be capable of sens¬ 
ing continuously for 25 hours before battery 



Time Commutated Radiosonde with Forced 
Ventilation. 


recharge is required. Testing in Florida is to 
begin in October and continue for three 
months. 

LOW VISIBILITY MEASUREMENTS 

The Division supported the U. S. Army 
Atmospheric Sciences Laboratory', White 
Sands Missile Range, in the conduct of its 
experiments to measure fog particle size in 
Meppen, West Germany. One series of 
experiments required a tethered balloon 
system to carry a 50-pound payload to 1500 
feet above ground. The system was de¬ 
signed and a 6,000 cubic foot balloon, lights, 
tether cable and w'inch were furnished. 
Since it was not possible for AFGL to send a 
balloon crew to West Germany in February, 
1978, an Army crew was trained to use a 
simplified tethered balloon system. Four 
training flights were conducted at WSMR in 
December 1977. 

AIR LAUNCHED BALLOON SYSTEM 

An extensive series of flight tests was 
carried out on the Air-Launched Balloon 
System (ALBS) development program. 
Upon completion of the tests, the designs of 
major system components were firmed in a 
redefinition phase. This progress has led to 
the present construction of a new “hard- 



52 


ened” version of the ALBS prototype unit. 
Present plans call for the new unit to be 
launched in November 1979 from a C-130 
aircraft flying at 25,000 feet over the White 
Sands Missile Range. After launch the com¬ 
plete mid-air inflation procedure will be 
carried out, followed by ascent of the bal¬ 
loon and payload to float altitude. 

The ALBS flight tests were conducted 
principally at the National Parachute Test 
Range, El Centro, California, under the 
auspices of the Air Force Flight Test 
Center Fourteen tests were conducted 
there, between February and October 1977, 
in which a test vehicle, simulating the 
ALBS unit, was dropped from a C-130. Ini¬ 
tial drop altitude was 10,000 feet; later, it 
became 25,000 feet. (Air speed was 132 kt.) 
A dummy balloon was employed during the 
first half of the test series. Successful 
deployments of the dummy led to use of a 
real balloon in the latter half, including 
limited inflation testing. The tests showed 
that, although the designated parachute 
system could safely extract the ALBS 
module from the aircraft and deploy the bal¬ 
loon for mid-air inflation, improvements in 
system reliability were needed. 

A full-scale live test of the system was 
attempted in January 1978. In this test a 
carrier balloon was to drop the ALBS 


Air Launched Balloon System. 


module from 25,000 feet over the White 
Sands Missile Range, followed by full infla¬ 
tion and ascent of the ALBS balloon. Unfor¬ 
tunately, this test was aborted because of 
problems with the carrier balloon. Exten¬ 
sive resultant damage to the ALBS cryo¬ 
genic inflation unit prevented a repeat test. 

IN-FLIGHT BALLOON CRYOGENIC 
GAS REPLENISHMENT SYSTEM 

The feasibility of employing a cryogenic 
storage system to replenish inflation gas 
lost daily on long-duration scientific balloon 
flights was studied in-house. Such a system, 
in which liquid helium is vaporized and 
directed into the balloon after sunset each 
day, could dramatically improve the cost- 
effectiveness of present long-duration 
flights. Currently, long flight times are 
achieved by using large amounts of dis¬ 
posable ballast. This ballast not only consti¬ 
tutes a disproportionate share of the system 
gross weight; it increases the weight so 
much that a very large and expensive bal¬ 
loon must be used. The proposed cryogenic 
gas replenishment system would permit the 
use of smaller, less expensive balloons. 

The in-house studies developed a com¬ 
puter program to calculate the performance 
of a model system within specified limits. In 
addition, input and output parameters were 
identified for use by the Thermophysical 
Properties Division of the National Bureau 
of Standards in developing and operating a 
mathematical model of a theoretical, self- 
pressurized gas replenishment dewar. 

BALLOON INSTRUMENTATION 

In response to the increased demand for 
higher data rates and real-time data reduc¬ 
tion, scientific balloon instrumentation 
capabilities have been tremendously ex¬ 
panded. UHF command and S-Band tele¬ 
metry systems are providing the flexibility 
and data collection capability demanded by 
the scientific community. 

A highly flexible PCM instrumentation 
system, capable of providing complete con- 






trol of all balloon and experiment operations 
while maintaining a high data rate, has been 
designed and built. This equipment is now 
operational together with a new mobile, 
minicomputer-equipped PCM ground sta¬ 
tion. This system provides the user com¬ 
plete quick look and hard copy data display 
capability, utilizing a computer for real-time 
data reduction and experiment control, 
available for world-wide deployment. 

A significant addition to the PCM capa¬ 
bilities has been the acquisition of a micro- 
processor-based decommuntation system. 
This processor is portable. It facilitates 
ground system checkouts in the user’s 
laboratory and, together with a receiver 
and recorder, can serve as a complete port¬ 
able ground station. 

These improved data acquisition systems 
have successfully supported a wide variety 
of balloon missions from remote operating 
locations in South Dakota, New Mexico, 
Texas, and Alaska. 

A new HF instrumentation system has 
been developed for use where high data 
rates are not required or as a backup to 
line-of-sight limited PCM telemetry. This 
improved HF 1 capability is important to the 
user because of its relatively low cost, the 
simplicity of the ground equipment re¬ 
quired, and its ability to operate far beyond 
the horizon. The new HF system is capable 
of controlling 18 balloon and experiment 
operations, transmitting 28 channels of 
data, and providing the user a timed, hard 
copy visual record of experiment data. This 
system utilizes a new laboratory-designed 
and built data encoder with a measurement 
resolution capability of less than 10 milli¬ 
volts. 

A new VHF, FM transmitter has been 
designed and built in-house. This modular 
unit provides vastly improved reliability 
characteristics in a rugged, low cost design. 
It was developed specifically for use with 
the new encoder to provide the user a higher 
data rate than standard HF equipment at a 
cost significantly below that of PCM equip¬ 
ment. It has been flown successfully a 


number of times. 

Flight tests of the in-house designed and 
developed BLS-3 (Balloon Locating Sys¬ 
tem) have demonstrated a fix accuracy 
comparable to radar. The BLS-3 is an ad¬ 
vanced balloon-borne locating system util¬ 
izing the FAA VHF Omnidirectional Range 
(VOR) transmitter network. This system 
has several technical and cost advantages 
over other locator systems such as radar 
and transponders. The BLS-3 concept does 
not require the balloon to maintain line of 
sight to the balloon control center and can be 
used independently of other orientation 
devices or FAA air traffic controllers. 



BAMM Balloon Payload Being Returned to 
Launch Site Following CH-3 Helicopter Mid- 
Air Retrieval (MAR) Recovery. 


PROJECT BAMM 

The Balloon Altitude Mosaic Measure¬ 
ment (BAMM) program, to obtain infrared 
background measurements for use in the 
design of advanced sensors, conducted 
three development test exercises during the 
reporting period. Two were conducted at 
the AFGL Detachment #1, Holloman Air 
Force Base site, and one was performed at 
the Chico, California, MAP Operating 
Location. The activities culminated in four 
balloon flights, each resulting in various 
levels of successful testing of the BAMM 
payload design. All major sub-systems and 
functions of the BAMM operational flight 



54 


system were successfully tested in flight. 
These included making actual measure¬ 
ments using the specialized infrared and 
video components, and in-flight recovery of 
the development-test payload by CH-3 




Transmitted Pictures from BAMM. 


helicopters utilizing the Air Force Mid-Air 
Retrieval System technique. Operational 
flights and data gathering are planned for 
the second and fourth quarters of 1979. 

PROJECT STRATCOM 

The Division furnished balloon flight and 
technical support to a joint atmospheric 
measurement program involving the U. S. 
Army Atmospheric Sciences Laboratory, 
ERDA and NASA. Data derived from these 
balloon flights have provided information 
for a correlated study of stratospheric 
composition, dynamics and thermodynam¬ 
ics between 20 and 38 km altitude. 

Two missions were flown during Septem- 
bej 1977. The first flight on September 28 
carried a payload of 1,500 pounds consisting 
of seven experiments, to a peak altitude of 
92,000 feet. After a six-hour flight, the pay- 
load was recovered a few hundred miles 
northeast of the launch site, Holloman Air 
Force Base. A second flight of 32 hours 
began on September 29 and carried 24 ex¬ 
periments to an altitude of 126,000 feet. 

Results obtained will provide further un¬ 
derstanding of the transport and extent of 
atmospheric pollutants and their threat to 
human activities. Of particular importance 
will be measurements of Freon which re¬ 
cently has caused concern because of its 
possible effects on the atmospheric ozone 
balance. 

ATMOSPHERIC SAMPLING 
PROGRAMS 

For a number of years, the Aerospace 
Instrumentation Division had been provid¬ 
ing balloon operations support to atmos¬ 
pheric sampling programs of the Depart¬ 
ment of Energy, NASA and the Army. 
With the reduction of personnel at AFGL 
Detachment 1 and deactivation of AFGL 
Detachment 3, Chico, California, in June 
1976, Headquarters AFSC directed this 
support be contracted out with AFGL act¬ 
ing as technical monitor. In October 1976, 
the Physical Sciences Laboratory of New 




55 


Mexico State University was awarded this 
contract and, after a period of training, be¬ 
gan providing operational support to the 
sampling programs. Fifty balloon flights 
were conducted from Holloman Air Force 
Base, Panama and Alaska. The latter two 
locations required aerial recovery of the 
payloads by C-130 aircraft 
Project “Ash Can,” one of the sampling 
programs, provides measurements of radio¬ 
activity, fluorocarbons, chlorine and other 
atmospheric constituents which have or 
could have an impact on health. A notable 
achievement occurred when measurements 
were obtained on atmospheric radioactivity 
caused by the reentry of the Russian 
COSMOS satellite. Combining Ash Can 
flight series at Alaska and Panama with 
AFGL’s sampling program has reduced 
travel, per diem, and transportation costs to 
AFGL. AFGL benefits from work con¬ 
ducted under the Ash Can program in the 
areas of rigging, command and control, and 
systems integration. 



BAMM Flight System Ready for Launch. 


PIONEER-VENUS DROP TESTS 


On May 20, 1977, the main probe for 
NASA’s Pioneer-Venus mission was 
successfully tested by releasing the probe 
from a balloon, 27 km above White Sands 
Missile Range. All test objectives were met 
and the probe was qualified for Venus entry. 
The test consisted of deployment of the 
probe parachute, separation of its atmos¬ 
phere entry heat shield; and, after nine 
minutes of parachute descent, separation of 
the parachute for simulated flight down to 
Venus’s surface. 


AIR FORCE GEOPHYSICS 
LABORATORY 

SCIENTIFIC BALLOON SYMPOSIUM 


The Ninth and Tenth Air Force Geo¬ 
physics Laboratory Scientific Balloon 
Symposia were held at Wentworth-By-The- 
Sea, Portsmouth, New Hampshire, during 
October 29-22,1976 and August 21-23,1978. 
These meetings were attended by large 
numbers of engineers and scientists affili¬ 
ated with government, industry, and uni¬ 
versities from the United States and several 
foreign countries. Sessions were concerned 
ivith scientific balloon operations, balloon 
technology, manned flights, balloon-borne 
experiments and instrumentation, and air¬ 
ships. The Keynote Address of the Tenth 
meeting was given by Dr. Hans Mark, 
Under Secretary of the Air Force. Proceed¬ 
ings of the ninth meeting have been pub¬ 
lished and the proceedings of the tenth 
meeting are in the process of being pub¬ 
lished. A total of 63 papers were presented 
at these meetings. 



56 


JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 


BALLARD, H. (Atm. Sci. Lab., White Sands Missile 
Range, N. M ), HERRINGTON, P., HUDSON, F. 
(Sandia Labs., Albuquerque, N. M.), and KORN, A. 
The STRATCOM VI Program 
U. S. Army R&DTech. Rpt„ ECOM-6734(May 1977) 

BALLARD, H. (Atm. Sci. Lab., White Sands Missile 
Range, N. M.), HUDSON, F. (Sandia Labs., 
Albuquerque, N. M.), and KORN, A. 

Stratospheric Composition Balloon-Borne 
Experiment, J.l-Jti September 1976 
U. S. Army R&DTech. Rpt., ECOM-5830(October 
1977) 

Wilton, R. E. 

AFGL Solar Eclipse Program Operational 
Requirement a 

AFGL Tech. Memo. No. Ill (August 1978) 


Dwyer, J. F. 

A New Zero P re moire Free Balloon Shape 
10th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(21-23 August 1978) 

Zero P re moire Balloon Shapes, Past, Present and 
Future 

Symp. on the Sci. Use of Balloons and Related Tech. 
Problems, Innsbruck, Aus. (8-9June 1978) 

Gildenberg, B. D. 

Meteorological Interface with Balloon Operations 
9th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(20-22 October 1976) 

Korn, A. 0. 

Balloon-Borne LOR AX Emergency Antenna 
10th AFGL Sci. Balloon Symp., The Wentworth-by- 
theSea, Portsmouth, N. H. (21-23 August 1978) 


TECHNICAL REPORTS 
JULY 1976 - DECEMBER 1978 


PAPERS PRESENTED AT MEETINGS 
JULY 1978 • DECEMBER 1978 


BALLARD, H. N. (Atm. Sci. Lab., White Sands 
Missile Range, N. M ), HERRINGTON, P. B., 
HUDSON, F. P. (Sandia Labs., Albuquerque, N. 
M.)and KORN, A. O. 

The STRATCOM VI Program of Correlated 
Measurements of Stratospheric Composition and 
Other Parameters Between 2.5 and J9 Kilometers 
Altitude: Sept. 25-25. 1975 
9th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(20-22 October 1976) 

Ballard, H. N. (Atm. Sci. Lab., White Sands 
Missile Range. N. M ), IZQUIERDO, M. (Univ. of 
Texas, El Paso, Texas), KORN, A., and PAGE, W. 
(NASA Ames Res. Ctr., Moffett Fid., Calif.) 
Stratospheric Composition Balloon, Aircraft and 
Rocket-Borne Experiments (Systems, Instruments, 
Trajectories, Supporting Measurements I 
10th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(21-23 August 1978) 

Burnett, B. B., Maj. 

Current Air Force Balloon Test Capabilities 
9th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(20-22 October 1976) 

CARTEN, A. S.,Jr. 

The Air-Launched Balloon System Development 
Program 

9th AFGL Sci. Balloon Symp., Portsmouth, N. H. 
(20-22 October 1976) 

ALBS Flight Test Program 

10th AFGL Sci. Balloon Symp., Portsmouth, N. H. 

(21-23 August 1978) 


BALLARD, H. N. (Atm. Sci. Lab., White Sands 
Missile Range, N. M.). HERRINGTON, P. B., 
HUDSON, F. P. (Sandia Labs.. Albuquerque, N. 

M ). and Korn, A. O. 

The STRATCOM VI Program of Correlated 

Measurements of Stratospheric Composition and 

Other Parameters Between 25 a ltd .19 Kilometers 

Altitude: September 24 it 25, 1975 

Proc., 9th AFGL Sci. Balloon Symp., 20Oct. to220ct. 

1976, 

A FGL-TR-76-0306 (15 December 1976) 

Burnett, B. B., Maj. 

Current Air Force Balloon Test Capabilities 

Proc., 9th AFGL Sci. Balloon Symp.. 20 Oct. to220ct. 

1976, 

AFGL-TR-76-0306 (15 December 1976) 

Carten, A. S., Jr. 

The Flight Test Aspects of the Air-Launched Balloon 
System t ALBS) Dei'elopment Program 
AFGL-TR-76-0196 (30 August 1976) 

The Air Launched Balloon System Dei'elopment 
Program 

Proc., 9th AFGL Sci. BalloonSymp.,200ct.to220ct. 
1976, 

AFGL-TR-76-0306 (15 December 1976) 

Flight Tests of the Air-Launched Balloon System 
t ALBS) Prototype Model 
AFGL-TR-78-0074 (23 March 1978) 

Cordella, R. H., Jr., Capt. 

An Examination of the Temperature Measuring 
Accuracy of a Flowmeter System used with Balloon- 
Borne Atmospheric Samplers 
AFGL-TR-77-0034 (2 February 1977) 

An Autora nging Balloon Altimeter: A Single Pressure 
Transducer Monitors Altitude Irom 0 to 44 Kilometers 
with ,10 Meters Resolution 
AFGL-TR-78-0023 (26 January 1978) 




57 


About the Development at a Second Generation 
Atmospheric Sampler C out rot and Data System 
SCADS-,' 

AFGL-TR-78-0065 (16 March 1978) 

Gildenberg, B. D. 

Meteorological Interface with Balloon Operations 
Proc., 9th AFG1 Sci. Balloon Symp., 20 Oct. to 22 Oct. 
1976, 

AFGL-TR-76-0306 (15 December 1976) 

L APING, H., and GRIFFIN, A. R. 

BLS-.I Balloon Locating System 
AFGL-TR-77-0087 (12 April 1977) 

McKenna, E. F. 

Sounding Rocket Delta Velocity System 
AFGL TR-76-0241 (8October 1976) 

Nolan, G. F., Ed. 

Proceedings, 9th AFGI Scientific Balloon Symposia m. 
JO Oct. tojJ Oct. 1976 
AFGL-TR-76-0306 (15 December 1976) 

Sowa, M. J. 

A Computer Controlled Tracking System: Interface 
Circuits Design 

AFGL-TR-77-0045 (15 February 1977) 

Stark, C. N., and Williams, A. K., Capt. 

Sounding Rocket Flight Data Summary 1966-1976 
AFGL-TR-78-0120 U5 May 1978) 

Wright, J. B. 

Computer Programs for Tethered-Balloou System 
Design and Performance Evaluation 
AFGL-TR-76-0195(26 August 1976) 

Computer Programs for Three-Dimensional Cable 
Problems in Tethered-Balloou Applications 
AFGL-TR-77-0203115 September 1977) 


CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 • DECEMBER 1978 


Buck, R. F., Fike, R. M., and Gwinn, C. 

M. (Okla. State Univ.) 

Rocket Instrumentation Support Services 
AFGL-TR-78-0207 (31 August 1978) 

Bumgarner, R. A., and Gilcrease, A. A. 

(N. M. State Univ.) 

Sounding Rocket and Balloon System Support 
AFGL-TR-76-0228 (13 September 1976) 

harron, R., Campbell, T., Dimilla, 

., and SMART, L. (Wentworth Inal. ofTechnol., 
Boston, Mass.) 

Electronic Supporting Units for Sounding Rocket 
Payloads 

AFGL-TR-78-0163 (31 March 1978) 


Davin, M. J. (Wentworth Inst., Boston, Mass.) 
Payload Instrumentation for Probing Rockets 
AFGL-TR-76-0163 (30 April 1976) 

Fike, R. M. (Okla. State Univ.) 

Trajectory Determination and Telemetry Receiring 
System Evaluation 
AFGL-TR-76-0276 (1 November 1976) 

Johnson, R. W., Mattice, J.A. 

Aerojet Liquid Rocket Co., Sacramento, Calif.) 

Engineering Review of the Assembly and Preparation 
of Sou nding Rockets 
AFGL-TR-77-0162 (July 1977) 

MARKS, R. H. (Northeastern Univ., Boston, 
Mass.) 

Evaluation Studies of Telemetry System Components 
AFGL-TR-77-0074 (i 1 January 1977) 

Evaluation Studies of Telemetry System Components 
AFGL-TR-78-0142 (11 May 1978) 

McAnally J. V., Engel, C. D„ and 

LaPOINTE, J. K. (Remtech, Inc., Huntsville, Ala.) 
Reentry Design Handbook for Sounding Rocket 
Payload 

AFGL-TR -78-0019 (December 1977) 

Morin, R. (Northeastern Univ., Boston, Mass.) 
Motordrive Systems for Sounding Rocket Payloads 
AFGL-TR-78-0252 (October 1978) 

Otis, J. M. (Wentworth Inst., Boston, Mass.) 
Model Sensor for Project Zip 
AFGL-TR-77-0088(31 March 1977) 

RAND, J. L. (Texas A&M Univ.) 

Define and Study Free Balloon Design Problems 
AFGL-TR-78-0295 (November 1978) 

Design and Analysis of Single Cell Balloons 
AFGL-TR-78-0258 (August 1978) 

SUKYS, R. (Northeastern Univ., Boston, Mass.) 
MSMP T i trier Testi ng a nd Progra m in ing I nstru merits 
AFGL-TR-77-0206 (1 May 1977) 

VESPRINI, R. L., and HAGAN, M. P. (The 
Trustees of Emmanuel Coll., Boston, Mats.) 

Report on Atmospheric Environment Interactions 
with Free and Tethered Balloons 
AFGL-TR-77-0100 (April 1977) 

Waterman, A., and Henry, D. G. <n m 

State Univ.) 

Resea rch a nd Development of A nten nas for Rockets 
and Satellites 

AFGL-TR-78-0095 (March 1978) 

Stripline Antennas fora Small Sphere 
A FGL-TR-77-0064 (February 1977) 



58 



The SCATHA Satellite, showing the arrange¬ 
ment of booms, the orbital plane close to the 
ecliptic, and the spin axis maintained perpen¬ 
dicular to the earth-sun line. 





IV SPACE PHYSICS DIVISION 


The technical program of the Space 
Physics Division is concerned with space 
environment effects on Air Force systems. 
Particles, such as electrons and protons, 
which permeate near-earth space, can 
degrade satellite electronics and sensors by 
radiation damage, and they can interfere 
with and disrupt on-board computer sys¬ 
tems. Magnetic storms and sub-storms 
create ionospheric disturbances which de¬ 
grade communications to and from satel¬ 
lites, and which can cause surveillance, 
detection, and tracking systems to become 
ineffective or to give false information. 
Space is a dynamic environment with daily 
and seasonal variations and with naturally 
occurring disturbances. These variations 
and disturbances are caused by the sun. 
Therefore, the Division’s program deals 
with the phenomenon of solar activity and 
how to predict it. It is concerned with the 
radio and particle emissions resulting from 
such activity and with the propagation of 
solar particles through the interplanetary 
medium to the vicinity of the earth. It deals 
with the interaction of such particles with 
the earth’s magnetosphere, and with the 
particle fluxes and energies within the mag¬ 
netosphere. It includes investigation of 
magnetic disturbances and storms and iono¬ 
spheric irregularities resulting from par¬ 
ticle precipitation and varying electron den¬ 
sities. 

In accomplishing its programs, the Divi¬ 
sion observes and monitors the important 
parameters in near-earth space with instru¬ 
ments carried by satellites and by a dedi¬ 
cated, heavily instrumented KC-135 which 
functions as an airborne ionospheric obser- 




t;o 


vatory. The flying observatory is used in a 
program of ionospheric mapping and in the 
study of ionospheric disturbances both in 
the arctic and in the equatorial regions. 

To complement the satellite anil aircraft- 
borne observations, the Division maintains 
a number of ground-based observational 
sites such as the radio observing site at 
Sagamore Hill, Massachusetts, the iono¬ 
spheric observatory- at Goose Bay, Labra¬ 
dor, its network of seven magnetic dis¬ 
turbance monitors across the United States 
and its Solar Research Branch at the NSF- 
operated Sacramento Peak Observatory. 

THE SOLAR RESEARCH BRANCH 

The Solar Research Branch is located in 
Sunspot, New Mexico, as a tenant at the 
Sacramento Peak Observatory (SPO), 
which is a national center for solar physics 
operated by the Association of Universities 
for Research and Astronomy, Inc., under 
contract to the National Science Founda¬ 
tion. The task of the Solar Research Branch 
is to identify, predict, and understand the 
physical mechanisms on the sun which give 
rise to solar flares and high speed solar wind 
streams, because these are the phenomena 
which produce environmental disturbances 
that disrupt Air Force systems. In addition, 
the Solar Research Branch is now pursuing 
methods to restore images which have been 
degraded by atmospheric turbulence, and is 
just beginning a study of variations of the 
sun’s ultraviolet output to determine if these 
changes are large enough on a short enough 
time scale to affect the character of the 
ionosphere or influence weather patterns. 

Flare Prediction: A major portion of the 
solar research carried on by the Branch is 
dedicated to the physics of solar flares and to 
the solar conditions leading to flares. The 
efforts are directed along two distinct 
avenues: a statistical approach toward an 
objective flare forecast, and a detailed study 
of the physical processes associated with 
flares. Both approaches utilize solar data 
obtained from the Air Weather Service 
Solar Optical Observing Network (SOON) 


in addition to the telescopes available at 
Sacramento Peak Observatory. The tech¬ 
niques developed through these studies are, 
in turn, applicable to the SOON observing 
sequences and to the operation of the inter¬ 
national forecast center in Boulder, Color¬ 
ado (a part of the National Oceanic and 
Atmospheric Administration (NOAA)). 

The statistical approach to solar flare 
forecasting incorporates a procedure known 
as Multivariate Discriminant Analysis, in 
which about thirty daily-observed solar par- 



la) Solar Hare on September 14. 1977. Note 
twisted dark fibrils on right side at arrow, 
indicating energy buildup. In (b), taken seven 
hours later, the fibrils have relaxed into a more 
radial configuration. 




61 


ameters are compared with the magnitude 
of flare activity the following day. The 
Multivariate Discriminant Analysis com¬ 
puter program has the ability to maximize 
the discrimination between possible activity 
outcomes (no flare, small, medium, or large 
flare) in terms of combinations of the input 
parameters. The program is “trained” on 
historical data and subsequently applied to 
future time in which only the input solar 
parameters are known. 

New solar parameters, especially those 
incorporating the basic processes of flare 
energy storage and release, are being 
studied by the Solar Research Branch. 
Observations of sunspot motions and active- 
region geometry have proven useful in 
tracking the buildup of energy in sheared 
magnetic fields. The configuration of the 
hydrogen-alpha fibril structures indicates 
the state of shear in a flare-producing region 
and may be used to estimate the upper limit 
on the energy released by any subsequent 
flare at that location. 

The real-time capacity for a display of the 
motions of all sunspots in an active region is 
being developed jointly by Solar Research 
Branch and Air Weather Service personnel, 
and will be generated by SOON telescopes 
for use at the forecast center. 

The advantage in pursuing simulta¬ 
neously both the statistical and the physical 
approaches to flare prediction is that Multi¬ 
variate Discriminant Analysis can test the 
relative significance of possible new input 
parameters in terms of the success of pre¬ 
viously used parameters. 

Geomagnetic Disturbances and 
Coronal Holee: To help the Air Weather 
Service predict geomagnetic activity, the 
Solar Research Branch has developed an 
observing program to locate coronal holes 
on the sun. These regions of low density and 
temperature in the corona are Sources of 
recurrent high-speed streams of solar wind. 
The impact of these streams on the geo¬ 
magnetic field disturbs the field. Thus, if 
coronal holes can be detected reliably, re¬ 
current geomagnetic disturbances can be 


predicted up to ten or more days in advance 
of their occurrence. The most reliable way 
to detect them is from full-disk solar pic¬ 
tures taken in x-rays from rockets or satel¬ 
lites. This is not feasible for long-term 
monitoring. Howe ver, optical monitoring of 
the corona is possible on an almost daily 
basis, and a collaborative study done by 
Solar Research Branch and Sacramento 
Peak Observatory personnel showed that 
this type of monitoring could detect the 
sources of recurrent geomagnetic disturb¬ 
ances 70-80 percent of the time (compared 



_A 5303 


A comparison of equatorial 5303 % emissivi- 
ties with averaged A,,, corrected for the 
equinox effect. The day of the largest A,, is 
November 13 1976, and time increases in a 
clockwise direction. A lag of 5 days has been 
introduced between central meridian passage 
on the sun and A,' *1 the earth. The circle 
represents zero for A,,, and A,, varies from 6 to 
35 in this i'gure. Tne dashed curve is the 
average log emissivity, ranging from log 2 x 
10 " at the circle to a minimum of log 2.35 x 
10 H> in this figure. Note the coincidence (at 
lower left) of the only major recurrent dis¬ 
turbance and the deepest coronal hole. A 
minor geomagnetic disturbance is connected 
with another hole at upper right. 






62 


with 60-65 percent based simply on 27-day 
recurrence due to solar rotation). The Solar 
Research Branch now observes the corona 
daily (weather permitting) in the 5303 A 
line of Fe XIV, and compiles data twice- 
weekly into maps of coronal brightness and/ 
or emissivity, with coronal holes identified. 
These maps and accompanying numerical 
predictions of geomagnetic disturbances are 
telecopied to Air Force Global Weather 
Central for use in geomagnetic activity pre¬ 
dictions. 

Speckto Interferometry: The Solar 
Research Branch began a major effort to 
greatly improve imaging through the 
Earth’s atmosphere using the astronomical 
technique known as speckle interferometry. 
The ultimate objectives of this project are to 
improve solar surface images by a factor of 
ten over those now obtainable and to adapt 
existing large stellar telescopes to obtain 
increased resolution on Earth satellites. 
During this period, substantial progress 
was made on both objectives. 

There are two promising approaches for 
solar surface image enhancement. A con¬ 
tractor has perfected a method to process 
solar photographs to produce images with a 
factor of ten increase in resolution. Solar 
Research Branch scientists hope to use this 
technique to study the time evolution of 
small scale solar magnetic fields. A second 
method for improving solar images is to use 
an active-optics device to reconstruct in 
real-time images free from atmospheric dis¬ 
tortion. Using Laboratory Director Funds, 
the Solar Research Branch has arranged to 
use such an instrument in conjunction with 
the Sacramento Peak Observatory Tower 
Telescope. 

The Solar Research Branch has made 
substantial progress on low-brightness and 
satellite image reconstruction techniques. 
Most technical problems are now solved and 
demonstrations on actual satellites are 
planned. Three key problems were solved in 
1977-1978: developing equipment capable of 
obtaining data for faint objects, developing 
methods to calibrate results, and investiga¬ 


ting means to produce reconstructed 
images, rather than just the size and shape 
of objects as was previously possible. In 
conjunction with a contractor, the Solar 
Research Branch constructed a television 
array camera to record individual photon 
arrivals at the telescope. This system allows 
observations of objects 1000 times fainter 
than previously possible, including most 
earth satellites. Branch scientists also per¬ 
fected a computer analysis system to cali¬ 
brate the results to give quantitative size 
and shape information for objects too small 
to image. This system was used to obtain 
the first direct size measurements of several 
asteroids, as well as Saturn’s moons. 
Finally, other computer methods to recon¬ 
struct images fully were investigated. This 
method was tested on several objects, in¬ 
cluding the asteroid Vesta, the surface of 
which has never been directly resolved. 
Although the data are of insuf cient quality 
to show surface structure such as craters, 
one can see that the asteroid is slightly elon¬ 
gated. Work will continue along this line in 
1979. 



Image of the asteroid Vesta obtained by image 
reconstruction using the techniques of speckle 
interferometry and speckle imaging. Note the 
slightly elongated shape. 




63 


Speckle interferometry shows consid¬ 
erable promise for other scientific purposes. 
Following AFGL analysis, NASA has 
adopted this t?chnique as one method in 
searching for planets around nearby stars. 
The very accurate positions of one star rela¬ 
tive to another which speckle interfer¬ 
ometry produces will enable NASA to see 
tiny wobbles in a star’s motion indicating a 
planetary object in orbit around the star. 
Another possible use of speckle interfer¬ 
ometry would be a search for black holes in 
the centers of galaxies. 

Solar Variability: There is mounting 
evidence that the sun has long and inter¬ 
mediate-term variability in its energy out¬ 
put. These changes may translate into 
upper atmospheric and weather pattern 
changes. During parts of the 17th and 18th 
centuries, a decrease in worldwide temper¬ 
ature accompanied a virtual lack of sun¬ 
spots. Astronomers at the Lowell Observa¬ 
tory in Flagstaff, Arizona, have reported 
changes in the outer planet brightness 
inversely proportional to the number of sun¬ 
spots. These changes, up to 2 percent per 
year, are probably triggered by changes in 
the solar ultraviolet energy output. 

To confirm and determine the source of 
planetary brightness changes, the Solar 
Research Branch has begun a program 
under Laboratory Director’s Fund support. 
Due to changes in atmospheric pollutant and 
transmission parameters, it is difficult to 
observe solar energy output changes di¬ 
rectly. The Lowell Observatory Program 
avoids this problem by comparing planetary 
brightness (which presumably represents 
solar brightness changes) to a large set of 
nonvarying stars. However, one cannot rule 
out changes in the physics of the planetary 
atmospheres causing the apparent bright¬ 
ness change. To check whether the sun itself 
is varying, Branch scientists have devised 
observations of objects without atmos¬ 
pheres, and also are extending their obser¬ 
vations to the ultraviolet spectral region 
which would have greater effects on the 
upper terrestrial atmosphere. This effort 


requires routine access to a large stellar 
telescope equipped with a good brightness- 
leeording photometer. A surplus 48-inch 
satellite-tracking telescope facility in 
Cloudcroft, New Mexico, was acquired to 
make the measurements. 

Generalization of Solar Activity: From 
studies of the sun alone it is impossible to 
tell whether solar activity (flares, corona, 
etc.) is a unique property of the sun. During 
this period, Solar Research Branch scien¬ 
tists have studied several classes of stars 
and confirmed the existence of solar-type 
activity. In fact, the sun exhibits rather low 
levels of activity relative to many stars. 

Two classes of stars have been analyzed in 
particular detail. Using equipment at the 
Kitt Peak National Observatory in Tucson, 
Arizona, high resolution spectral profiles for 
stars similar to the sun were obtained. 
Losing these profiles with models developed 
at the University of Colorado has allowed 
estimates of the physical conditions within 
the stellar chromospheres. Also studied 
were the M-dwarf stars, stars smaller, 
cooler, and much more active than the sun, 
showing such large flares that the whole 
star may brighten by a factor of 100. Similar 
activity on the sun increases the solar 
brightness by, at most, 1 percent. Yet, we 
have been able to confirm that this activity 
is very similar to solar flare processes. This 
work will be extended using the NASA 
International Ultraviolet Explorer Satel¬ 
lite. The flare mechanisms will be studied in 
detail and coronae may be detected around 
these stars for the first time. 

Other Projects: Results were published 
from joint Sacramento Peak Observatory/ 
OSO-8 satellite studies showing that solar 
super-granular convective velocity patterns 
extend upward into the chromosphere/ 
transition zone region. This is the first evi¬ 
dence that steady quiet-sun large-scale 
motions below the surface can transfer 
material into the high solar atmosphere. 
This may he very significant to problems of 
energy balance, heating of the corona, and 
interaction of magnetic and velocity fields. 




64 


The Solar Research Branch and collabor¬ 
ators at the University of Colorado will 
continue this work as guest investigators on 
the FY 79-80 NASA Solar Maximum Mis¬ 
sion satellite. 

Oscillation observations were analyzed to 
reveal a non-uniform solar rotation beneath 
the surface. The source of these five-minute 
oscillations has been a mystery since their 
discovery in 1960. Solar Research Branch 
personnel and their collaborators at UCLA 
have now explained this phenomenon as 
non-radial p-mode oscillations of the entire 
solar convection zone which extends some 
200,000 km below the surface. 

The first detailed observations of coronal 
holes were made at radio frequencies. These 
were compared with X-ray and optical 
photographs. Modeling of the electron den¬ 
sity and temperature of coronal holes has 
begun as a contractor effort. 

Analysis of high-resolution magnetic field 
observations indicates that probably all 
solar fields occur in small clumps with 
strengths of 1000-1500 gauss. Any weak 
field which might exist must be less than 50 
gauss, which indicates that even in the quiet 
sun at least 85 percent of the magnetic 
energy in the photosphere resides in strong 
fields. 

Simultaneous optical and radio observa¬ 
tions of a flaring region were obtained. The 
radio measurements indicate dramatic 
polarization changes occurring within the 
hour previous to the flare. A search for the 
optical counterpart to these polarization 
changes has begun. 

DEFENSE METEOROLOGICAL 
SATELLITE PROGRAM 

Topskto Ionosphere Plasma Monitor: 

The Space Physics Division is supplying a 
series of Topside Ionosphere Plasma Moni¬ 
tor instruments for flight on Defense 
Meteorological Satellite Program (DMSP) 
satellites. They will provide near real-time 
measurements of the topside ionospheric 
density, scale height, F-region critical fre¬ 


quency and the nature of small-scale plasma 
irregularities. These parameters are used in 
frequent updating of the Air Weather 
Service model of the topside ionosphere and 
F-region peak. The model is used in the 
frequency management of Air Force 
communications and surveillance systems. 

The data on small-scale plasma irregular¬ 
ities is used in the investigation of the scin¬ 
tillation of signals received at the ground 
from satellites in orbits high enough so that 
their signals pass through the topside iono¬ 
sphere to reach the earth. Spatial irregular¬ 
ities on the scale of a few meters to one 
hundred kilometers in extent cause scatter¬ 
ing, deviation and diffraction of these sig¬ 
nals. When observed at a fixed receiving 
station on the ground, the overall effect is 
called “scintillation" and can cause data loss 
or total loss of signal from communications 
satellites. The phenomenology of these scin¬ 
tillations is not } 3t fully understood and the 
data acquired will be used both to build up a 
statistical description of satellite signal 
scintillations and in studies of the processes 
forming the plasma irregularities them¬ 
selves. 

The instrument, designated SSI/E, con¬ 
sists of separate thermal energy positive ion 
and electron sensors mounted on a boom 
which holds both sensors clear of the dis¬ 
turbed plasma around the satellite. The 


SSI/C SCNSQW LO CA TIONS. BLOCK X). F2 



Block 5D F2 DMSP spacecraft showing :he 
boom mounted ion and electron sensors. 


66 


satellite is three-axis stabilized, so that the 
planar ion sensor faces the direction of 
travel at all times. Attitude is not critical to 
the operation of the electron sensor. 

One set of instruments was launched in 
mid-1977 into a dawn-dusk circular orbit. 
The ion density data at the satellite altitude 
of 830 km shows several important features. 
They include: a) relatively smooth variation 
at midlatitudes, b) highly variable structure 
in both polar caps and auroral zones, c) the 
midlatitude trough, seen most clearly in the 
northern hemisphere, and d) the local max¬ 
imum and minimum in plasma density ob¬ 
served at the equator, at local sunset and 
sunrise, respectively. 

The nearly continuous measurement of 
plasma density is interrupted every 128 
seconds and a voltage ramp is applied to 
each sensor. Analysis of the currents drawn 
to the sensors at these times yields data on 
ion and electron temperature and spacecraft 
potential, which are required to determine 
plasma scale height and hence F-region 
critical frequency. 

DMSP Electron Spectrometer: The 

Space Physics Division has designed, built 
and calibrated four electron spectrometers 
designated SSJ/3 for the Space and Missile 
Systems Organization to be flown on De¬ 
fense Meteorological Satellite Program 
satellites. Two of these sensors have al¬ 
ready been flown and two more are awaiting 
flights. Each spectrometer consists of two 
electrostatic analyzers. The spectrometers 
will measure the spectrum of precipitating 
electrons from 50 eV to 20 keV. The DMSP 
low altitude (400 nm) polar orbiting satellite 
passes through the precipitating electrons 
that are responsible for the aurora. The data 
from the SSJ/3 instrument is used to deter¬ 
mine the boundaries of the auroral oval. 
Data from the SSJ/3 were used to verify the 
feasibility of X-ray imaging in the auroral 
regions. 

Electron spectral measurements will be 
used by the Space Physics Division to relate 
electron precipitation with substorm phe¬ 
nomena. This effort is being carried out in 



T 1 


Ion density measurement at 830 km altitude 
from planar ion sensor on DMSP Block 5D F2 
satellite. The smooth variation of the plasma 
at midlatitudes is in contrast with the rapid 
density fluctuations over both polar and 
auroral regions. 

collaboration with other scientific groups. 
The SSJ/3 data is available to the general 
scientific community through the World 
Data Center at the National Oceanic and 
Atmospheric Administration. 

A more sophisticated version of the SSJ/3 
is on the P78-1 satellite. This instrument 
gives high resolution pitch angle informa¬ 
tion for precipitating particles along mag¬ 
netic field lines. 

THE ENERGETIC PARTICLE 
ENVIRONMENT 

Environmental Effects on Space Sys¬ 
tems: The vulnerability of microelectronics 
to natural radiation limits operational life¬ 
times of Air Force satellite systems. In 
recent years, it has become appreciated that 
Complementary Metal Oxide Semi¬ 
conductor (CMOS) devices and charge 
coupled devices (CCD) used in satellite 
systems to meet weight and power con¬ 
straints are susceptible to environmental 
damage. It has been discovered, for ex¬ 
ample, that some CMOS circuitry is 1 to 2 
orders of magnitude more vulnerable to 
radiation than had been previously sus¬ 
pected. The source of the radiation damage 





66 



The SSJ "1 Electron Spectrometer. 

is currently believed to be high energy 
electrons (1.0 - 10.0 MeV). TTiese high 
energy electrons are difficult to shield 
against and may increase the radiation dose 
by an order of magnitude over that 
previously expected in many orbits that Air 
Force satellite systems will operate, such as 
the 60 degree inclination semisynchronous 
orbit of the Global Positioning System. 

At present, the knowledge of the high 
energy electron environment at satellite 
altitudes is summarized in the model devel¬ 
oped by the National Space Science Data 
Center. This model is based primarily on 
observational data obtained between 1959 
and 1968, and although the model itself 
extends to about 4 MeV, very little observa¬ 
tional data were available for energies 
greater than 1 MeV. Because the mgjor por¬ 
tion of the total radiation environment at 
satellite altitudes is less than 1 MeV, little 
attention has been devoted to detailed 
modeling of the high energy portion of the 
energetic electron spectrum. The existing 


high energy electron model is not accurate 
enough in the energy range 1.0 -10.0 MeV 
to properly assess satellite electronic com¬ 
ponent lifetimes. The few observations that 
are available tend to confirm the suspicion 
that energetic electrons in the 1.0 - 10.0 
MeV range are primarily responsible for 
enhanced dosage rates. These measure¬ 
ments, however, are neither accurate 
enough nor numerous enough to generate a 
realistic model of the high energy electron 
environment. 



Proton flux model based on S72-1 data. 

For these reasons, there exists the need 
to perform in situ measurements of the flux 
of high energy electrons for various levels of 
solar activity and to incorporate these re¬ 
sults into a model that can be used to 
determine radiation effects on satellite- 
borne electronic components. This meas¬ 
urement and modeling program needs to be 
undertaken even if the current Air Force 
Materials Laboratory program to produce 
hardened CMOS is successful since the new 
generation of microelectronics, memory 
elements and high speed circuits will be vul¬ 
nerable to electron dosage integrated over a 
time period commensurate with planned 
satellite lifetime. 

The Air Force Geophysics Laboratory 
has begun a technical program to develop a 
realistic model of the high energy electron 
environment at satellite altitudes. The Pro- 



67 


gram includes four principal efforts. State- 
of-the-art detection techniques and instru¬ 
mentation will be developed to measure the 
particle environment, as rides become 
available. Dosimeters will be flown on rides 
of opportunity, such as DMSP, to verify 
present flux models. A capability to predict 
dosage/depth relationship for any satellite 
orbit will be developed. Finally, materials 
will be exposed to electron and ion beams in 
a joint effort with RADC/ET which will 
seek to understand the damage mechanism 
in microelectronics. 

Long Duration Exposure: Trapped 
proton fluxes are not well determined, and, 
in fact, long term stability is not yet estab¬ 
lished. While some measurements indicate a 
factor of 2 stability over 10-year periods, 
many measurements indicate either wild 
fluctuations, instrument inaccuracies or 
both problems. To predict false signal rates 
and radiation damage to electronic devices 
operated in space, the differential energy 
spectrum of protons greater than about 1 
MeV must be known to an accuracy of better 
than a factor of 2 throughout the radiation 
belt. Unfortunately, in the 1 to 10 MeV 
energy interval the inner zone proton fluxes 
are almost unknown because of background 
problems. For higher energies great uncer¬ 
tainties still exist and, in general, only inte¬ 
gral energy spectral data are available. 

An exposure package has been designed 
to obtain measurements of trapped proton 
fluxes utilizing the NASA Long Duration 
Exposure Facility (LDEF). The objective 
of this experiment is to perform detailed 
differential energy spectral measurements 
of trapped protons integrated over the six 
month LDEF lifetime. In addition, the 
heavy ion component will be measured and 
neutron intensities determined. Total dose 
will be measured and samples of bubble 
memories will be exposed to determine any 
adverse radiation damage effects. 

Although the basic techniques are similar 
to those used in the 1960s to obtain trapped 
proton fluxes from Air Force recoverable 
satellites, it has been necessary to develop 


proton sensitive plastic detectors capable of 
withstanding the six-month exposure 
planned for the Long Duration Exposure 
Facility. Early experimental designs con¬ 
sisted of shielded emulsions with narrow 
cylindrical openings to allow trapped pro¬ 
tons to enter. The recent discovery of the 
CR39 plastic detector opens up the possibil¬ 
ity of a new solution to this problem. 

Four cubical containers will be provided 
in which passive radiation detectors can be 
arranged and oriented to best detect mir¬ 
roring trapped protons as the LDEF passes 
through the South Atlantic Anomaly. Three 
of these containers will be spaced around 
the LDEF and one placed on the bottom 
(earth) side. 

The experiment is passive so that no 
power or signals are required. Thermal con¬ 
trol is provided by a white external coating 
and black internal coating. Some manipula¬ 
tion of thermal coupling of the payload to 
these surfaces will be performed to avoid 
temperature excursions above 38 C. The 
passive radiation detectors - nuclear emul¬ 
sions, plastics, thermoluminescent dosi¬ 
meters and activation samples - will be 
analyzed following recovery to determine 
proton energy spectra, dose depth relation¬ 
ship and neutron spectra. The bubble mem¬ 
ories will be analyzed for radiation induced 
failure. This experiment offers the potential 
of obtaining the first reliable measurements 
of inner zone trapped protons of 1 to 10 MeV 
as earlier electronic counter measurements 
are uncertain, and the Nuclear Emulsion 
Recovery Vehicle emulsion results were for 
too brief a time interval, in addition to being 
spatially limited. 

Proton Prediction Studios: Proton pre¬ 
diction research is a continuing effort in the 
Space Physics Division. The results of this 
research have been combined into a com¬ 
puter prediction technique used by the 
USAF Air Weather Service Environmental 
Support Facility and the National Oceanic 
and Atmospheric Administration Space 
Environment Laboratory. The techniques 
in use have been very successful for the 



68 


SMS/GOES PREDICTION 



Predicted time-intensity profile for the April 
30. 1976. solar proton event. This prediction is 
for the solar proton sensors on the SMS/GOES 
satellite. 

generation of predictions of solar protons 
responsible for polar cap absorption events 
or for proton fluxes in the 1-100 MeV energy 
range. Significant improvements in the 
accuracy of the forecast were obtained when 
the techniques to predict the slope of the 
solar proton energy spectrum were incor¬ 
porated into the real-time prediction pro¬ 
cedures. 

The solar particle event of 30 April 1976 
was selected for intensive study using this 
proton prediction program. The computer 
program developed for the prediction of 
solar proton events generates predictions of 
solar proton time intensity profiles expected 
after the occurrence of solar flares having 
the distinctive “U-shaped characteristic” in 
the radio emission that has been associated 
with earth-sensed solar proton events. This 
study demonstrated that the technique of 
selectively adapting concepts from experi¬ 
mental and theoretical studies and then 
combining them into a procedure designed 
for practical application appears to be suc¬ 
cessful. 

The predictions for this event were in 
excellent agreement with the satellite data 
observations. The ability to make predic¬ 


tions for the exact energy range measured 
by a specific satellite channel enhances the 
utility of this prediction technique and al¬ 
lows very rapid comparison of the predic¬ 
tion with actual data observations and also 
provides for the possibility of updating the 
forecasts. 

Solar Terrestrial Phenomena Studies: 

The significant solar-terrestrial events from 
20 March to 5 May 1976 have shown that 
even during solar minimum the sun can pro¬ 
duce major interplanetary and terrestrial 
disturbances. A multidisciplinary study of 
solar interplanetary data led to the first 
identification of a solar induced interplane¬ 
tary shock wave at a distance of 9.7 AU. The 
shock wave apparently rapidly decelerated 
up to 2 AU with very little deceleration from 
2-10 AU. 

Solar flare activity during this period was 
associated with several major geomagnetic 
disturbances and several significant solar 
particle increases including a ground-level 
relativistic solar particle event. This event, 
with an unexpectedly hard solar particle 
spectrum, led to a subsequent study indicat¬ 
ing that solar particle events producing 
significant (greater than 0.5 dB) polar cap 



Average shock velocities and type II inferred 
shock velocities. The notation (V,,i), for 
example, refers to the average velocity be¬ 
tween the sun and Jupiter and is plotted mid¬ 
way between these two points. Note the rapid 
deceleration within 1 AU with nearly a con¬ 
stant velocity inferred thereafter. 






69 


absorption during this solar minimum (1975- 
1977) had harder solar particle spectra than 
similar events during the previous solar 
minimum. 

The solar and geomagnetic circumstances 
prior to solar particle increases for the 
period 1970-1972 were studied. A total of 
363 particle events were identified as 
detected near the earth during this period, 
93 of which were proton events with 
energies greater than 19 MeV. Two-thirds 
of these events were confidently associated 
with solar or geophysical sources. It was 
also shown that strong solar magnetic fields 
and interplanetary circumstances appar¬ 
ently significantly influence the propagation 
of energetic particles from the sun to the 
earth. 

A study of the geomagnetic storms and 
solar flares in the years of increasing rolar 
activity, cycles 19 and 20, has shown that of 
the 245 storms in the seven years studied, 
62 percent were flare-associated, 30 percent 
were primarily sequential, arid 8 percent 
remained unassociated. A preponderance of 
the storm-associated flares occurred in the 
western hemisphere of the sun, but the 
most severe storms were associated with 
flares strongly concentrated toward the 
central part of the solar disk. 

HEAO-C Satellite Date: Part of the Space 
Physics Division program involves com¬ 
puting the effects of the geomagnetic field 
on the behavior of charged particles. The 
total problem has no general solution (that 
is, only special cases can be solved), and 
specific effects are obtainable only by 
detailed numerical calculations. The 
HEAO-C satellite, launched by NASA in 
1979, provides an opportunity for an exact 
comparison of experimental measurements 
and theoretical calculations. The experi¬ 
ments on the HEAO-C satellite will observe 
cosmic ray heavy nuclei with hitherto 
unobtainable resolution. There is a phe¬ 
nomena, called the cosmic ray penumbra, 
that has been theoretically predicted for 
many years, but never actually measured 
because the measurement techniques were 


not sufficiently accurate and precise. This 
effect predicts that the geomagnetic field 
will "break up” the flux of high energy 
cosmic ray particles travelling through the 
geomagnetic field into fine details of allowed 
and forbidden energies. The in-house pro¬ 
gram involves computing the theoretical 
geomagnetic cutoff effects for the HEAO-C 
satellite orbit. 

P7&-1 Electrostatic Analyzers: Electro¬ 
static analyzers designed to collect data on 
electrons in the auroral zones, particularly 
during magnetic storms and substorms, 
have been integrated into Air Force satel¬ 
lite P78-1. The results will be correlated 
with data from other sources and used to 
improve existing substorm models. 

The experiment consists of four electro¬ 
static analyzers looking in two different 
directions. They perform a differential 
energy analysis of electrons with energies 
from 50 eV to 20 keV, producing a 16-point 
spectrum for each look-direction every 256 
msec. The detectors are mounted so that all 
pitch angles will be sampled with each revo¬ 
lution of the satellite. 

The satellite is in a sun-synchronous polar 
circular orbit along the noon-midnight 
meridian. Since substorms occur most fre¬ 
quently and most intensely in this region, 
good substorm data should be acquired. 

Interplanetary Scintillation Maea uro- 
mante: This study investigated the po¬ 
tential of interplanetary scintillation 
measurements to predict geomagnetic 
storms. 

A number of USAF systems are sensitive 
to environmental perturbations associated 
with the phenomenon generally known as 
the "geomagnetic storm." The current 
techniques used to predict geomagnetic dis¬ 
turbances are not reliable for long-time pre¬ 
dictions (of the order of days). 

The solar disturbances that ultimately 
cause geomagnetic storms at the earth are 
essentially unpredictable. The solar initi¬ 
ated phenomenon (interplanetary shock 
wave) propagates from the sun to the earth 
in a time period that ranges from 1 to 4 days. 



70 


depending on the type of disturbance. How¬ 
ever, the phenomenon cannot be observed 
directly and its existence must be inferred 
from other measurements until it is actually 
observed by an interplanetary space vehicle 
or arrives at the earth. A new technique of 
monitoring the signals from discrete stellar 
radio sources shows promise of being a 
ground based remote probe of the inter¬ 
planetary medium. Microscale (greater 
than 500 km) irregularities in the electron 
density component of the solar wind cause 
small angular diameter stellar radio sources 
to fluctuate, typically at a rate of about once 
per second. Variations which these inter- 
planetary scinti'lations impress on the radio 
noise from stars may indicate turbulence in 
the solar wind and, hence, shocks propaga¬ 
ting from the sun through the inter¬ 
planetary medium. 

The results of the study indicate that the 
interplanetary scintillation technique has 
the potential of predicting when solar ini¬ 
tiated disturbances will intercept the earth 
and cause a geomagnetic storm. 

Analysis of the available data indicates 
that at the 34 MHz frequency the peak 
activity precedes (on a statistical basis) 
maximum geomagnetic activity by 3.0 ± 1.7 
days. However, the study also showed that 
other phenomena can result in enhance¬ 
ments in the interplanetary scintillations 
amplitude. For example, interplanetary 
scintillations are also correlated with solar 
wind density enhancements (which gen¬ 
erally do not cause geomagnetic storms) as 
well as with turbulent plasma (which is 
associated with geomagnetic storms). One 
conclusion of this study is that whereas the 
interplanetary scintillation amplitude data 
can indicate a potential geomagnetic dis¬ 
turbance, the sc it wind velocity (derived 
from another type of interplanetary scintil¬ 
lation data) is essential to predict when the 
turbulent plasma may intercept the earth 
and cause this geomagnetic disturbance. 


LOW ENERGY PLASMA AND 
ELECTRIC FIELD STUDIES 

Almost all Air Force communication and 
surveillance satellites must function within 
the earth’s ionosphere-magnetosphere 
system, at altitudes from 200 km up to many 
earth radii. These systems need reliable and 
predictable RF propagation. However, the 
plasma in these regions, especially in the 
auroral and polar regions, is constantly 
changing. 

The changes in the plasma are caused by a 
number of mechanisms. One important 
mechanism is the flow of energetic charged 
particles from the sun, the solar wind, which 
distorts the dipole configuration as the solar 
wind changes directly affect the morphol¬ 
ogy of the plasma in the ionosphere- 
magnetosphere region. The exact magnetic 
field configurations associated with changes 
in the plasma are not yet fully determined 
and one major effort of the investigation is 
to determine the electric and magnetic field 
fluctuations which nre signatures of partic¬ 
ular changes in plasma morphology. 

One major impact on Air Force sytems 
caused by the plasma variations is the devia¬ 
tion and scattering of RF ray paths caused 
by large scale and small scale density grad¬ 
ients in the ionospheric thermal plasma. The 
prediction of these gradients and of the 
plasma density irregularities they may form 
is being studied by in situ satellite meas¬ 
urements of the plasma and ambient electric 
fields together with simultaneous ground 
based measurements. In recent years, the 
emphasis in this kind of study has partly 
shifted from the statistical study of a single 
parameter over an extended period to the 
study of individual events such as auroral 
substorms with the simultaneous measure¬ 
ment of many parameters. 

High Altitude Electron Temperatures: 

In spite of the large number of spacecraft 
flown in the past twenty years, the altitude 



71 


region from about 300 km up to about 10,000 
km above the earth is relatively unexplored. 
Satellites with highly eccentric orbits pass 
rapidly through this altitude range and 
satellites investigating the neutral atmos¬ 
phere and topside ionosphere are usually in 
orbits whose apogees are less than 300 km. 

The Air Force S3-3 satellite, launched in 
July 1976 into a polar orbit, with a perigee 
below 300 km and initial apogee of 8000 km, 
has given an opportunity to carry out a 
systematic survey of thermal energy 
electrons up to 8000 km. Due to the low 
electron densities above about 3000 km (less 
than a thousand per cubic centimeter), the 
local-time coverage of this survey has been 
limited to within a few hours of the dawn- 
dusk meridian. When the orbit is in this 
local-time configuration, the electron 
sensor, which is mounted on a boom parallel 
with the spin axis, is in the shadow of the 
spacecraft. This eliminates the production 
of photoelectrons at the outer surfaces of 
the sensor and allows the measurement of 
ambient electrons down to densities of a few 
hundred per cubic centimeter. 

Two distinct features of the thermal 
electrons in the 3000 km to 8000 km altitude 
range have been noted in these data. The 
first is that in the region of closed magnetic 
field lines (the “plasmasphere”) there is 
little detectable change of electron temper¬ 
ature along a given field line as long as both 
ends of the lines are sunlit at approximately 
300 km altitude. However, the temperature 
increases with increasing invariant latitude 
within the plasmasphere. 

The second phenomenon noted is a sharp 
electron temperature gradient with values 
on the order of 0.4 degrees K per kilometer 
along the open magnetic field lines in auroral 
and polar regions. Since magnetic field lines 
are close to vertical throughout auroral and 
polar regions this field aligned electron 
temperature gradient has a vertical com¬ 
ponent. 

Thus, despite the different magnetic field 
geometries in the plasmasphere and at 
higher latitudes, the observations show that 


in both regions electron temperature in¬ 
creases radially outward on the dayside of 
the earth in the 3000 km to 8000 km region. 
This implies a net downward flux of heat 
into the ionosphere, and since at least part 
of this heat flux is due to solar induced 
photoelectrons it forms a near constant con¬ 
tribution to the heat balance of the dayside 
ionosphere. 

Ionospheric Plasma Trough: The iono¬ 
spheric plasma trough is a major feature at 
middle latitudes and has been investigated 
since it was first identified in the mid 1960s. 
It occurs with varying frequency at all local 
times and all seasons. It can have a width of 
3 to 20 degrees latitude, and within the 
trough the density of the ambient thermal 
plasma may be reduced by a factor of 50 or 


A 



Electron temperatures obtained from spheri¬ 
cal gridded sensor flown on Air Force satellite 
S3-3. Values are close to 5700 K throughout 
the altitude range 4800 km to 8000 km along 
closed magnetic field lines. 


more. Because of the ionospheric plasma 
density depletion in the trough, and because 
of the steep horizontal density gradients of 
its poleward and equatorward boundaries, 
radio signal propagation across the trough 
region is sometimes severely degraded as 
the morphology of the trough responds to 
solar-geophysical activity. 







72 


Measurements of trough occurrence fre¬ 
quence and morphology have been made 
using several thousand orbits of data from 
instruments designed by the Electrical 
Processes Branch and flown on the INJUN 
5 and ISIS I NASA satellites. In addition to 
statistical information on trough width, 
depth and location, frequency of occurrence 
data for the full twenty-four hours of local 
time was determined for the first time. 
Previous studies have only indicated occa¬ 
sional observations of the trough on the 
dayside of the earth where solar UV pro¬ 
duces sufficient local ionization in the top¬ 
side ionosphere to mask the presence of a 
trough at altitudes below about 1500 km. 

Two distinct troughs were frequently 
identified on the dayside above about 1500 
km. One trough is located at approximately 
the location of the plasmasphere as is the 
trough observed at other local times. Within 
about three hours of local noon, however, a 
second trough is seen at high latitudes. It is 
this trough which has been reported previ¬ 
ously from total ion density observations at 
low altitudes. It is located at the equator- 
ward edge of the cusp region. This is the 
region on the dayside of the earth where the 
earth's magnetic field lines have direct ac¬ 
cess to the magnetopause. Energetic 
particles precipitating down the field lines 
from the magnetosphere cause the ioniza¬ 
tion which is observed as the poleward wall 
of the trough. 


Satellite E teethe Ftekl M —uramw i ta : 

An electric field sensing system developed 
by the Electrical Processes Branch was 
flown on the Air Force S3-2 satellite and has 
provided several thousand orbits of good 
quality electric field data. 

One specific study using this data, in com¬ 
bination with data from other AFGL in¬ 
struments on this satellite, has been the 
identification in the ionosphere, close to the 


midlatitude trough, of very intense North- 
South electric fields with values as high as 
280 mV/m. These fields are generally ob¬ 
served at times of auroral substorm activity 
and are located close to the current sheets 
associated with auroral arcs. The electric 
field region itself is located slightly equa- 
torward of these current sheets, and very 
close to auroral optical emissions observed 
simultaneously. 

Spacecraft — Plasma Interaction: The 

interaction of a spacecraft with the iono¬ 
sphere or magnetosphere plasma causes 
two classes of problems affecting both Air 
Force operational use of satellites and the 
acquisition of scientific data needed to 
better understand plasma phenomenology. 
As noted earlier, a combination of solar 
illumination, energetic particles and a low 
density ambient plasma can cause the gen¬ 
eration of kilovolt potential differences 
between a satellite and its surroundings or 
between different parts of a satellite. 

At altitudes below 1000 km, the charging 
problem is less severe but the higher am¬ 
bient ion and electron densities cause a 
second class of problems affecting scientific 
measurements in particular. 

This arises from the ion “sheath” which 
builds up around a conducting or partially 
conducting body immersed in a plasma. The 
sheath forms when positive ions are drawn 
toward the spacecraft which generally 
acquires a negative potential because of the 
high random thermal velocity of the elec¬ 
trons in the plasma. The ion sheath forms an 
electrostatic screen between the plasma and 
the negatively charged spacecraft to pre¬ 
vent further attraction of electrons. The 
exact resting voltage of the spacecraft and 
the dimensions of the ion sheath are func¬ 
tions of many parameters including space¬ 
craft velocity and dimensions, and ion and 
electron densities and temperatures. The 
ion sheath greatly interferes with scientific 
measurements of the undisturbed ambient 
plasma especially when these are concerned 
with the thermal plasma where typical 
particle energies are on the order of a few 


73 


electron volts at most. This is frequently less 
than the potentials acquired by the space¬ 
craft. This interaction between the space¬ 
craft and its surroundings can also generate 
wave phenomena in the ambient plasma. 

The geometry and electrical character¬ 
istics of the sheath have been studied in the 
past mainly with the object of determining 
its effect on data from scientific sensors on a 
specific satellite. To do this, many simplify¬ 
ing assumptions were made. A rigorous 
model of the interaction between a shaped 
conducting body and the ionosphere- 
magnetosphere plasma does not yet exist. 
In the Space Shuttle era, however, struc¬ 
tures will be assembled, initially in the 100 
km to 500 km altitude range, which will be 
significantly larger than present spacecraft. 
They will have dimensions on the order of 
one hundred meters or more, and a quanti¬ 
tative description of the interaction be¬ 
tween such a structure and the plasma is 
urgently needed. Until such a model is 
produced, it is probable that problems due 
to current flows within structures, RF in¬ 
terference, and electrical discharges be¬ 
tween docking spacecraft will impede 
steady progress toward the establishment 
of operational space structures during the 
shuttle era through the mid-1990s. 

A simplified study of sheath structure 
was carried out using data from the ion and 
electron sensors built by the Electrical 
Processes Branch and flown on the Air 
Force S3-2 satellite. The data used con¬ 
sisted of thermal electron density and 
temperature, and spacecraft potential, all 
obtained from a spherical gridded sensor 
mounted on a 1.2 meter boom parallel with 
the spacecraft spin axis, together with 
positive ion currents flowing to two arrays 
of planar aperture ion sensors mounted on 
the surface of the satellite. Once during each 
20-second spacecraft rotation each of the ion 
sensors faced into the “ram" direction, and 
the ion current measured at this time was 
taken as proportional to the ambient ion 
density. One-half rotation later, the current 
is a measure of the depletion of positive ions 


WAKE CURRENT / AMBIENT CURRENT 



Comparison of the ratio of satellite wake to 
ambient currents and the ratio of satellite size 
to Debye length. The wake current decreases 
relative to the ambient current when the satel¬ 
lite size is greater than approximately 40 times 
the Debye length. 

caused by the passage of the satellite 
through the plasma. 

The ratio of wake to ambient currents was 
taken as an indication of the relative dis¬ 
turbances to the plasma caused by the 
satellite. This ratio was determined over a 
range of values of three parameters. These 
were: the spacecraft potential with respect 
to the plasma; the relative velocity of Hu 
spacecraft compared to the mean ion 
thermal velocity, and the ratio of the m^jor 
dimension of the satellite to the Debye 
“screening” length of the ambient plasma, 
which is a function of electron temperature 
and plasma density. 

No significant correlation was found in 
the data set between the current ratios and 
spacecraft potential. Although some change 
was noted as the ion mean thermal velocity 




increased, the major dependence, at least in 
the data available for this study, is with the 
ratio of satellite size to Debye length. In 
practice, this means that the relative de¬ 
pletion of positive ions in the wake of a 
spacecraft decreases as the Debye length 
increases. In the ionosphere for a satellite 
with dimensions of a few meters this will 
occur at about 500 km altitude. Together 
with the absence of correlation of ion and 
wake currents with spacecraft potential and 
the slight effect noted with changes in mean 
ion thermal velocity, this means that the 
electrical conditions near the surface of a 
spacecraft are determined largely by the 
relation of its dimensions to the local plasma 
Debye length. 

S3-2 Satellite Data: Data from the S3-2 
satellite are being utilized to study the near 
earth space environment in the polar 
regions, regions subject to intense current 
systems, standing shock waves, strong cur¬ 
rent streams, and magnetic substorms. 
Geophysical conditions in this region can 
vary drastically both with time and dis¬ 
tance. Approximately 18 months of data 
from the S3-2 satellite have been digitized 
while selected events were concurrently 
analyzed. 

On 11 January 1976 the Air Force satellite 
S3-2 passed over the auroral oval within ten 
minutes of the DMSP passage over the same 
regions, thus allowing a comparison be¬ 
tween the DMSP picture of the auroral oval 
with the near-coincident S3-2 measure¬ 
ments of electron flux, thermal plasmas, 
plasma bulk motions, magnetic fields and 
electric fields. The continuous aurora 
(towards the equator) occurred in the region 
of downward field-aligned currents, with a 
low intensity of electron flux; discrete 
auroral arcs occurred in the region of up¬ 
ward ilea'-aligned currents (with the 
brightest ac toward the poleward edge) 
where th*- electron flux reached a value as 
high e < 10" electrons/cm--sec-ster. From 
analysis of the bulk plasma flow, AFGL 
scientists determined that the downward 
current was carried by thermal electrons 


and the upward current by precipitating 
electrons. The electric field was northward 
directed over the regions of current except 
near the most intense currents at the visible 
area. In this region there are indictions of a 
component of the electric field parallel to the 
magnetic field where the current is down¬ 
ward, and anti-parallel where the current is 
upward. 



S3-2 satellite experiment locations. The 
gridded electron sensor, at the end of a 1.2- 
meter boom, measured electron density, 
electron temperature, and spacecraft poten¬ 
tial. The planar sensor packages on the space¬ 
craft surface measured positive ion currents. 
The spin axis of the satellite is also shown. 


SPACECRAFT CHARGING 
TECHNOLOGY 

Many Air Force communications satel¬ 
lites are in geosynchronous orbit for maxi¬ 
mum efficiency. At the altitude of geo¬ 
synchronous satellites (about 26,000 miles 
or 6.6 earth radii), the earth’s space envi¬ 
ronment electrically charges some of these 
satellites and can degrade their per¬ 
formance. 

The problem which the Spacecraft Charg¬ 
ing Technology Project addresses is to 
understand the complex interaction be¬ 
tween a satellite and the plasma environ¬ 
ment at geosynchronous orbit. 

During a magnetospheric substorm, a 
satellite wrapped in its thermal insulation 
blanket is essentially a capacitor immersed 
in a high temperature plasma. Secondary 
emission, photoelectron emission, and the 
ambient thermal plasma all contribute to 
the satellite’s net potential. Anisotropies in 
the satellite’s plasma sheath, created by 


! 

A 

f 



?5 


spin, velocity, and shadowing, complicate 
the interaction and influence the charge 
balance. Shadowing of the spacecraft allows 
a high negative potential on the dark side of 
the spacecraft, while on the sunlit side, the 
potential is near zero. When sufficient 
voltages occur, current discharges which 
produce electromagnetic interference can 
follow. The electromagnetic interference 
can cause circuit upset or satellite failure. 

The importance of spacecraft charging 
effects on satellite performance was only 
recently recognized. An interdependent Air 
Force Systems Command (AFSC) and 
National Aeronautics and Space Admini¬ 
stration (NASA) space technology program 
was form ed to investigate spacecraft charg¬ 
ing. AFGL’s Spacecraft Charging Tech¬ 
nology Project is a key element of this in¬ 
terdependent AFSC/NASA technology 
program. In the project, we model the 
spacecraft charging phenomena, define the 
geosynchronous plasma environment, and 
develop techniques for active control of 
satellite potential. The technology base 
derived from these efforts is immediately 
applicable to continuing ;jid planned Air 
Force space systems. The goal is to support 
SAMSO (Space and Missile Systems Organ¬ 
ization) in developing a satellite test specifi¬ 
cation and a design criteria for spacecraft 
charging. 

SCATHA: The SCATHA (Spacecraft 
Charging at High Altitudes) satellite is an 
integrated satellite experiment that is used 
to measure the characteristics of the space¬ 
craft charging phenomena, to determine the 
response of the satellite to the charging 
process, and to evaluate corrective tech¬ 
niques. The SCATHA satellite was 
launched from the Eastern Test Range in 
January 1979. SCATHA has an equatorial 
orbit with an apogee of 7.7 earth radii and a 
perigee of 5.5 earth radii. 

The 13 experiments on SCATHA are 
provided by AF, Navy, NASA, DNA, 
industry and university groups. There are 
engineering experiments to measure sur¬ 
face potentials and the electrical effects of 


spacecraft charging on satellite surface and 
subsystems. Environmental experiments 
measure the characteristic fields and par¬ 
ticle fluxes. Two of the AFGL experiments 
fall into this latter group, the Thermal 
Plasma Analyzer and Rapid Scan Particle 
Detector. AFGL also provided an electron 
beam system and a positive ion beam 
system. These systems will be used to 
develop techniques to actively control 
spacecraft charging. The engineering, envi¬ 
ronmental and charge control experiments 
were selected to work in concert and, thus, 
relate cause and effect in spacecraft charg¬ 
ing. 

Ion and Electron Baam Emittara: The 

study of spacecraft charging requires the 
ability to control as many of the variables as 
possible. One way to do this is to charge the 
vehicle artificially, at a known rate. To do 
this, AFGL has developed two experiment 
packages for the SCATHA satellite. 

The Satellite Electron Beam System is an 
electron beam source, and the associated 
electronics for controlling and measuring 
the emitted current. Under ground control, 
the current and energy of the emerging 
electron beam may be varied to produce a 
range of positive spacecraft charge. 



SCATHA Satellite Poeitive Ion Beam 
System. 

To investigate the effects of positive 
charge emission, the Satellite Poeitive Ion 
Beam System was developed and in¬ 
corporated into the satellite. Capable of 
emitting either electrons or positive ions or 





76 


both, this payload uses non-contaminating 
xenon gas to produce a wide dynamic range 
of useful charging rates and energies. 

The two packages together provide the 
ability to charge the satellite to a positive or 
negative potential, to discharge the charged 
satellite, and to hold the satellite in an 
uncharged condition. 

Rapid Scan Particle Detact or: The 
Rapid Scan Particle Detector measures the 
flux of electrons and ions incident to the 
spacecraft in directions perpendicular and 
parallel to the spin axis of the satellite. 
These measurements enable researchers to 
determine the number, density, temper¬ 
ature, and bulk flow of the plasma and the 
relationship of these quantities to the occur¬ 
rence of spacecraft charging. In addition, 
the Detector is used to monitor the response 
of 'his plasma to the operation of the Elec¬ 
tron and Positive Ion Beam System and to 
provide a synoptic survey of the plasma 
characteristics as a function of local time, 
altitude, and geomagnetic conditions. 

Space Environment Specifications: 
AFGL has undertaken an ambitious pro¬ 
gram having as its ultimate goal the speci¬ 
fication of ambient space environment in 
which military operations take place. As the 
first phase of this effort, a preliminary, but 
detailed, specification of the geosynchro¬ 
nous environment h is been prepared for 
inclusion in the Military Standard on Space¬ 
craft Charging. In conjunction with this 
specification, a simple analytic model cap¬ 
able of predicting the status of the geo¬ 
synchronous environment was developed 
and incorporated into the GWC and NOAA/ 
SELDADS systems. It is planned to update 
and further define these results with data 
from the SCATHA satellite in 1979 and 
lu80. Comprehensive models are also being 
developed of the near-earth and polar 
regimes as these are also regions of poten¬ 
tial impact on military systems. 

Coiflpirtji I^^^J : A theoretical 

description of the process of spacecraft 
charging by magnetospheric substorm 
plasmas is being prepared in the form of a 


computer code called SCATHCAP 
(SCATHA Charging Analyzer Program). 
The SCATHCAP code performs a dynamic, 
fully three-dimensional simulation of elec¬ 
trostatic charging processes for an object in 
space or in a ground test chamber envi¬ 
ronment. In particular, the code predicts 
surface potentials on spacecraft, identifies 
high-field areas of possible discharge sites, 
predicts response to environmental change, 
predicts and interprets particle detector 
response and assesses the effects of particle 
emission from active control devices. In the 
code, the spacecraft is represented by a 
finite element method, each element being a 
cube or a slice of a cube. The computations 
are performed in nested meshes, with an 
inner mesh size of 16 x 16 x 32 cells. Each 
successive mesh has double the mesh spac¬ 
ing, and as many as seven meshes have been 
employed. A different material may be 
specified for each element surface, so that 
properties such as secondary emission, 
backscattering, photoemission and con¬ 
ductivity may be taken into account for each 
cell. The surface resolution of spacecraft 



The thermal energy positive ion and electron 
sensors, mounted at the end of the 3-meter 
boom which projects in the spin plane of the 
spacecraft. 



77 


detail is about 10 cm. The code calculates 
particle trajectories in sheath fields as well. 
The SCATHC AP code is the most advanced 
satellite charging code available and will be 
extensively employed for the analysis of 
spacecraft charging and active control of 
future satellite systems, for studies of 
contamination, and for the analysis of the 
response of particle detectors on spacecraft. 

THE A“G! MAGNETOMETER 

NF rV'i. * 

Ar'Gl.’s network of magnetometer 
stations, which extends across the contin¬ 
ental United States, monitors the earth’s 
magnetic field continuously. Each instru¬ 
mented data collection station operates 
continuously and automatically, unattended 
except for routine maintenance. Data from 
each station are returned in real time on 
commercial voice-grade communication 
circuits to a single data acquisition station 
located at Hanscom AFB, Massachusetts. 
The data acquisition station processes, re¬ 
duces, and displays the data in real time, 
and stores processed data in a permanent 
file for subsequent analysis. All the facilities 
are dedicated to the program, so essentially 
uninterrupted operation over an extended 
time period is possible. 

The magnetometer network has several 
important features. The geographic dis¬ 
tribution of stations makes it possible to 
obtain a detailed picture of the magnetos- 
pheric currents which cause magnetic dis¬ 
turbances. The synchronization of stations 
and the rapid sampling rate permit high 
time resolution measurement of both 
strength and direction of the earth's mag¬ 
netic field. Identical instruments at each 
station produce directly comparable data. 
The ability of the stations to operate with¬ 
out interruption for several years allows 
continuous monitoring of the magnetic field. 
The automatic real time processing, stor¬ 
age, reduction, and display of the combined 
data allow operational units to make use of 
the information. Finally, the network can be 



TPA * 


Geographical locations of the stations in the 
AFGL magnetometer network. 

expanded or operated in conjunction with 
networks established by other organiza¬ 
tions. 

The network now includes seven stations. 
Five are spaced across the northern United 
States at about 55 degrees N corrected 
geomagnetic latitude, while two others 
space the southern United States at about 
40 degrees N corrected geomagnetic lati¬ 
tude. The principal instruments at each data 
collection station are triaxial fluxgate and 
searchcoil magnetometers. The sites are 
provided with electrical power, a voice- 
grade communications line for data trans¬ 
mission, and telephone service. 

The data-conditioning circuitry at each 
data collection station accepts instrument 
data and converts them to a signal which can 
be transmitted by the data communications 
link. The process includes sampling of out¬ 
put data, converting to digital form, order¬ 
ing into a standard frame format, coding for 
error-rate improvement, and outputting as 
a serial bit stream. A microprocessor with a 
stored program controls all of these func¬ 
tions. 

The data acquisition station has two prin¬ 
cipal functions: network control and data 
processing. Network control is accom¬ 
plished through the generation of a net¬ 
work-control signal which is transmitted 







78 


continuously on the outlink of the data 
communications link. The inlink is used for 
data return, time-shared by all of the data 
collection stations, each of which transmits 
a frame of digitized data in a programmed 
sequence. Each data collection station re¬ 
sponds according to instructions contained 
in the signal, which synchronizes the taking 
of data samples by the scientific instruments 
and the transmission of these data at the 
proper time. 

An excellent data base for the year 1978 
has been archived, and fulltime operation is 
continuing. The full complement of seven 
stations was completed in late 1977, but 
data archiving began in 1976. The data are 
now sufficient to support intensive efforts in 
analysis and scientific study. 

Two objectives of the network are the 
specification and prediction of the state of 
the magnetosphere and the understanding 
of magnetospheric processes, particularly 
as these affect the performance of military 
systems which must operate in the space 
environment at the base of the magneto¬ 
sphere. Since the interior field of the earth is 
constant, the surface field measured by the 
network is a direct reflection of magneto- 
spheric processes. The wide geographic 
coverage affords part of the three- 
dimensional view needed to discover the 
sources and propagation directions of dis¬ 
turbances. The use of simultaneous space¬ 
craft measurements in conjunction with the 
network data provides an even more power¬ 
ful method for attacking major problems in 
the magnetosphere. 

Several problems are now being studied. 
Sudden commencements, which result from 
compression of the magnetosphere by a 
shock wave from a solar flare, are usually 
precursors to magnetic storms and can 
serve in the prediction of the space envi¬ 
ronment; the network data permit these to 
be detected in real time, and their propaga¬ 
tion near the earth can be studied in detail. 
Geomagnetic pulsations reflect specific 
processes occurring at distant locations; for 
example, the onset of substorms is ac¬ 


companied by the Pi2 type, which can there¬ 
fore serve as another prediction indicator. 
An overall activity index can be determined 
in real time from the network data, so a 
realtime knowledge of the condition of the 
magnetosphere is possible. To aid in these 
studies, a variety of analytical techniques 
has been developed; among these are band¬ 
pass filtering, nonlinear maximum-entropy 
power-spectral analysis, and computer¬ 
generated plots of the data and reduced 
parameters. 

IONOSPHERIC DYNAMICS 

Two regions of the global ionosphere 
routinely exhibit a disturbed character: the 
high latitude ionosphere, poleward of ap¬ 
proximately 55 degrees corrected geo¬ 
magnetic latitude and the equatorial iono¬ 
sphere, equatorward of approximately 20 
degrees geomagnetic latitude. 

These regions are characterized by the 
routine occurrence of ionospheric irregu¬ 
larities, strong horizontal electron density 
gradients, and rapid changes in the hori¬ 
zontal and vertical electron density distri¬ 
butions. These phenomena arise from a 
variety of sources, such as ionospheric cur¬ 
rents, ionospheric and magnetospheric 
electric fields, neutral air motion and ener¬ 
getic particle precipitation at high latitudes. 

The disturbed ionospheric regions affect 
radio wave propagation over a large part of 
the radio frequency spectrum, from very 
low frequencies (3 to 30 kHz) to super high 
frequencies (3 to 30 GHz). Many Depart¬ 
ment of Defense communication and sur¬ 
veillance systems operate in or through 
these disturbed regions. 

The Space Physics Division uses a unique 
tool in the investigation of the disturbed 
ionosphere and its impact on Air Force 
systems; an NKC-135 jet aircraft, the Air¬ 
borne Ionospheric Observatory, instru¬ 
mented for auroral and ionospheric re¬ 
search. The instrumentation consists of 
sophisticated ionospheric sounders, re¬ 
ceivers covering a large part of the radio 


79 


( 


i 


i 




t 

\ 



wave spectrum, photometers, spectro¬ 
meters, all-sky cameras and an all-sky 
photometer. This combination of experi¬ 
ments is the basis for many studies that 
describe in detail the environment and the 
environmental effects on Air Force sys¬ 
tems. 

Equatorial studies, centered around the 
aircraft and the all-sky photometer, reveal a 
dynamic and structured equatorial airglow 
pattern. The airglow features identify the 
site of ionospheric irregularities that cause 
scintillations on satellite communications 
links. 

The optical response of the atmosphere to 
the particle precipitation at high latitudes is 
the aurora. The understanding of the coup¬ 
ling of ionospheric, magnetospheric and 
auroral phenomena has progressed con¬ 
siderably over the last decades, and auroral 
measurements by the Airborne Ionospheric 
Observatory have been instrumental in 
achieving this increased understanding of 
the high-latitude ionosphere and its impact 
on Air Force systems. This understanding 
is being used to assist in specifying the en¬ 
vironmental impact on the operation of the 
evolving CONUS Over-the-Horizon Back- 
scatter Radar System. 

Quantitative studies are closely aligned 
with the experimental investigations. 
These studies involve theoretical modeling 
of the E-layer electron density profiles and 
work to derive ionospheric parameters from 
aurora and airglow emissions. These latter 
efforts are directed toward large-area iono¬ 
spheric mapping by optical techniques. 

To enhance the results from the limited 
number of airborne studies, continuous 
observations of the high-latitude ionosphere 
are conducted at the Goose Bay Ionospheric 
Observatory. These observations are used 
to develop remote sensing techniques to 
provide a routine input into the Air Weather 
Service Space Environmental Support 
System and to permit the classification of 
specific airborne measurements with 
respect to the general behavior of the 
ionosphere. 


GOOSE BAY IONOSPHERIC 
OBSERVATORY 

The AFGL Goose Bay Ionospheric Ob¬ 
servatory (GBIO) plays a significant role in 
defining the effects of the high latitude ion¬ 
ospheric environment on defense systems 
while also contributing to Air Force opera¬ 
tions. Located at 65 degrees corrected 
geomagnetic latitude, GBIO has a geo¬ 
physically significant location; during night¬ 
time, it is in the proximity of mtyor high 
latitude ionospheric features such as the 
auroral E-layer, the F-layer poleward 
trough wall, the equatorial boundary of the 
auroral ionosphere, and areas of ionospheric 
irregularities and auroral absorption. These 
features have large latitudinal gradients 
and distinct boundaries while extending 
over hours of corrected geomagnetic local 
time. The location is suitable for gathering 
research data on these ionospheric dis¬ 
turbances and the motions of the iono¬ 
spheric boundaries. 

GBIO contributes to Air Force operations 
by the acquistion and processing of iono- 
sonde, magnetometer, riometer, total 
electron content, and radio beacon scintilla¬ 
tion data and the communication of the re¬ 
sults to the Air Force Global Weather Cen- 


GEOMONITOR I ON OG RAM PROCESSING 
Goom Boy, Co node. 77-282 


COMPUTE IONOGJUM PCCONSTlTUTEO ©NOGPAM 

r«M %m.^i 

'•00 AST 1107 AST 



On the left is a complete digital ionogram, 
representing 21,600 6-bit characters. On the 
right is a 2,340 character reconstituted ion¬ 
ogram. 




80 



This Defense Meteorological Support Pro¬ 
gram satellite image of the aurora is a dra¬ 
matic example of the relationship of the night 
sector of the auroral oval under very disturbed 
conditions and the experimental Over-the- 
Horizon Radar coverage zone. 

tral in real time. The 414L Over-the- 
Horizon radar system is an ionospherically 
dependent defense system needing data 
from locations such as GBIO. Goose Bay 
vertical incidence ionograms will be dis¬ 
played in real time at the Experimental 
Radar Site in Maine during the System Per¬ 
formance Test. The Goose Bay ionograms 
are important for understanding the per¬ 
formance of the system. GBIO data will also 
be used for the subsequent ionospheric 
specification performed by AFGL and the 
Air Weather Service for the Over-the- 
Horizon Radar System Program Office 
Geomonitor: In the past, AFGL has 
participated in the development of ad¬ 
vanced ionosondes using digital instead of 
analog formats which extend the capability 
of this research tool to operational use. The 
digital format permits real time, automated 


processing but the volume of data is signifi¬ 
cant. Digital techniques for echo recognition 
have been developed which reduce the data 
volume (from 21,600 to 2,340 characters per 
ionogram), prepare the ionospheric data for 
further processing, and simplify data stor¬ 
age and transmission. Analytical methods 
perform detection of the echoes and the 
determination of their virtual height, ampli¬ 
tude, and range spread. For real time appli¬ 
cation, these techniques have been imple¬ 
mented, using a microprocessor, in the 
Geomonitor, now in operation at GBIO. The 
echo detection algorithm detects up to six 
echoes, two from the E-region below 156 km 
and four from the F-region above 156 km. 
Echo verification and accurate virtual 
height measurement are accomplished by 
comparison with a sliding standard pulse. 
The spread, or apparent width in virtual 
height, is also determined for the largest E- 
and F-layer echo. 





1 •(, t,, N "' 

.7,1' LG-- - ‘ -b 







Forty-eight hours of characteristics from the 
Geomonitor at the Goose Bay Ionospheric 
Observatory. The top panel shows the inte¬ 
grated range display from the poleward 
directed backscatter ionosonde. The echo 
amplitudes are normalized for each of 128 
height intervals. The middle panel shows the 
vertical incidence F-region frequency char¬ 
acteristics while the lower panel shows the 
E-region characteristics Frequency char¬ 
acteristics are created by printing the largest 
echo amplitude for all frequencies in each 
region. 










81 


The detected echoes can be recast into the 
format of the original digital ionogram for 
use at a central user site after transmission 
from the remote observing site. These 
reconstituted ionograms are also created by 
the Geomonitor at the observing site for 
verification of proper performance. Almost 
all of the detail of the complete ionogram is 
retained in the reconstituted ionogram, ade¬ 
quate for operational monitoring. 

Spaca Data Communication: Presently, 
observers acquire Space Environmental 
Support System data, process it, and report 
it to the Air Force Global Weather Central. 
An automated system could take data 24 
hours each day at a fraction of the cost of 
observers working 8 hours each day. The 
Geomonitor presently operational at the 
Goose Bay Ionospheric Observatory ac¬ 
quires magnetometer, riometer, radio 
polarimeter, and satellite radio beacon data 
and performs rudimentary processing on it. 
However, the capabilities of the Geo¬ 
monitor cannot be expanded to include the 
automated acquisition, processing, and 
communication of data desired. Further¬ 
more, the Geomonitor was designed for 
real-time analysis of data from the digital 
ionosonde at Goose Bay Ionospheric Ob¬ 
servatory, while digitizing other types of 
data. 

Therefore, work has begun on designing a 
Space Environmental Support System Data 
Communicator which will use existing data 
message formats and communications 
circuits, and which will be retrofitted to 
existing analog sensor systems. The proto¬ 
type is expected to be a versatile, micro- or 
mini-computer based system using 
standard modules assembled to auto¬ 
matically acquire whatever data is taken at 
the particular site, process it and com¬ 
municate it to Air Force Global Weather 
Central over standard teletype circuits. 

The data would be recorded as well as 
transmitted, to expand the research data 
base, and allow quality control. The system 
should be able to automatically answer a call 
from the Space Environmental Support 


77-287,1637 AST 



FREQUENCY, MHl 

An example of how characteristics ami recon¬ 
stituted ionograms could be used in an Over 
the-Horizon radar. The upper picture shows a 
late afternoon midlatitude ionosphere with 
of 8.7 MHz. Radar operation near Goose 
Bay would be by E-layer propagation. How¬ 
ever, the backscatter range characteristic has 
recorded the approach of echo-producing ion¬ 
ospheric features. Below, the reconstituted 
ionogram at <i p.m., after the arrival of the 
echo-producing disturbance. Operation near 
Goose Bay would now be by E-layer propa¬ 
gation. The reconstituted ionograms show the 
radar site w hat the ionosphere near Goose Bay 
is like while the characteristics give warning of 
the approach of a disturbance. 

77-287,1800 AST 


800—1 



S 10 

FREQUENCY, UNi 


System Duty Forecaster at Air Force 
Global Weather Central, who could interact 
with the system as though he were at the 
data collection site. 








Airborne Studies: The AFGL Airborne 
Ionospheric Observatory has the unique 
advantage as an auroral observing system 
of being able to fly westward so as to dwell 
continuously at a fixed local magnetic time 
for as long as 10 hours. Thus, it can observe 
local midnight in the frame of reference of 
the magnetosphere-ionosphere itself, un¬ 
complicated by the passage of local time. 

A number of such case studies have been 
performed, the most extensive of which was 
a 12 hour period which included two isolated 
substorms. For nine of the 12 hours, the 
AFGL Airborne Ionospheric Observatory 
flew so as to remain constantly near local 
midnight, a path which also intersected four 
consecutive passes of the ISIS-2 satellite 
and the fields of view for eight passes of 
DMSP satellites. The simultaneous and 
complementary ionospheric, photometric, 
photographic, magnetic and particle meas¬ 
urements have been used to map and inter¬ 
relate the auroral E- and F-regions, the 
electrojet, and the discrete aurora in the 
oval and polar cap. Where possible, phe¬ 
nomena which are caused by a particular 
type of precipitating particle were identi¬ 
fied. The results were detailed in four 
papers. 

Discrete Auroras Near Midnight: The 

discrete aurora produces sporadic E phen¬ 
omena which interfere with HF propaga¬ 
tion, HF communications, and OTH-B 
surveillance. In addition, the optical emis¬ 
sions from the discrete aurora interfere 
with certain optical surveillance systems. 

The discrete aurora has been studied 
using all-sky camera photographs taken on 
12 extended local midnight flights by the 
Airborne Ionospheric Observatory. 
Photographs were taken at 1 minute inter¬ 
vals during the total of 93 hours with con¬ 
tinuous coverage per flight ranging from 5 
to 9.75 hours. 

A characteristic lifetime of auroral oc¬ 
currence has been defined by this study as 
15 minutes. The significance of this lifetime 
is that it is the same as the characteristic 
duration of plasma flows measured in the 



Geophysical stations supporting the Experi¬ 
mental Radar System tests. 

plasma sheet by satellite. These flows are 
further believed to produce electrostatic 
shock waves which accelerate electrons to 
keV energies, appropriate to produce the 
discrete aurora. Apparently, then, the 
auroral lifetimes are related to the duration 
of these flows. 

Aurora and Auroral E-Layar: The other 
important result was the further definition 
of the continuous (or diffuse) aurora and of 
the auroral E-layer which it produces. 
Earlier work had shown that this aurora 
exists at all local times, is always present, is 
the only aurora in very quiet times, and 
represents most of the energy input into the 
auroral ionosphere. 

This present work has shown that it forms 
a better basis for the positional ordering of 
auroral phenomena than the Feldstein oval 
since the continuous aurora defines the 
position of most of the auroral phenomena in 
the night sector: the discrete aurora is pole- 
ward or overlaps the poleward edge of the 
continuous aurora; the F-layer irregularity 
zone coincides with it; the F-layer trough 
wall is below the equatorward edge; and the 
region of D-region ionization overlaps the 
equatorward edge. 

Auroral E-Roglon Progra m : The 

purpose of this program is to study the 
feasibility of sensing electron density pro¬ 
files for the continuous (or diffuse) aurora by 






83 


satellite measurements of optical emissions. 
The program consists of coordinated rocket, 
satellite, aircraft and ground-based meas¬ 
urements, and a theoretical effort to analyze 
the data. 

The experimental program is planned for 
the winter of 1980-81 at Poker Flat, Alaska, 
and consist s of the following measurements: 
electron and proton energy spectra by sat¬ 
ellite and rocket; volume emission rates by 
selected wavelengths by rocket; electron, 
ion and neutral particle densities by rocket; 
electron and neutral particle temperatures 
by rocket; electric and possibly magnetic 
fields by rocket; electron densities by the 
Chatanika incoherent scatter radar; and 
other ionospheric, geomagnetic, photo¬ 
graphic and photometric quantities by the 
Airborne Ionospheric Observatory and 
ground facilities. 

The theoretical program consists of the 
application of the methods of transport 
theory to calculate most of the experi¬ 
mentally-determined quantities. Experi¬ 
ment and theory can then be compared, and 
the feasibility of determining electron 
density profiles for the auroral E-layer from 
satellite optical measurements assessed. 

High Latitude Auroral Imaging: An All- 
Sky Imaging Photometer, developed under 
a Laboratory Director’s Fund Program, has 
been installed in the Airborne Ionospheric 
Observatory. This instrument provides a 
new capability to monitor auroral emissions 
of importance to ionospheric and magneto- 
spheric processes. Several flights in the 
evening/midnight sector of the auroral oval 
have been completed. Studies are in prog¬ 
ress to relate ground backscatter echoes 
from the Goose Bay Ionospheric Observa¬ 
tory to optical auroral features in an effort 
to correctly interpret the backscatter 
measurements, and thus improve remote 
monitoring of auroral oval dynamics. Ex¬ 
tended flights in the noon sector have pro¬ 
vided the first spectral images of the day- 
side (cleft) aurora. The dynamics of the 
dayside aurora are being investigated to 
establish their relation to auroral substorms 


and Interplanetary Magnetic Field (IMF) 
variations. 

Photodldctron Flux and Optical Emis¬ 
sions: These studies seek to determine to 
what extent altitude profiles of electron and 
neutral densities can be determined by 
remote satellite sensing of optical emis¬ 
sions. 

At the request of SAMSO, AFGL has 
undertaken a program in the remote sens¬ 
ing of daytime electron and neutral density 
altitude profiles at midlatitudes from satel¬ 
lite optical measurements. To do this, a 
sufficiently accurate theory for the photo¬ 
electron flux is needed; once it is known, 
volume emission rates at selected wave¬ 
lengths may easily be calculated. Satellite 
optical emission measurements can then be 
used to determine altitude profile informa¬ 
tion. 

At AFGL, a new approach (combining the 
Boltzmann and Fokker-Planck equations) 
was used to calculate the photoelectror flux 
for the daytime, bottomside ionosphere. 
The self-consistent solution of the combined 
equation led to improved agreement be¬ 
tween theory and experiment for the pho¬ 
toelectron flux at electron energies ranging 
from 1 to 60 eV. 

In the future, these methods will be 
generalized so that properties of the topside 
ionosphere that are of interest to SAMSO 
and the AWS can be studied. 

SIGNAL SCINTILLATIONS 

Irregularities in electron density in the 
ionosphere produce both phase and ampli¬ 
tude fluctuations of signals passing from 
satellites to ground or vice versa. The prob¬ 
lems occur at high latitudes and in the 
region within 20 degrees of the magnetic 
equator. 

Frequencies from 20 MHz to 6 GHz have 
been affected. The study of scintillations as 
a function of latitude and longitude, time of 
day, magnetic conditions, and solar condi¬ 
tions, allows operational systems to real¬ 
istically confront the natural problems they 
encounter. The development of models of 



St 


both the short-term and long-term behavior 
of these irregularities allows engineers to 
develop second generation systems which 
will keep the problems caused by fading to a 
minimum. 

During the past few years, AFGL re¬ 
searchers have concentrated on the equa¬ 
torial irregularity structure since it pro¬ 
duces considerably greater effects. It has 
been established that the nighttime iono¬ 
spheric equatorial irregularity regions 
emerging after sunset develop from bottom- 
side instabilities. A bubble depleted in 
electrons rises from below' the peak of the Fa 
layer (below 250 km) into altitudes ranging 
to 1000 km. Propagation of satellite signals 
through these bubbles leads to severe am¬ 
plitude and phase fluctuations. The bubble 
formation has been studied by a variety of 
methods. 

For the systems designer, the patch 
development, size, duration, and decay 
properties are important. Three campaigns, 
each lasting about two weeks, were 
mounted, one each in October 1976, March 
1977, and March 1978, to investigate 
equatorial irregularities and their effects on 
satellite communication links. Airborne and 
ground-based instruments were used in 
these campaigns. Instruments designed for 
geophysical experiments significantly en¬ 
hanced the scintillation studies. 

An all-sky imaging photometer moni¬ 
tored structures in the 6300 angstrom air- 
glow emission (airglow depletions). These 
airglow depletions are the optical signa¬ 
tures of regions of low density plasma which 
contain the irregularities responsible for the 
plume type echoes received by the 50 MHz 
Jicamarca Backscatter Radar, for spread F 
echoes in ionosondes, and for UHF and 
VHF scintillation. The horizontal extent of 
these regions can be mapped optically, 
complementing other diagnostic tech¬ 
niques. Scintillation measurements of satel¬ 
lite signals were carried out from Ancon and 
Huancayo, Peru, from Natal, Brazil, and 
from Ascension Island, as well as from the 
Airborne Ionospheric Observatory. 


A model of the equatorial irregularity 
patch emerged. The patch is a region of low 
electron density containing irregularities 
with scale sizes ranging from three meters 
to tens of kilometers. These structures 
measure 100-200 km east-west, over 2000 
km north-south across the magnetic 
equator, and extend in altitude from 200 km 
to 800 km. They form after sunset, and then 
move eastward with velocities ranging from 
100-200 meters per second, slowing down 
towards midnight and dissipating in the 
morning hours. This eastward motion of the 
irregularities causes a very clear depend¬ 
ence of the signal fading rate on the aircraft 
heading. Since the drift direction is well 
established, the ratio of the fading rates for 
easterly and westerly courses permits an 
estimate of the drift velocity of the irregu¬ 
larities. Patches have been tracked by the 
aircraft and through ground measurements 
for over 3 hours. The irregularity structure 
and its drift velocity appear stable enough 
over this time span so that the full heading 
dependence can be mapped. 

These banana-like patches usually end 
within 20 degrees of the geomagnetic 
equator. Irregularities over the equator at 



OCOG. 10NWTUOE 
12/13 MMCM t»T» 


Images of the KUO t airflow taken north and 
south of the magnetic equatorduriniithe niifht 
of March 17-IS. 1978. 

600 km map to 200 km altitude in the path 
from Ascension Island to a synchronous 
satellite. The entry point is about 13 de¬ 
grees from the magnetic equator. When the 



85 


irregularities come into the lower F-region, 
they terminate (the tip of the banana). If the 
irregularity extends to altitudes greater 
than 600 km at the equator, the irregularity 
may extend to higher altitudes and latitudes 
away from the equator. 

Signal Statistics of Equatorial Scintil¬ 
lations: The October 1976, March 1977, and 
March 1978 equatorial campaigns provided 
many periods of intense scintillations from 
the Ancon, Peru, station. These have been 
analyzed for signal statistics, i.e., the S 4 
index, auto-correlation function and power 
spectra. In addition, spaced receiver data 
were processed to determine the velocity of 
the irregularity regions from the spatial 
correlation function. Signal statistics as a 
function of time were correlated with the 
passage of irregularity regions through the 
Jicamarca radar. On a typical evening, 
shortly after sunset, the S 4 index, which 
measures the intensity of scintillations, 
shows an abrupt rise at the onset of scintil¬ 
lations and its variations trace the passage 
of one or more irregularity regions through 
the antenna beam. The index often reaches 
or slightly exceeds unity indicating the 
development of a Rayleigh fading distribu¬ 
tion, a characteristic of the most intense 
scintillations. 

The autocorrelation interval is a measure 
of the bandwidth or rate of scintillation. The 
autocorrelation interval was usually low, of 
the order of a few tenths of a second, follow¬ 
ing the onset of scintillations, but could 
rapidly rise to a value of several seconds. 
Generally, the autocorrelation interval was 
lowest during the most intense scintilla¬ 
tions. 

Diversity schemes can reduce the effects 
of fading during a scintillation event by 
combining two signals that are fading inde¬ 
pendently. Most of the diversity improve¬ 
ment is obtained for correlation coefficients 
less than 0.6 when slow multiplicative 
Rayleigh fading occurs and equal signal-to- 
noise ratios occur in both branches of a dual 
diversity system. The autocorrelation data 
indicates that time diversity techniques 


would have to provide delays of a few 
seconds to significantly reduce the effects of 
scintillation. 

Cross correlation data from spaced re¬ 
ceivers on an east-west baseline of 366 
meters showed great variability under 
conditions of intense scintillations, ranging 
from a low of 0.2 (almost complete decor¬ 
relation) to almost unity. A much larger 
spacing would be required to provide ade¬ 
quate decorrelation for space diversity 
MARCH 17, 1977 

AFGL AIRCRAFT 
LES-9 



m 


x 

Ul 



22 23 00 01 LT 

Tracking an irregularity patch by noting scin¬ 
tillations. The patch moves past several 
points. 

under all conditions of intense equatorial 
scintillations. 

The velocity of the irregularity regions 
was also determined from the spaced re¬ 
ceiver data by measuring the time deliy. 
The irregularities move eastward with 




86 


speeds that typically vary from approxi¬ 
mately 50 to 200 meters per second. 

The studies are continuing with emphasis 
on the variation of signal statistics as the 
irregularity patches evolve and decay. 

Auroral Effects: Airborne ionospheric 
and auroral observations have been com¬ 
bined with simultaneous scintillation meas¬ 
urements from polar orbiting satellites. 
This technique proved successful in map¬ 
ping irregularities over large sections of the 
polar region for extended periods, and for 
correlating scintillations with auroral or 
ionospheric structures. 

A high latitude model of scintillation 
activity has been completed. The model is 
limited to providing scintillation fluctua¬ 
tions over the range of invariant latitudes of 
53-64 degrees. It uses long-term data ex¬ 
tending from 2Mi to 6 years. In the model, 
scintillations depend on time of day, day of 
the year, solar flux, invariant latitude, and 
magnetic index. Frequency dependence 
terms and geometrical corrections have 
been added to the model. Data on polar lati¬ 
tudes is still sparse so that a polar term 
could not be developed. Future observa¬ 
tions over Thule are expected to add data to 
complete this study. 

IONOSPHERIC CORRECTIONS 
FOR PRECISION RADARS 

Refraction of radio waves in the normal 
ionosphere, particularly at solar maximum, 
degrades the measurement of precise range 
and bearing. For modem tracking radars, 
such as COBRA DANE and PAVE PAWS, 
refraction effects create errors that exceed 
the required metric accuracy; therefore, a 
correction must be made in real time for 
each radar hit. Analysis demonstrated that 
a simple FORTRAN algorithm within the 
radar processor, based on a three-element 
vector model of the ionosphere, could pro¬ 
vide the equivalent of a fast access look-up 
table for the entire surveillance volume of 
the radar. 

The vector model is calculated off line 
once a month. By removing the monthly 


mean ionospheric effect, it removes 75 per¬ 
cent of the refractive error. Since the re¬ 
quirements for metric accuracy on single 
missions still cannot be met at the peak of 
the day during solar maximum conditions, 
provision has been made for refining the 
correction. This is now done in two ways: 
first, from worldwide ionospheric observa¬ 
tions, the Air Force Global Weather Cential 
determines a daily update factor which 



A contour plot of the difference between the 
monthly average total electron content and 
the actual value during a magnetic storm, 
during the winter, measured by stations in 
eastern North America. The heavy dashed 
line in the upper plot marks the time of great¬ 
est enhancement of the total electron content 
during the first day of the storm. 

matches the monthly mean vector model to 
the current ionosphere; second, using a dual 
frequency range measurement to certain 
satellites, the radar determines a scale 
factor that provides a more precise correc¬ 
tion. With the second technique the radar 
may be able to determine a scaling factor in 
the target area as frequently as every 15 





87 


< 


t 

1 


l 



minutes, and remove 95 percent of the iono¬ 
spheric effect. 

Magnetic Storm Studies: Total Electron 
Content (TEC) studies using Faraday 
polarization rotation data from VHF signals 
transmitted from geostationary satellites 
have been made from auroral to lower mid¬ 
latitude stations to study the behavior of the 
ionosphere during large magnetic storms. 
Contours of percentage variations of TEC 
during storms as compared to monthly 
average values have been prepared showing 
data over the invariant latitude range from 
38 to 67 degrees. Large afternoon enhance¬ 
ments are likely due to the electro-dynamic 
effects associated with the dawn-dusk mag- 
netospheric convection electric fields which 
produce a large upward drift of the plasma 
in the mid-latitudes to a region of lower loss. 
In the high latitudes the drifts are mostly 
horizontal, poleward and westward, caus- 


9C srio <i o to * icic «- nr c 

• • i ' 



S <1 4> ‘ A ' *«oA* *90 K 

•to "ii t? i * r* oi •'»'***• 


cm- i oi o»’ : so; •( 


« • • « •« 



00 5* ./ .• It 34 it 

■*»» 1 sm • 0 m. « c p« m 


A magnetic storm during the summer can 
cause depressions in the TEC which last much 
longer than those following magnetic storms 
during the winter. 


tng ionization to pile up in the afternoon 
sector. Large depletions in ionization at 
0400 local time at 53 degrees invariant lati¬ 
tude also occur due to the equatorward 
motion of the main trough region during 
magnetic storms. 

During the later phases of magnetic 
storms the enhanced auroral heating pro¬ 
duces greater molecular concentrations at 
F-region heights with consequent greater 
ionization loss rates. The resulting de¬ 
pressed TEC values can last several days 
after a msyor magnetic storm, especially 
during the local summer months, with a 
much shorter recovery time in the winter. 

Plasmasptwric Electron Content: The 
launch of the ATS-6 geostationary satellite 
with a special ionospheric beacon trans¬ 
mitter allowed the first capability of making 
group delay measurements simultaneously 
with Faraday rotation measurements of the 
ionosphere. Faraday rotation measures 
electron content out to approximately 2500 
kilometers height, while the group delay 
measures electron content out to the geo¬ 
stationary satellite height of 35,800 kilo¬ 
meters. The difference between these two 
quantities can be used to infer the electron 
content of the region above approximately 
2,500 kilometers, referred to as the plasma- 
spheric electron content. The major new 
finding from plasmaspheric electron content 
determinations is the large difference in the 
average diurnal behavior observed in the 
United States and the European longitude 
sectors. In the United States longitude 
sector, the diurnal minimum in plasma- 
spheric electron content occurs near midday 
except during the summer months, while in 
the European longitudes it has its diurnal 
maximum near midday. The difference in 
diurnal shape of the two values has been 
explained as being due to the greatly dif¬ 
ferent geographic latitudes of the magnetic 
conjugate regions for the two stations. The 
magnetic corrugate of the United States 
stations is in the Antarctic region while that 
for the European station is in the southern 
midlatitudes. 








88 


I 


< 

i 

i 

■< 

i 

t 

s 


Ionospheric Modification Studies: In a 

continuing study of the effects of enhanced 
Fl* region loss processes, AFGL partici¬ 
pated in Project LAGOPEDO, an effort to 
create a hole in the F-region by deposition of 
approximately 100 kg or 10-“ molecules of 
water vapor into the dusk sector ionosphere 
near Hawaii in September 1977. A rapid 
decrease in TEC was seen along a path 
passing within approximately 1 km of the 
chemical deposition. A ray path from 
another satellite which passes approxi¬ 
mately 80 km from the chemical deposition 
point showed no effects. Calculations show 
that the chemically enhanced loss process 
was perhaps only a few percent as efficient 
as the much larger ionospheric depletion 
observed due to the Skylab launch in 1973. 
The VHF amplitude from the geostationary 
satellite being observed l emained enhanced 
by from 2 to 5 dB for at least 36 minutes 
after the event due to ray focusing through 
the hole produced by the chemical deposi¬ 
tion. 

SOLAR RADIO RESEARCH 

The Solar Radio Astronomy Section of 
the Trans-Ionospheric Propagation Branch 
is engaged in making and analyzing radio 
observations of solar radiation in the 8 mm 
to 1.2 meter wavelength range, advising the 
Electronic Systems Division on the instal¬ 
lation and acceptance testing of the Radio 
Solar Telescope Network, and performing 
research on the nature of various solar phe¬ 
nomena and their impact upon the iono¬ 
sphere an J : magnetosphere of the earth. The 
observations are of two types: whole-sun 
observations where the antenna beam- 
widths are larger than the angular diameter 
of the sun (approximately 32 minutes of arc): 
and high resolution studies where the an¬ 
tenna beam widths are of the order of 1 arc- 
sec to 4 arc-min making it possible to ob¬ 
serve a single active region on the face of the 
sun. In some instances it is possible to scan 
the active region and develop a map. This 
procedure has also been used to study solar 
“coronal holes". The polarization of the 
radiation from active regions has been 


studied both while the region is in a qui¬ 
escent state and before, during and after the 
occurrence of a flare. 

High resolution studies of quiescent 
active regions at centimeter and millimeter 
wavelengths have shown the regions to 
exhibit small scale (approximately 10 sec¬ 
onds of arc) sources of circularly polarized 
(approximately 40 percent) emission. The 
size, intensity, and degree of polarization of 
these sources are very stable for intervals of 
time up to several days. This stability is 
disrupted, however, with a great en¬ 
hancement of the polarization of the emis¬ 
sion (up to 80 percent) from the region in the 
period up to one hour before the region 
produces a flare. This polarization en¬ 
hancement is an indication of magnetic field 
changes taking place in the region. With the 
increase in the solar activity cycle, the 
search for association of this pre-burst 
phenomenon with proton-producing flares is 
being pursued. 

The U-shaped radio burst has been 
investigated to discover if it is possible to 
predict the nature of the proton flux 
associated with it. A joint AFGL-Boston 
College effort has shown that the width of 
the interval between the frequency at which 
the energy peaks and the frequency at 
which the energy is a minimum is well 
correlated (approximately 78 percent) with 
the proton energy spectrum in the 10 to 100 
MeV range. If the ratio is large, the proton 
spectrum is hard; i.e., there are relatively 
more higher-energy particles. If the ratio is 
small, there are relatively fewer higher- 
energy protons. An influx of energetic 
protons with relatively more higher-energy 
particles has a greater impact upon the 
earth’s ionosphere, causing more severe 
disruption. The impact of a large number of 
high energy protons on satellites, manned 
and unmanned, is potentially devastating. 

Earlier work at AFGL had shown that 
the particle peak flux could be related to the 
integrated radio flux of a burst at one 
frequency. This effort has been expanded to 
provide an improved prediction scheme 





8S 


Ionospheric Modification Studies: In a 

continuing study of the effects of enhanced 
F 2 region loss processes, AFGL partici¬ 
pated in Project LAGOPEDO, an effort to 
create a hole in the F-region by deposition of 
approximately 100 kg or 10-* molecules of 
water vapor into the dusk sector ionosphere 
near Hawaii in September 1977. A rapid 
decrease in TEC was seen along a path 
passing within approximately 1 km of the 
chemical deposition. A ray path from 
another satellite which passes approxi¬ 
mately 80 km from the chemical deposition 
point showed no effects. Calculations show 
that the chemically enhanced loss process 
was perhaps only a few percent as efficient 
as the much larger ionospheric depiction 
observed due to the Skylab launch in 1973. 
The VHF amplitude from the geostationary 
satellite being observed remained enhanced 
by from 2 to 5 dB for at least 36 minutes 
after the event due to ray focusing through 
the hole produced by the chemical deposi¬ 
tion. 

SOLAR RADIO RESEARCH 

The Solar Radio Astronomy Section of 
the Trans-Ionospheric Propagation Branch 
is engaged in making and analyzing radio 
observations of solar radiation in the 8 mm 
to 1.2 meter wavelength range, advising the 
Electronic Systems Division on the instal¬ 
lation and acceptance testing of the Radio 
Solar Telescope Network, and performing 
research on the mature of various solar phe¬ 
nomena and their impact upon the iono¬ 
sphere and magnetosphere of the earth. The 
observations are of two types: whole-sun 
observations where the antenna beam- 
widths are larger than the angular diameter 
of the sun (approximately 32 minutes of arc); 
and high resolution studies where the an¬ 
tenna beamwidths are of the order of 1 arc- 
sec to 4 arc-min making it possible to ob¬ 
serve a single active region on the face of the 
sun. In some instances it is possible to scan 
the active region and develop a map. This 
procedure has also been used to study solar 
"coronal holes". The polarization of the 
radiation from active regions has been 


studied both while the region is in a qui¬ 
escent state and before, during and after the 
occurrence of a flare. 

High resolution studies of quiescent 
active regions at centimeter and millimeter 
wavelengths have shown the regions to 
exhibit small scale (approximately 10 sec¬ 
onds of arc) sources of circularly polarized 
(approximately 40 percent) emission. The 
size, intensity, and degree of polarization of 
these sources are very stable for intervals of 
time up to several days. This stability is 
disrupted, however, with a great en¬ 
hancement of the polarization of the emis¬ 
sion (up to 80 percent) from the region in the 
period up to one hour before the region 
produces a flare. This polarization en¬ 
hancement is an indication of magnetic field 
changes taking place in the region. With the 
increase in the solar activity cycle, the 
search for association of this pre-burst 
phenomenon with proton-producing flares is 
being pursued. 

The U-shaped radio burst has been 
investigated to discover if it is possible to 
predict the nature of the proton flux 
associated with it. A joint AFGL-Bo«to:i 
College effort has shown that the width of 
the interval between the frequency at which 
the energy peaks and the frequency at 
which the energy is a minimum is well 
correlated (approximately 78 percent) with 
the proton energy spectrum in the 10 to 100 
MeV range. If the ratio is large, the proton 
spectrim is hard; i.e., there are relatively 
more higher-energy particles. If the ratio is 
small, there are relatively fewer higher- 
energy protons. An influx of energetic 
protons with relatively more higher-energy 
particles has a greater impact upon the 
earth’s ionosphere, causing more severe 
disruption. The impact of a large number of 
high energy protons on satellites, manned 
and unmanned, is potentially devastating. 

Earlier work at AFGL had shown that 
the particle peak flux could be related to the 
integrated radio flux of a burst at one 
frequency. This effort has been expanded to 
provide an improved prediction scheme 




89 


using the integrated radio flux across a 
broad portion of the observed frequency 
spectrum. The radio emissions observed in a 
solar burst provide an indication of what is 
happening at the location of the flare. The 
energetic protons which reach the earth do 
so by traveling along the magnetic field lines 
which extend from the sun to the earth. The 
solar foot point of these field lines, at 
approximately 57 degrees W longitude on 
the face of the sun, may be some longitu¬ 
dinal distance away from the flare location. 
The particles which reach the earth must 
travel this distance across the face of the 
sun, and decrease in intensity due to col¬ 
lisions and other processes. When adjust¬ 
ment for the position of the flare relative to 
the magnetic field lines foot-point position 
was made, the proton peak flux prediction 
method showed an 8-10 percent improve¬ 
ment in the correlation coefficient of the 10 
MeV proton flux vs. integrated radio flux 
density. 

One advantage of solar radio observations 
is that they may be carried out even when 
the sun is obscured by clouds. If a proton 
flare should occur and its position on the face 
of the sun could not be optically determined 
because of adverse seeing, the effectiveness 
of the radio integrated flux density proton 
flux prediction process would be degraded. 
A method has been devised at AFGL, and is 
now being instrumented, which uses the 
radio data taken by a 25-75 MHz swept- 
frequency interferometer to indicate the 
solar position of the radio burst. The inter¬ 
ferometer also indicates the occurrence of 
Type II and Type IV bursts, which are 
associated with solar proton flares. The 
potential accuracy of this position deter¬ 
mination in the east-west direction is 1.5 
minutes of arc (referenced on the celestial 
sphere). 

A small-scale study of the polarization of 
the peak flux density emission of radio 
bursts in the 5.0 to 9.4 GHz range based on 
August 1972-December 1973 whole-sun 


observations has shown that about 80 per¬ 
cent of the bursts in that frequency interval 
were circularly polarized with varying 
degrees of polarization. Since the study 
made use of only 45 bursts, the resulting 
conclusions about burst polarization must 
be treated cautiously. When the polariza¬ 
tion increased toward the upper or lower 
end of the 5.0 to 9.4 GHz interval, the flux 
density of the burst increased in the same 
direction. If there was a reversal of the 
sense of circular polarization of the burst in 
the 5.0 to 9.4 GHz interval, the highest flux 
density of the burst usually occurred near 
the polarization reversal frequency. 

Another source of energetic solar par¬ 
ticles which impact the earth is the “coronal 
hole,” a region on the sun whose density and 
apparent temperature are lower than its 
surroundings. Coronal holes usually occur 
in the polar regions of the sun, although 
some have been observed to extend from 
one pole to another. The first coronal hole 
was found by observations made from the 
Skylab satellite in 1973. Since that time, 
earth-based attempts to observe them at 
various wavelengths in the electromagnetic 
spectrum have been successful. High-reso- 
lution radio maps have been made of coronal 
hole regions at various wavelengths. When 
these radio maps were superimposed on X- 
ray maps, the correspondence of the radio 
coronal holes with those of the X-ray and 
EUV photographs was apparent for the 
larger coronal holes, especially at decimeter 
wavelengths. It has been experimentally 
determined that the largest change in radio 
brightness temperature for coronal holes 
(relative to surrounding quiet regions) 
occurs in the decimeter wavelength range. 
In September 1977, a coronal hole was 
detected for the first time by radio observa¬ 
tions alone. From observations using the 
1000 ft Arecibo radiotelescope, maps were 
produced at 21 cm and 11.5 cm wavelengths 
showing as much as a 30 percent decrease in 
brightness temperature for the coronal hole 
region. 



90 


JOURNAL ARTICLES 
JULY 1976- DECEMBER 1978 

Aarons, J. 

Equatorial Scintillations 

Sp. Issue of Proe. of IEEE onSatel. Comm. 

(September 1977) 

Ionospheric Scintillation; An bit nut net ion 
Introduction to Radio Wore Propagation Effects on 
Systems 

AGARD Lect. Ser. 99, Recent Advances in Rad. and 
Opt. Prop, for Modem Comm., Navigation and 
Detection Sys. (May 1978) 

Aarons, J., Basu, S., and Martin, E. 

(EmmanuelColl., Boston, Mass.) 

The Stonntinie Component of Scintillations 
Geophys. UseofSatel. Beacon Observations, Proe. of 
Symp., Boston Univ. (1976) 

Aarons, J., Buchau, J., Basu, S. 

(Emmanuel Coll., Boston, Mass.), and McCLURE, 
J. P. (Univ. of Texas) 

The lAicalized Origin of Equatorial Irregularity 
Patches 

J. of Geophys. Res., Vol. 83, No. A4 (1 April 1978) 

Altrock, R. C. 

The Horizontal Variation of Temperature in the Low 
Solar Photosphere 
Solar Phys., Vol. 47 (1976) 

Intensity, Velocity and Temperature Fluctuations in 

the Upper Solar Photosphere 

Astron. and Astrophys., Vol. 57, No. 3 (May 1977) 

Altrock, R. C. and Keil, S. L. 

Intensity. Velocity and Temperature Fluctuations in 
the Upper Solar Photosphere 
Astron. and Astrophys., Vol. 57 (1977) 

Altrock, R. C. and Musman, S. 

Recurrent Geomagnetic Disturbances and Coronal 
Holes as Observed in Fe XTV 5.10.1 A 
J. ofGeophys. Res., Vol. 83(1978) 

Basu, S. 

OGO 6 Observations of Small-Scale I rregularity 
Structures Associated with Subtrough Density 
Gradients 

J. ofGeophys. Res., Vol. 83, No. A1 (1 January 1978) 
BASU, S. (Emmanuel Coll., Boston, Mass.), and 

Aarons, J. 

Daytime VHFScintillations at Huancayoand the 
Equatorial Electrojet 

The Geophys. UseofSatel. Beacon Observations, 
Symp. Proe. (1976) 

BASU, S. (Emmanuel Coll., Boston, Mass.), 
Aarons, J. and BALSLEY, B. B. (Natl. Oceanic 
and Atm. Adm., Boulder, Colo.) 

On the Nature of the Electrojet Irregularities 
Responsible for DaytineVHF Scintillations 
J. ofGeophys. Res., Vol. 83(November 1977) 


Basu, 3., Aarons, J., and Bushby, A., 

WOODMAN, R. W. (Inst. GeoftscioDel Peru, Lima, 
Peru), MC CLURE, J. P., and La HOZ, C. (Univ. 
of Texas at Dallas) 

Correlated Radar and Scintillation Studies in the 
Equatorial Region Simultaneous VHF Scintillation 
and.WMHz Radar Studies of F-Region Equatorial 
Irregularities 

J. of Atm. and Terres. Phys., Vol. 39, No. 9 
(September 1977) 

BASU, S. (Emmanuel Col)., Boston, Mass.)and 

Basu, S. 

In Situ Equatorial Irregularity Measurements and 
Scintillations at VHF and GHz 
Geophys. Res. Ltrs. (November 1976) 

Correlated Measurements of Scintillations and In- 
Situ F-Region Irregularities from OGO-6 
The Geophys. UseofSatel. Beacon Observations, 
Proe. of Symp., Boston Univ. (1976) 

BASU, S. (Emmanuel Coll., Boston, Mass.) BASU, 

S., Aarons, J., Me Clure, J. P. , and 

COUSINS, M. D. (Univ. of Texas at Dallas) 

On the Coexistence of KHometer-and Meter-Scale 
Irregularities in the Nighttime Equatorial F Region 
J. ofGeophys. Res., Vol. 83, No. A9(l September 
1978) 

Basu, S. and Basu, S., Khan, B. K. (Inst, of 

Rad. Phys. and Elect., Univ. of Calcutta, India) 

Model of Equatorial Scintillations from In-Situ 
Measurements 

Rad. Sci., Vol. 11, No. 10(1976) 

Basu, S., and Kelley, M. C. (Cornell univ., 
Ithaca, N. Y.) 

Review of Equatorial Scintillation Phenomena in 
Light of Recent Developments in the Theory and 
Measurement of Equatorial Irregularities 
J. of Atm. and Terres. Phys., Vol. 39, No. 9 
(September 1977) 

BINDER, 0. H. (Inst. furReineund Angewandte 
Kemphys., Univ. of Kiel, Kiel, Fed. Rep. ofGer.), 

Shea, M. A,, and Smart, D. F. 

Cosmic Ray Variational Coefficients — The Effect of 
Altitude Variations andSecu/arVariations 
15th Inti. Cosmic Ray Conf., Conf. Papers, Vol. 4 
(1977) 

Buchau, J., Weber, E. J., and Whitney, 
H. E, 

New Insight into Ionospheric Irregularities and 
Associated VHFIUHF Scintillations 
AGARDConf. Preprint No. 239, Dig. Comm. inAvion. 
(May 1978) 

Burke, W. J. (RegisColl. Weston, Mass.), 
Braun, H. J., Munch, J. W. (Max pianck inst. 
fur Aeron., Lindau, Gcr.), and SAGALYN, R, C. 
Observations from the INJUN 5 Satellite Concerning 
the Relative Positions of the Quiet Time Ring Current 
and the Topside Electron Temperature Maximum in 
the Trough 

Trans, of Am. Geophys. Union, Vol. 59(1978) 




91 


Burke, W. J., Donatelli, D. E. (Regis 

Coll., Weston, Mass,), and SAGALYN, R. C. 

Injun 5 Observations of Low-Energy Plasma in the 
High-Latitude Topside Ionosphere 
J. ofGeophys. Res., Vol. 83, No. A5(l May 1978) 

Canfi/xd, R. C. 

The Heigi t Variation of Granular and Oscillatory 
Velocities 

Solar Phys., Vol. 50(1976) 

Canfield, R. C., and Fisher, R. R. 

Magnetic Field Reconnection in the Flare of 18:29 UT 
1975 August 10 

The Astrophys. J., Vol. 210(15 December 1976) 

Canfield, R. C., and Stencl, R. E. 

Emission Lines in the Wings o/Ca II, Hand K. 

I. Initial Solar Observations and Implications 
The Astrophys. J., Vol. 209 (15 October 1976) 

Castelli, J. P. 

The Sagamore Hill Radio Observatory 

Bull, of Am. Astronom. Soc., Vol. 10, No. 1 (February 

1978) 

Castelli, J. P., and Barron, W. R. 

A Catalog of Solar Radio Bursts 1966-1976 Having 
Spectral Characteristics Predictive of Proton Activity 

J. of Geophys. Res., Vol. 82, No. 7 (19 May 1977) 

Castelli, J. P., Barron, W. R., and 
BADILLO, V. L. (Manila Obsv., Manila, 
Philippines) 

Highlights of Solar Radio Data, JO March -5 May 1976 
UAG Rpt. on Retrospective World Interval 20Mar. -5 
May 1976, No. 61 (1977) 

Castelli, J. P., and Guidice, D. A. 

Impact of Current Solar Radio Patrol Observations 
Vistas in Astron., Vol. 19 (1976) 

CHERNOSKY, E. J., and KLOBUCHAR, J. A. 
Diurnal Rates of Change in TEC Observed from Cape 
Kennedy - ATS-.l 

Min. of 13th Wkg. Gp. Mtg. of Jt. Satel. Stud. Gp (1976) 
COLEMAN, G. D. (StewardObsv., Univ. of Ariz.), 

and Worden, S. P. 

Large Scale Winds Driven by Flare Star Mass Loss 
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DANDEKAR, B. S., and PIKE, C. P. 

The Midday, Discrete Auroral Gap 

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Is the Sun a Short Period Variable ? 

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Dryer, M. (NOAA-ERL, Boulder, Colo.), and 
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Cooperation with the SCOSTEP 
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Solar Phys. Vol. 49(1976) 

Dryer, M. (NOAA-erl, Bouid. coio.). Shea, 
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On the Observation of a Flare-Generated Shock Wave 
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Dunn, R. B., and Mehltretter, J. P. 

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Solar Instrumentation 

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The Fine Structure of Prominences. I: Observations — 

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The Fine Structure of Prominences: Spectral 

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A Solution to the Problem of Spontaneous Line 
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Spontaneous Line Splitting in Maximum Entropy 
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Heavy Ion Circulation in the Earth's Magnetosphere 
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Spacecraft Charging at Geosynchronous Orbit- 
Generalized Solution for Eclipse Passage 
Geophys. Res., Ltrs., Vol. 5, No. 10(October 1978) 

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Worden, S. P. 

The Effects of Stellar Chromospheric Activity on 

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Hardy, D. A., Freeman, J. W., and Hills, 

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Double-Peaked Ion Spectra in the Lobe Plasma: 
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Hubbard, E., Strittmai ter, P., Woolf, 
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Speckle Interferometry at Steward Observatory 
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JASPERSE,J. R. 

Electron Distribution Function and Ion 
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Boltzma n n-Fokker-Pla nek Theory 
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J ASPERSE, J. R., and Smith, E. R. (Boston 
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The Photoelectron Flux in the Earth’s Ionosphere at 
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Geophys. Res. Ltrs., Vol. 5, No. 10 (October 1978) 

JOHANSEN, J. M. (EmmanuelColl., Boston, 
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The Variability of Ionospheric Time Delay 
Proc. of Symp. on Eff. of Iono. on Space and Terres. 
Sys., Arlington, Va. (January 1978) 

Keil, S. L. 

The Height Dependence of SolarVelocity Fluctuations 
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Keil, S. L., and CANFIELD, R. C. 

The Height Variation of Velocity and Temperature 
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Astron. and Astrophys., Vol. 70(1978) 

Kersley, L., Hajeb-Hosseinieh, H ., and 
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ATS-6 Observations of lonosphericIProtonospheric 
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Kersley, L., and Klobuchar, J. A. 

Comparison of Protonospheric Electron Content 
Measurements from the American and European 
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Geophys. Res. Ltrs., Vol. 5, No. 2(February 1978) 

Klobuchar, J. A. 

A Review of Ionospheric Time Delay Limitations to 
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The Geophys. UseofSatel. Beacon Observations, 
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Klobuchar J. A., Buonsanto, M. J.. 

MENDILl 0, M. J. (Boston Univ.), and 
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The Contribution of the Plasmasphere to Total Time 
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Proc. of Eff. of Iono. on Space and Tern .. Sys. Symp., 
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Klobuchar, J. A., Deshpande, M. R., 
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Effect of Electrojet on the Total Electron Content of the 
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Nature, Vol. 267 (16 June 1977) 

Klobuchar, J. A., Iyer, K.N. (Kerala Univ., 
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A Nu merical Model of Equatorial and Low Latitude 
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Ind. J. of Rad. and Space Phys. (June 1977) 

Konig, P. J Van Der Walt, A. J., 
Stoker, P. fl., Raubenheimer, B. C. 

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Afr.), Shea, M. A., and Smart, D. F. 

Vertical Cutoff Rigidity and the Intensity Distribution 

of Cosmic Rays NearCape Town 

15th Inti. Cosmic Ray Conf., Conf. Papers, Vol. 4 

(1977) 

Koutchmy, S. 

Study of the June do, 197d Trans-Polar Coronal Hole 
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Koutchmy, S., and Stellmacher, G. iinst. 

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Photospheric Faculae. II. Line Profiles and Magnetic 
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Photometric Study of Chromospheric and Coronal 
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LAI, S. T. (Logicon, Inc., Lexington, Mass.) 
SMIDDY, M., and WlLDMAN, P. J. L. 

Satellite Sensing of Low Energy Plasma Bulk Motion 
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Lovell, R. R., Stevens, J. (NASALewis 
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Spacecraft Charging Investigation: A Joint Research 
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MARTIN, E. (Emmanuel Coll., Boston, Mass.)and 

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Me NULTY, P. J., Farrell, G. E. (Clarkson 
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Threshold Pion Production and Multiplicity in 
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Phys. Rev. Ltr , Vol. (Spring 1977) 

Me NULTV, P. J., and FlLZ, R. C. 

Width Measurements on Neon and Nitrogen Tracks in 

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MC NULTY, P. J. (Clarkson Coll. ofTeehnol., 
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Hole pi Nuclear Stars in the Light Flashes Observed on 
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MC NULTY, P. J. (Clarkson Coll. ofTeehnol., 
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Particle Induced Visual Phenomena in Space 
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MENDILLO, M., Bl'ONSANTO, M. J. (Boston 
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Distortions of the Winter Nighttime Ionosphere atL- 

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Mullen, J. P., and Aarons, J. 

Scintillations Observed through the Magnetospheric 
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The Geophys. UseofSatel. Beacon Observations, 
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Mullen, E. G., Silverman, S. M., and 
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(Regis Coll. Res. Ctr., Weston, Mass.) 

5.57.7 nm (01) Night Airglow in the Central PolarCap 
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Mullen, J. P., Whitney, H. E., Basu, S. 

(EmmanuelColl., Boston, Mass.), BUSHBY, A,, 
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Statistics of VHFand L-BandScintillation at 
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MUSMAN, S., and ALTROCK, R. C. 

Recurrent Geomagnetic Disturbances and Coronal 
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J. of Geophys. Res., Vol. 83, No. A10(l October 1978) 


MUSMAN, S., and NELSON, G. D. 

The Energy Balance of Granulation 
The Astrophys. J., Vol. 207 (1 August 1976) 

Neidig D. F., Jr. 

Microwave Burst Spectra and Solar Flare Magnetic 
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Solar Phys., V >1.54, No. 1 (September 1977) 

Ha, Hard X-Ray, and Microwave Emissions in the 
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Solar Phys., Vol. 57 (April 1978) 

Pike, C. P., and Bunn, M. H. (Space and 
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A Correlation Study Relating Spacecraft Anomalies to 
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AIAA Prog. Ser. in Astro, and Aero., Ed. by A. 
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Pike, C. P., and Lovell, R. R. <nasa Lewis 
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Pike, C. P., Whalen, J. A., and Buchau, 

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A td-HourCase Study of Aurora! Phenomena in the 
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RADOSKI, H. R., ZAWALICK, E. J., and 
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The Superiority of Maximum Entropy Power 
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Phys. of Earth & Planet. Interiors, Vol. 12 (1976) 

Rao, L. D. V., Burke, W. J., Kanal, M. 

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Injun 5 Low-Energy Plasma Observations [hiring a 
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Rhodes, E. J., Jr., Ulrich, R. K. (Univ.of 
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Observations of Nonradial p-Mode Oscillations on the 
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ROTHWELL, P. L., FlLZ, R. C., and 
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Light Flashes Observed on Skylab i - The Role of 
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Sci., Vol. 193 (September 1976) 

Rothwell, P. L., Rubin, A. G., Pavel, 
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Simulation of the Plasma Sheath Surrounding a 
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Proc. of Conf. on Spacecraft Charging by Magneto. 
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94 


Rubin. A. G., Filz, R. C., Rothwell, P. 

L., and SELLERS, B. (Panamet., Inc., Waltham, 
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Geomagnetically Trapped Alpha Particles from 18-70 
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RUCINSKI, S. M. (Domin. Astrophys. Obsv., 
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Spectroscopic Orbit of CC Comae 
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Rush, C. M., and Edwards, W. R., Jr. 

An Automated Mapping Technique for Representing 
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Rad. Sci., Vol. 11, No. 11 (November 1976) 

SAGALYN, R. C., and BURKE, W. J. (Regis 
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Injun 5 Observations of Vehicle Potential 
Fluctuations at >500 Km 

Proc. of Spacecraft Charging Technol. Conf., Colo. 
Springs, Colo. (24 February 1977) 

Sagalyn, R. C., Burke, W. J., and 

DONATELLI, D. E. (Regis Coll., Weston, Mass.) 
Injun 5 Observations of Low-Energy Plasma in the 
High-Latitude Topside Ionosphere 
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Sagalyn, R. C., Wildman P. J. L., 
Munch, J. W Braun, H. J., and 

PlLKINGTON, G. R. (Max-Planck Inst, fur Aeron., 
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Thermal Electron Densities and Temperatures in the 
Da yside C asp Region 

J. of Atm. andTerres. Phys., Vol. 39 (June 1977); Proc. 
of Sec. Magneto. Cleft Symp., St. Jouite, Quebec, Can. 
(June 1977) 

SCHNEEBERGER, T. J. (N. M. State Univ.), 
LlNSKY, J. L. (JILA, Univ. of Colo.), and 

Worden, S. P. 

The HeI Triplet to Singlet Ratio in T-Tauri Stars 
Astron. and Astrophys., Vol. 62, No. 3 (January 1978) 

Sellers, B., Hanser, F. A., Morel, P. 

R., HUNERWADEL, J. L. (Panamet., Inc., 
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Rothwell, P. L. 

Design and Calibration of a High Time Resolution 
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Plasma - AIAA (October 1976) 

Sellers, B., Hanser, F. A, (Panamet., inc„ 
Waltham, Mass.), STROSCIO, M. A. (Los Alamos 
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The Night and Day Relationships Between PolarCap 
Riometer Absorption and Solar Protons 
Rad. Sci., Vol. 12, No. 5(October 1977) 


Shea, M. A. 

Solar Terrestrial Physics Data Exchange 
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Phys. Branch, Energy, Mines and Resources Can., 
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Overview of Solar-Terrestrial Physics Phenomena for 
the Retrospective World Interval of JO March - 5 May 
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Collected Data Rpts. for STIP Interval II, 20 Mar. - 5 
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Shea, M. A., and Lincoln, J. V. inoaa, 

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Overview of the International Effort in Solar- 
Terrestrial Physics Data Exchange with Emphasis on 
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Revista Geofisica, No. 6 (June 1977) 


Shea, M. A., and Smart, D. F. 

The Effects of Recent Secular Vanations of the 
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15th Inti. Cosmic Ray Conf., Conf. Papers, Vol. 4 
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Significant Solar Proton Events, 1985-1969 
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Shea, M. A., Smart, D. F., and Coffey, H. 

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A Summary of Sign ificant Solar-Terrestrial and 

lnterpla netary Events Du ri ng the Retrospective World 

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15th Int’l. Cosmic Ray Conf., Conf. Papers, Vol. 5 

(1977) 

A Summary of Significant Solar-Initiated Events 
During STIP Intervals I and II 
Study of Travelling Interplan. Phenom./1977, Ed. by 
M. A. Shea, D. F. Smart and S. T. Wu, D. Reidel Pub. 
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Shea, M. A., Smart, D. F., andPALMEiRA, 
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Vertical Cutoff Rigidities Over South America for 
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Revista Geofisica, No. 6 (June 1977) 

Smart, D. F. 

SILAFand Special Proton Events 
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Phys. Branch, Energy, Mines and Resources Can., 
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95 


Smart, D. F., and Shea, M. A. 

Application of Elementary Coronal Propagation and 
Co-Rotational Concepts to Solar Proton Event 
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15th lntl. Cosn.ic Ray Conf., Conf. Papers, Vol. 6 
(1977) 

Prediction of the Solar Proton Time-Intensity Profiles 
for the .10 April 1976 Event 
Space Res. XVIII (1978) 

Smart. D. F., Shea, M. A., Dodson, H. 

W., and HEDMAN, E. R. (McMath-HulbertObsv., 
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Distribution of Proton Producing Flares Around the 
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Space Res. XVI, Ed. by M. J. Rycroft (1976) 

Smiddy, M., Sagalyn, R. C., Burke, W. 

J. (Regis Coll., Weston, Mass.), LAI, S. T. 

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Electric Fields at High Latitudes in the Topside 
Ionosphere Near the Daum-Dusk Meridian 
Space Res. XIX (1978) 

Smiddy, M., Sagalyn, R. C., Shuman, B., 
Kelley, M. C. (Sch. of Elec. Engre., Cornell 
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Intense Poleward-Directed Electric Fields Near the 
Ionospheric Projection of the Plasmapause 
Geophys. Res. Ltrr , Vol. 4, No. 11 (November 1977) 

Smiddy, M., Wildman, P. J. L., and Lai, S. 

T. (Logicon, Inc., San Pedro, Calif.) 

Satellite Sensing oj Low Energy Plasma Bulk Motion 
Proc. of Conf. on Aerosp. and Aero. Met. and Symp. on 
Remote Sensing from Sate!. (November 1976) 

Straka, R. M. 

Sagamore Hill Radio Observatory 

Bull, of Am. Astronom. Soc., Vol. 9, No. 1 (February 

1977) 

Wagner, W. J. 

Coronal Holes Observed by OSO-7and Interplanetary 

Magnetic Sector Structure 

The Astrophys. J., Vol. 206(1976) 

Rotational Characteristics of Coronal Holes 
Basic Mechanisms of Solar Activity (1976) 

Wagner, W. J., and Gilliam, L. B. 

A Possible Example of Giant Convective Cells 
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Solar Phys., Vol. 50(1976) 

Weber, E. J., Buchau, J., and Eather, R. 
H., MENDE, S. B. (Boston Coll., Chestnut Hill, 
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North/South Aligned Equatorial Airglow Depletion* 

J. of Geophys. Res., Vol. 83, No. A2(February 1978) 


WEBER, E. J., MENDE.S. B. (LockheedPalo 
Alto Res. Labs., Calif.), and EaTHER, R. H. 
(Boston Coll., Chestnut Hill, Mass.) 

Optical Diagnostics of the August 1972 PC A Event 
J. of Geophys. Res., Vol. 81, No. 31 (November 1976) 

Weber, E. J., Whalen, J. A., Wagner, 
R. A., and Buchau, J. 

A 12-HourCase Study of Auroral Phenomena in 
Midnight Sector: Electrojet and Precipitating Particle 
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J. of Geophys. Res., Vol. 82, No. 25 (1 September 1977) 
Coordinated Airborne, Ground Based and Satellite 
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J. of Geophys. Res., Vol. 82, No. 25 (1 September 1977) 

WELTER, G. L., (WashburnObsv., Univ. of Wise., 
Madison, Wise.) and WORDEN, S. P. 

A Method for Processing Stellar Speckle 
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J. of Opt. Soc. of Am., Vol. 68, No. 9 (September 1978) 

Whalen, J. A., Wagner, R. A., and 
Buchau, J. 

A 12-Hour Case Study of Aurora! Phenomena in the 
Midnight Sector: Oval, Polar Cap, and Continuous 
Auroras 

J. of Geophys. Res., Vol. 82, No. 25 (1 September 1977) 

Whitney, H. E. 

Amplitude and Rate Characteristics of Intense 
Scintillations 

Proc. of Symp. of COSPAR Satel. Beacon Gp. on The 
Geophys. UseofSatel. Beacon Observations (1 August 
1976) 

Amplitude and Rate Characteristics of Intense 
Scintillations 

Rad. Sci., Vol. 12, No. 1 (January-February 1977) 

WHITNEY, H. E., and BASU, S. (Emmanuel 
Coll., Boston, Mass.) 

Effect of Ionospheric Scintillations on VHF-UHF 

Satellite Communications 

Rad. Sci., Vol. 12, No. 1 (January-February 1977) 

Wildman, P. J. L. 

A Low Energy Ion Sensorfor Space Measurement* 
with Reduced Photo-Sensitivity 
Space Sci. Instmn., Vol. 3, No. 4 (1977) 

Wildman. P. J. L., Sagalyn, R. C.,and 

AHMED, M. (RegisColl., Weston, Mass.) 

Structure and Morphology of the Main Plasma Trough 
in the Topside Ionosphere 
Proc. of COSPAR Satel. Beacon Gp. Symp., Boston, 
Mass. (September 1976) 

WlLKERSON, M. S. (Steward Obsv., Univ. of 
Ariz.), and WORDEN, S. P. 

Further Speckle Interferometric Studies of Alpha 
Orionis 

Astronom. J., Vol. 82, No. 8(August 1977) 



96 


Worden, S. P. 

Looking at the Surfaces ofOthei Stars 

Res. Frontier, The Phys, Teacher, Vol. 14 (November 

1976) 

Astronomical Image Reconstruction 
Vistas in Astron,, Vol. 20(1977) 

Speckle Interferometry 
New Sci., Vol. 78 (27 April 1978) 

How Astronomers Take the Twinkle Away from Little 
Stars 

New Sci., Vol. 78(1978) 

Worden, S. P., and Coleman, G. D. 

(Steward Obsv., Univ. ofAriz.) 

Large Scale Winds Driven by Flare Star Mass Loss 
The Astrophys. J., Vol. 218 (1977) 

Worden, S. P., Coleman, G. D. (Steward 

Obsv., Univ. ofAriz.), RUCINSKI, S. M. (Dominion 
Astrophys. Obsv., Victoria, B. C., Can.), and 
WHELAN, J. A. I. (Anglo-Aust. Obsv., Epping, N. 
S. V'. Aust.) 

A Study of the Contact Binary System ER Cephei 
Mo. Notices of the Royal Astronom. Soc., Vol. 184 
(1978) 


Worden, S. P., Giampapa, M. S. (Univ. of 
Ariz.), LlNSKY, J. L. (Univ. of Colo.), and 
SCHNEEBERGER, T. J. 

Chromospheric Emission Lines in the Red Spectrum 
of AD Leonis. I. The Nonflare Spectrum 
the Astrophys. J., Vol. 226 (1978) 

Worden, S. P., and Lynds, C. R., 
Harvey, J. W. (Kitt Peak Natl. Obsv., Tucson, 
Ariz.) 

Reconstructed Images of Alpha Ononis Using Stellar 

Speckle Interferometry 

J. of Opt. Soc. of Am., Vol. 66(1976) 

Worden, S. P., and Peterson, B. M. 

(StewardObsv., Univ. ofAriz.) 

The Emission Lines in the Vicinity of Hydrogen-Alpha 

i n dMe Flare Star Spectra 

The Astrophys. J., Vol. 206 (1976) 

Worden, S. P., and Simon, G. W. 

Velocities Observed in Supergranules 
Basic Mechanism of Solar Activity (1976) 

On the Origin of 2* 40'" Solar Oscillations 
Ltr. to Ed., Astrophys. J., Vol. 210, No. 3(15 
December 1976) 

A Study of Supergranulation Using a Diode Array 

Magnetograph 

Solar Phys., Vol. 46(1976) 

Worden, S. P., and Wilkerson, M. S. (Kitt 

Peak Natl. Obsv , fucson, Ariz.) 

On Egregious Theories — The Tunguska Event 
Qtr. J of Royal Astronom. Soc., Vol. 19 (1978) 


Worden, S. P., Stein, M. K., Schmidt, G. 
D., and ANGEL, J. R. P. (StewardObsv., Univ. of 
Ariz.) 

The Angular Diameter of Vesta from Speckle 
Interferometry 

ICARUS, Vol. 32, No. 4 (December 1977) 

Zawalick, E. J., Radoski, H. R. , and 
Fougere, P. F. 

Spontaneous Line Splitting in Maximum Entropy 

Power Spectrum Analysis 

Phys, of Earth and Planet. Interiors, Vol. 12 (1976) 


PAPERS PRESENTED AT MEETINGS 
JULY 1976-DECEMBER 1978 

Aarons, J. 

Radio Wave Propagation Research in Support ofC :l 
Systems 

Mil. Ops. Res. Soc., Naval Postgrad. Sch., Monterey, 
Calif. (13-15 December 1977) 

Forecasting and Prediction of High and Equatorial 
Latitude Scintillation 

AGARD/NATOSymp. on Op. Modeling of the Aerosp. 
Prop. Envmt., Lisbon, Portugal (17-21 April 1978) 
Ionospheric Scintillation: An Introduction 
NATO/AGARD EPPSymp. on Op. Modeling of 
Aerosp. Prop. Envmt., Ottawa, Ont., Can. (17-21 
April 1978); AGARD Lecture Ser. 93, Oslo, Norway 
(8-9 May 1978); London, Eng. (11-12 May 1978); Rome, 
Italy (15-16 May 1978) 

Equatorial and High Latitude Empirical Models of 
Scintillation Levels 

Op. Modeling of the Aerosp. Prop. Envmt., The Natl. 
Conf. Ctr., Ottawa, Can. (24-28 April 1978) 
Introduction to Radio Ware Propagation Effects on 
Systems 

AGARD Lecture Ser. 93, Oslo, Norway (8-9 May 
1978); London, U. K. (11-12 May 1978); Rome, Italy 
(15-16 May 1978) 

A Renew of Recent Amplitude Scintillation 
Observations 

Inti, Union of Rad. Sci. (URSI), Helsinki, Finland (31 
July -10 August 1978) 

Aarons, J., Buchau, J., and Basu, S. 

(Emmanuel Coll., Boston, Mass.), Me CLURE, J. 
P. (Univ. of Texas at Dallas) 

The Localized Origin of Equatorial Irregularity 
Patches 

USNC/URSI Mtg., Stanford Univ., Stanford, Calif. 
(20-24 June 1977) 

Aarons, J., and Klobuchar, J. A. 

Ionospheric Scintillations and Total Electron Content 
Studies and Their Relevance to Communication and 
Radar Systems 

Natl. Telecomm. Conf., Birmingham, Ala. (4-6 
December 1978) 



97 


AARONS, J., and Martin, E. (Emmanuel Colli, 
Boston, Mass.) 

A High iMtitude Empirical Model of Scintillation 
Excursions: Phase I 

USNC/URSI Mtg., Stanford, Calif. (20-24 June 1977) 

Aarons, J., Whitney, H ., and 

Mac Kenzie, E. M. (EmmanuelColl., Boston, 

Mass.) 

The Formation, Duration, and Decay of Equatorial 
Irregularity Patches: The Ground Scintillation 
Observations 

Comsn. G, Natl. Rad. Sei. Mtg. of URSI, Boulder, 
Colo. (5-10 November 1978) 

AHMED, M. (RegisColl., Weston, Mass.), and 

Sagalyn, R. C. 

Topside Ionospheric Trough Morphology at Mid- and 
High-Latitudes 

Iono. Eff. Symp., Arlington, Va. (24-26 January 1978) 
AHMED, M. (Regis Coll., Weston, Mass.), 

Sagalyn, R. C., and Wildman, P. J. L. 

Morphology: Occurrence Frequency, Diurval, 
Seasonal, and Altitude Variations 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 


BASU, S. (Emmanuel Coll., Boston, Mass.), 
Aarons, J., Me CLURE, J. P. (Univ. of Texas 
at Dallas), and CALERON, C. (Rad. Observatoriode 
Jieamarea, Lima, Peru) 

Combined Study of Nighttime Equatorial 
Irregularities by Radar Backscatter, Ground-Based 
and Airborne Scintillation Measurements 
Am. Geophys. Union 1977 Spring Mtg., Wash. D. C. 
(30 May-3 June 1977) 

BASU, S. (Emmanuel Coll., Boston, Mass.), BASU, 
S., Aarons, J., McClure. J. P. (Univ.of 
Texas at Dallas), and COUSINS, M. D. (Stanford 
Res. Inst., Menlo Pk., Calif.) 

On the Co-Existence of Km- and M-Sized 
Irregularities in the Nighttime Equatorial Ionosphere 
USNC/URSI Mtg., Boulder, Colo. (9-13January 1978) 


BASU, S. , BASU, S. (EmmanuelColl., Boston, 

Mass.), Aarons, J ., Buchau, J. , Me Clure, 

J. P. (Univ. of Texas at Dallas), and COUSINS, M. 
D. (SRI Inti., Menlo Pk., Calif.) 


Equatorial Irregularity Campaigns: Large and Small 
Scale Properties of Nighttime F-Region Irregularities 
Inti. Union of Rad. Sei. (URSI)Gen. Asbly., Helsinki, 
Finland (31 July -10 August 1978) 


Allen, R. S., Du Long, D. D. (Regis Coil., 
Weston, Mass.), GROSSI, M. D., and ,KaTZ, A. 
H. (Raytheon Co., Wayland, Mass.) 

Experimental Evaluation of Adaptive Ionospheric 
Range Error Correction in High Accuracy Radar 
IEEE/URSI Mtg., Stanford Univ., Stanford, Calif. 
(20-24 June 1977) 


Allen, R. S., Du Long, . D. D. (Regis coil., 

Weston, Mass.), HARTMANN, G. K. (Institutfur 
Aeron., Lindau/Hartz, Fed. Rep. ofGer.), and 
LEITINGER, R. (Univ. ofGraz., Aus.) 

Adaptive Modeling of Ionospheric Effects Over the 
Field of View of Radar and Na ligation Systems Using 
TRANSIT Satellite Measurements 
IEEE/URSI Mtg., Stanford, Univ., Stanford, Calif. 
(20-24 June 1977) 


BASU, S. BASU, S. (EmmanuelColl., Boston, 
Mass.), RlNO, C. L. (SRI Inti., Menlo Pk. Calif.), 
Me Clure, J. P., and Hanson, W. B. (Univ. 

of Texas at Dallas) 

Spectral and Geometrical Characteristics ofF-Region 
Equatorial I rregularities from CoordinotedGHz 
Scintillation and In-Situ Measurements 
Inti. Union of Rad. Sci. (URSI) Gen. Asbly., Helsinki, 
Finland (31 July -10 August 1978) 

BASU, S. and KELLEY, M. C. (Cornell Univ., 
Ithaca, N. Y.) 

A Reinew of Recent Studies of Equatorial F-Region 
Irregularities and Their Impact on Scintillation 
Modeling 

The Eff. of Iono. on Space and Terres. Sys. Symp., 
Naval Res. Lab., Arlington, Va. (24-26 January 1978) 


Allen, R. S., Katz, A. H., Gkossi, N. D. 

(RaytheonCo., Wayland, Mass.), and DONATELLI, 
D. E. (RegisColl., Weston, Mass.) 

Adaptive Correction of the Effect of the Ionosphere on 
Range Determination by Terrestrial Radars 
Symp. on Eff. of Iono. on Space and Terres. Sys., 
Naval Res. Lab., Arlington, Va. (24-26 January 1978) 

AlTROCK, R. C., and MUSMAN, S. A. 

The Sacramento Peak Observatory Green-Line 
Coronal Patrol 

Mtg. on Solar and Interplanet. Phys., Tucson, Ariz. 
(12-15 January 1977) 

Coronal Holes as Observed in Fe XIV 540.1 A 
150th Mtg. of Am. Astronom. Soc., Atlanta, Ga. (12-15 
June 1977) 


BASU, S. (Emmanuel Coll., Boston, Mass.), 

Whitney, H., Aarons, J., and Me Clure, 

J. P. (Univ. of Texas at Dallas) 

Large and Small Scale Properties of Nighttime 
Equatorial I rregularities from Scintillations and 
Radar Backscatter Measurements 
Symp. of Eff. of Iono. on Space and Terres. Sys., Naval 
Res. Lab., Arlington, Va. (24-26 January 1978) 

BINDER, O. H. (Inst, fur Reine und Angewandte 
Kemphysik, Univ. of Kiel, Kiel, Fed. Rep. ofGer.), 

Shea, M. A., and Smart, D. F. 

Cosmic Ray Variational Coefficients — The Effect of 
Altitude Variations and Secular Variations 
15th Int). Cosmic Ray Conf., Plovdiv, Bulgaria(13-26 
August 1977) 





98 


BOYLE, R. P. (Emmanuel Coll,, Boston, Mass.), 
Smart, D. F., and Shea, M, A. 

Polar Cap Solar Proton Pitch Angle Distributions 
Observed by the S.l-J Satellite During March-Apri! 
1076 

1978 Fall Mtg. of Am. Geophys. Union San Francisco, 
Calif. (4-8 December 1978) 


Buchau,J., Aarons, J., Mullen, J. P., 
Weber, E. J., Whalen, J. A., Whitney, 
H. E., andCRAMPTON, E. E., JR. 

Amplitude Scintillation Studies in the Polar Region 
on JSO MHz 

1978 Symp. on Eff. of Iono. on Space aH Terres. Sys., 
Arlington, Va. (24-26 January 1978) 


BUCHAU, J., BiBL, K., and REINISCH, B.W. 
(Univ. of Lowell, Lowell, Mass.) 

Doppler Technique Vsed in Airborne Ionospheric 
Sounding of High-Latitude Ionosphere 
1978 Inti. IEEE/AP-S Symp.-USNC/URSI Mtg., 
Univ. of Md„ Coll. Pk„ Md. (15-19 May 1978) 


BURKE, .W J. (RegisColl., Weston, Mass.), 
Braun, H. J., Munch, j. W. (Max Planck inst. 
fur Aeron., Lindau, Ger.), and SAGALYN, R. C. 
Observations from the INJUN S Satellite Concerning 
the Relative Positions of the Quiet Time Ring Current 
a nd the Topside Electron Temperature Maximum in 
the Trough 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 


Castelli, J. P. 

A New Sola r Radio Netuork 

150th Mtg. of Am. Astronom. Soe., Atlanta, Ga(12-15 

June 1977) 


Castelli, J. P., and Tarnstrom, G. L. 

Solar Radio Burst Energies for March-Aprii 1976 
Events 

Comm, of Space Res. Symp. on Study of Traveling 
Interplanet. Phenom., Tel Aviv, Israel (7-18 June 
1977) 


Buchau, J., Hall, W. N., and Reinisch, 
B. W., Smith, S. (Univ. of Lowell, Ctr. for Atm. 
Res., Lowell, Mass.) 

Remote Ionospheric Monitoring 

Symp. on the Eff. of Iono. on Space Sysm. and Comm ., 

Arlington, Va. (24-26 January 1978) 


Buchau, J., Weber, E. J., and McClure, 

J. B. (Univ. ofTexas at Dallas) 

Radio and Optical Diagnostics Applied loan Isolated 
Equatorial Scintillation Event 
Symp. on Eff. of Iono. on Space Sys. and Comm., 
Arlington, Va. (24-26January 1978) 


Buchau, J., Weber, E. J,, and Whitney, 
H. E. 


New Insight into Ionospheric Irregula cities a nd 
Associated VHFIUHF Scintillations 
AGARD Mtg., Baden-Baden, Ger. (5-9 June 1978) 


BUCKNAM, D. B. (World Data Ctr. A for Solar 
Terres. Phys., Boulder, Colo.), and SHEA, M. A. 
Event Oriented Data Collection for the Ground-Level 
Solar Cosmic Ray Event of .10 April 1976 
15th Inti. Cosmic Ray Conf., Plovdiv, Bulgaria (13-26 
August 1977) 


BUONSANTO, M. J. (Rad. Res. Ctr., The Univ. of 
Auckland, Auckland, N. Z.), and MENDILLO, M. 
(Boston Univ., Boston, Mass.) 

A Model Simulation Study of Satellite Beacon Derived 
Observations of Plasmaspheric Content 
Enhancements Associated with Geomagnetic Storms 
Comm, on Space Res. (COSPAR) Mtg., Florence, Italy 
(22-25 May 1978) 


Dandekar, B. S. 

Gap in Midday Discrete Auroral Arcs 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 

Fla. (17-21 April 1978) 


Dandekar, B. S., and Pike, C. P. 

Dayside Auroral Gap 

Geophys. Union 1977 Spring Mtg., Wash., D. C. (30 
May-3 June 1977) 


DE MASTUS, H. L., and WAGNER, W. J. 

(High Alt. Obsv., NCAR, Boulder, Colo.) 

The Compatibility ofSPO Green Line and ATM White 
Light Transient Observations 
150th Mtg. of Am. Astronom. Soc., Atlanta, Ga (12-15 
June 1977) 


DONATELLI, D. D. (RegisColl., Weston, Mass.), 
and Allen, R. S. 

Temporal Variability of Ionospheric Refraction 
Correction 

Eff. of Iono. on Space and Terres. Sys., Naval Res. 
Lab., Arlington, Va. (24-26January 1978) 


Dryer, M, (Noaa-erl, Boulder, Colo.). Shea, 
M. A., Smart. D. F., andC ollard, H. R., 
Mihalov, J. d., Wolfe, J. H. (NASA Ames 
Res. Ctr., Moffett Fid., Calif)., and WARWICK, J. 
(Univ. of Colo.) 

On the Observation of a Flare-Generated Shock Waie 
at 9.7 AU by Pioneer 10 

1978 Spring Mtg. of Am. Geophys. Union, Miami 
Beach, Fla. (17-21 April 1978) 


99 


< 


1 

8 


< 


1 

A 



Dubs, C. W. 

On Cremona and Stonner Mapping for Particle 
Lifetimes 

Am. Geophys. Union Fall Mtg., San Francisco, Calif. 
(5-9 December 1977) 

Delineation of Long Lifetime Particles Trapped in a 
Dipole Magnetic Field 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Solubility of the BonndStonner Problem and Particle 
Lifetimes 

Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 
CIO May-:) June 1977) 


Fougere, P. F. 

The AFGL Magnetometer Network : A Progress Report 
Inti. Assoc, of Geomag. and Aeron./IAMAPMtg., 
Seattle, Wash. (22 August -3 September 1977) 

Sunspots: PowerSpecrtra and a Forecast 

Am. Geophys. Union Fall Mtg., San Francisco, Calif. 

(4-8 December 1978) 

Maximum Entropy Power Spectral Analysis 
Inti. Assoc, of Geomag. and Aeron./IAMAP, Seattle, 
Wash. (22 August - 3 September 1977) 

Obsecrations of Hydromagnetic Wares Using the 
AFGL Magnetometer Network 
Am. Geophys. Union Fall Mtg., San Francisco, Calif. 
(5-9 December 1977) 

A Solution to the Problem of Spontaneous Line 
Splitting in Maximum Entropy Power Spectrum 
Analysis of Complex Signals 
Spectrum Estimation Wkshp., Hq. RADC, Griffiss 
AFB, N. Y. (24-26 May 1978) 

Fougere, P. F., and Knecht, D. J. 


High-Time-Resolution Study of Sudden 
Com mencements Using AFGL Magnetometer Data 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 


Freeman, J. W., Hills, H. K., Hill, T. 

W., REIFF, P. H. (Rice Univ,, Houston,Tex.), and 

Hardy, D. A. 


Heaiy Ions in the Magnetosphere 

Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 

(30 May-3 June 1977) 

Circulation Mechanisms Responsible forO' Ions in 
Remote Parts of the Magnetosphere 
Inti. Assoc, of Geomag. and Aeron. Mtg., Seattle, 
Wash. (22 August - 3 September 1977) 


Garrett, H. B. 

Joint AFINASA Efforts in Modeling the 
Geosynchronous Environment 
Inti. Assoc, of Geomag. and Aeron. Mtg., Seattle, 
Wash, (22 August - 3 September 1977) 

Modeling of the Geosynch ronous Orbit Plasma 
Environment, Part i 

1978 Spring Mtg. of Am. Geophys. Union, Miami 
Beach, Fla. (17-21 April 1978) 

Quantitative Models of the 0 to 100 keV Mid- 
Magnetospheric Particle Environment 
Quant. Modeling of Magneto. Processes - A Chapman 
Conf., LaJolla Shores, Calif. (19-22 September 1978) 

The Calculation of Spacecra ft Potential - Comparison 
Between Theory and Observation 
USAF Acad., Spacecraft ChargingTechnol. Conf., 
Colo. Springs, Colo. (31 October - 2 November 1978) 

Modeling of the Geosynchronous Plasma 
Environment 

Spacecraft Charging Technol. Conf., USAF Acad., 
Colo. Springs, Colo. (31 October - 2 November 1978) 

Garrett, H. B., and Forbes, J. M. (Boston 
Coll., Chestnut Hill, Mass.) 

Three-Dimensional Mode! of the Thermosphere Tidal 
Structure 

Inti. Assoc, of Geomag. and Aeron. Mtg., Seattle, 
Wash. (22 August - 3 September 1977) 

Garrett, H. B., Capt., Smart, D. F.,and 
Shea, M. A. 

.4 Study of the Use of Interplanetary Magnetic Field 
and Plasma Measurements as a Predictor of 
Geomagnetic Activity 

Inti. Symp. on Solar-Terres. Phys./COSPAR Conf., 
Innsbruck, Aus. (29 May -10 June 1978) 

GlAMPAPA, M.S. (Steward Obsv., Tucson, Ariz.), 
LlNSKY, J. L. (JILA, Boulder, Colo.), 
SCHNEEBERGER, T. J., and WORDEN, S. P. 
Chromospheric Emission Lines in the Quiescent 
Sl>ectrnm of the Flare Star AD Leo 
151st Am. Astronom. Soc. Mtg., Austin, Tex. (8-11 
January 1978) 

GlAMPAPA, M. S. (Univ. of Ariz.)and WORDEN, 

S. P. 

The Effects of Stellar Chromospheric Activity on 
Metallicity Measurements 

152nd Am. Astronom. Soc. Mtg., Madison, Wis. (24-28 
June 1978) 

Hardy, D. A., Burke, W. J. (RegisCoU. Res. 
Ctr., Weston, Mass.). SHUMAN, B., VANCODR, 
R. and SMIDDY, M. 

Observations of the Aurorae Usi ng the DMSP a nd S.t-J 
Satellites 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 



100 


Hardy, D. A., Freeman, J. W., and Hills, 

H. K. (Rice Univ., Houston, Tex.) 

Evidence for Energetic O’ author X' Ions in the Labe 
Plasma at fi()K < 

Am. Geophvs. Union 1977 Spring Mtg., Wash., D. C. 
CIO May ;Uune 1977) 

HlLLS, H. K. (Rice Univ., Houston, Tex.), 
Hardy, D. A., and Freeman, J. W. (Rice 
Univ., Houston, Tex.) 

Hy Dependence of the Labe Plasma at 60 Ry 
Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 
CM) May-({June 1977) 

HUBBARD, E. , STRITTMATTER, P., W(X)LF, 
N., Heue. K. (Univ. of Ariz.), and WORDEN, S. 
P. 

Speckle Interferometry at StewartI Observatory 
152nd Am. Astronom. Soe. Mtg., Madison, Wis. (24-28 
June 1978) 

Hubbard, E., Reed, M., Strittmatter, 

P., HEGE, K. (Steward Obsv., Univ. of Ariz.), and 

Worden, S. P. 

Digital Speckle Interferometry to Measure the 
Angular Diameters at Faint Objects 
IAU Colloq. #50, High Angular Resolution Stellar 
Interferom., Coll. Pk., Md. CM) August -1 September 
1978) 

Huber, A., Pantazis, J., Vesprini, R. 

(EmmanuelColl., Boston, Mass.), RoTHWELL, P. 
L., Rubin, A. G., andMENG, C-I. (Univ. of 
Calif. Berkeley, Calif.) 

Initial Data Acquired from theSSJ/.t Electrostatic 
Analyzer on Hoard the DMSP Satellite 

1977 Fall Am. Geophys. Union Mtg., San Francisco, 
Calif. (5-9 December 1977) 

JASPERSE,J. R. 

Comparison Between the Theoretical and 
Experimental Photoelectron Flax at IfU Km 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Analytical Results tor the Photoelectron Flax Irani 
Roltzwann-Fokker Planck Theory 
1978 Fall Am. Geophys. Union Mtg., San Francisco, 
Calif. (4-8 December 1978) 

Johansen, J. M. (Emmanuel Coll., Boston, 
Mass.), BUONSANTO, M. J. (Boston Univ., 

Boston, Mass.), and KLOBUCHAR, J. A. 

The Variability of Ionospheric Time Delay 
Eff. of Iono. on Space and Terres. Sys., Naval Res. 
Lab., Arlington, Va. (24-26January 1978) 

Beacon Stud. COSPAR Symp., Florence, Italy (22-25 
May 1978) 

KARPEN, J. T. (Univ. of Md.), and WORDEN, S. 

P. 

Nucleosynthesis of Li' in Solar Flares 

Mtg. on Solar and Interplanet. Phys., Tucson, Ariz. 

(12-15 January 1977) 


Keil, S. L. 

The Height Dependence of SolarVelocity Fluctuations 
152nd Mtg. of Am. Astronom. Soe., Madison, Wis. 
(24-28 June 1978) 

KELCH, W. L., LlNSKY, J. L. (JILA, Boulder, 
Colo.), and WORDEN, S. P. 

Modeling of Chromospheric Activity in F-M Dtmrf 
Stars and the Sun 

151st Am. Astronom. Soc. Mtg., Austin, Tex (8-11 
January 1978) 

Kersley, L. Hajeb-Hoseinieh. H and 
Edwards, K. J. (Univ. Coll, of Wales, 
Aberystwyth, U. K.) 

ATS-6 Observations of Ionospheric!Protonospheric 
Electron Content and Flux 

Symp. ofEff. of Iono. on Space and Terres. Sys., Naval 
Res. Lab., Arlington, Va. (24-26January 1978) 

Kersley, L. and Klobuchar, J. A. 

A re rage Response of Protonospheric Electron Content 
to Geomagnetic Storm Activity 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Beacon Stud. COSPAR Symp., Florence. Italy (22-25 
May 1978) 

Klobuchar, J. A. 

Ionospheric Effects on Satellite Navigation and Air 
T rattle C ontrol Systems 

George Washington Univ., Wash., D. C. (25October 
1977); AGARD Lecture Ser. 93, Oslo, Norway, 8-9 
May 1978; London, Eng. (11-12 May 1978); Rome, Italy 
(15-16 May 1978) 

Klobuchar, J. A., Aarons, J., Weber, 

E., LUCENA, L., and MENDILLO, M. (Boston 
Univ., Boston. Mass.) 

Total Electron Content Changes Associated with 
Equatorial Irregularity Plumes 
Comsn. G, Natl. Rad. Sci. Mtg. of URSI, Boulder, 
Colo. (5-10 November 1978) 

Klobuchar, J. A., Buonsanto, M. J., 

MENDILLO, M. J. (Boston Univ , Boston, Mass.), 
and Johansen, J. M. (Emmanuel Coll., Boston, 

Mass.) 

The Contribution of the Plasmasphere to Total Time 
Delay 

Symp. on Eff. of Iono. on Space and Terress. Sys., 
Naval Res. Lab., Arlington, Va. (24-26January 1978) 

Klobuchar, J. A. . Clinch, J. R. (Univ. of 
Texas at Austin), and MENDILLO, M. J., Boston 
Univ,, Boston, Mass.) 

VHF Radio Ware Propagation Effects Observed 
During LAGOPEDO Ionospheric Modification 
Experiments 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 




101 


KLOBUCHAR, J. A., and JOHANSON, J. M. 
(Emmanuel Coll., Boston, Mass.) 

A Compariosn of Average Plasmaspherie Electron 
Content at Two Mid-Latitude Stations 
Am.Geophys. Union Mtg., Wash., D. C. (30May-3 
June 1977) 

Correlation Distance of Mean Daytime Total Electron 
Content 

USNC/URSI Mtg„ Stanford Univ., Stanford, Calif. 
(20-24 June 1977) 


KLOBUCHAR, J. A., RaSTOGI, R. G., and 
DESHPANDE, M. R. (Phys. Res. Lab., 
Ahmedabad, India) 

Near Equatorial Plasmaspherie Electron Content - 
Summer 1976 

Am. Geophys. Union Mtg., Wash., D. C. (30May - 3 
June 1977) 

Knecht, D. J., Hutchinson, R. 0., and 
Tsacoyeanes, C. W. 

The AFGL Magnetometer Network: A Brief 
Description 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Konig, P. J. Van Der Walt, A. J., 
Stoker, P. H., Raubenheimer, B. C., 

(Potchefstroom Univ. forC. H. E., Potchefstroom, S. 

Africa), Shea, M. A., and Smart, D. F. 

Vertical Cutoff Rigidity and the Intensity Distribution 
of Cosm ic Rays Near Cape Town 
15th Inti. Cosmic RayConf., Plovdiv, Bulgaria (13-26 
August 1977) 


LEITINGER, R., (Univ. of Graz, Aus.), ALLEN, 
R. S., Hartmann, G. K. <inst. fur Met. and 
Geophys., Graz, Aus ), and DONATELLI, D. D. 
(RegisColl., Weston, Mass,) 

Adaptive Mapping of Ionospheric Features 
Eff. of Iono. on Space and Terres. Sys., Naval Res. 
Lab., Arlington, Va. (24-26January 1978) 

LlNSKY, J. L. (Jt. Inst, for Lab. Astrophys., Natl. 
Bur. of Stds., Boulder, Colo.), and WORDEN, S. P. 
High Spectral Resolution K Line Observation of Active 
Chromosphere Stars 

149th Mtg. of Am. Astronom. Soc., Honolulu, Haw. 
(16-19 January 1977) 

Maple, E. 

Polarization of Geomagnetic Pulsations (0.21, to in 
Minute Periods) at +.54° Geomagnetic Latitude 
Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 
(30 May-3 June 1977) 

The Polarization of Geomagnetic Pulsations (0.2i to 
iS Minute Periods) at a Sub-Auroral Zone Station 
Inti. Assoc, of Geomag. and Aeron. IAGA Mtg., 
Seattle, Wash. (22 August - 3 September 1977) 


MENDILLO, M. (Boston Univ., Boston, Mass.), and 
KLOBUCHAR, J. A. 

F-Region Storm Morphologies Related to Trans- 
lonospheric Propagation 

AGARD/NATO Symp. on Op. Modeling of Aerosp. 
Prop. Envmt., Lisbon, Portugal (17-21 April 1978) 

F-Region Storm Morphologies Obtained from Satellite 
Radio Beacon Techniques 

COSPAR Beacon Stud. Symp., Florence, Italy (22-25 
May 1978) 

Mischke, C. F. W., Raubenheimer, B. 
C., Stoker, P. H., Van Der Walt, A. J. 

(Potchefstroom Univ. forC. H. E., Potchefstroom, S. 
Africa), SHEA, M. A., and SMART, D. F. 
Secular Variations in the Vertical Cutoff Rigidity as 
Measured by a Neutron Moderated Detector 
1978 Fall Mtg. of Am. Geophys. Union, San Francisco, 
Calif. (4-8 December 1978) 

Mullen, J. P., Bushby, A., Lanat, J., and 

PANTAJA, J. (Inst. Geophys., Lima, Peru) 
Gigahertz Scintillation at the Magnetic Equator 
Iono. Eff. Symp., Naval Res. Lab., Arlington, Va. 
(24-26 January 1978) 

N OVEMBER, L. J. , TOOMRE, J. (Univ. of Colo.), 
GEBBIE, K. B. (Natl. Bur. ofStds., Boulder, 
Colo.), and SIMON, G. W. 

Vertical and Horizontal Components of 
Supergranulation Velocity Fields Observed with 
OSO-S 

150th Mtg. of Am. Astronom. Soc., Atlanta, Ga. (12-16 
June 1977) 

Odom, D. B., Boar, T. I. S., Ill (Raytheon 
Co., Wayland, Mass.), and KLOBUCHAR, J. A. 

Un usual Scale Height Distribution NearF-Region 
Maximum Suggested by Incoherent Scatter and TEC 
Measurements 

Natl. Rad. Sci. Mtg., Univ. of Colo., Boulder, Colo. 

(9-13 January 1978) 

Pike, C. P., and Dandekar, B. S. 

Auroral Oval Dynamics and Substorm Occurrence 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Rastogl R. A. , Aarons, J. , Whitney, H. 
E., and Mullen, J. P. 

HF and VHF Scintillations Near the Magnetic 
Equator 

Comsn. G, Natl. Rad. Sci. Mtg. of URSI, Boulder, 
Colo. (5-10 November 1978) 

Rastogi, R. G.. Klobuchar, J. A., 

JOHANSON, J. M. (Emannuel Coll., Boston, 
Mass.), and BUSHBY, A., (Geophys. Inst, of Peru, 
Lima, Peru) 

Total Electron Content in the Equatorial Ionosphere 
1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 





102 


Rich, F. J., Burke, W.J. (RegisColl., Weston, 
Mass.), WlLDMAN, P. J. L., and SAGALYN, 

R. C. 

Electron Temperature Profiles Measured up to 8000 
Km by Sd-S 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 


Rothwell, P. L. 

A Dynamical Model,tor the Onset of Magnetospheric 
Snbstorvis 

1978 Am. Geophys. Union Mtg., Miami Beach, Fla. 
(17-21 April 1978) 


Rothwell, P. L., Rubin, A. G., and 
Yates, G. k. 

A Time-Dependent Simulation Model for S/mcecraft 
Charging 

Am. Geophys. Union 1977Spring Mtg . Wash., D. C. 
(30 May-3 June 1977) 

A Time-Dependent Com pater Code for Spacecraft 
Charging 

IEEE Symp., Seattle, Wash. (13-15 August 1977) 


Rothwell, P. L., and Yates, G. K. 

A Dynamical Mode! tor the Onset of Magnetospheric 
Substorms 

Chapman Conf. — Magneto. Substorms and Related 
Plasma Processes, Los Alamos Sci. Lab., Los Alamos, 
N. M. (9-13 October 1978) 

The Plasma Sheet and Precipitating Protons 
1978 Fall Mtg. of Am. Geophys. Union, San Francisco, 
Calif. (4-8 December 1978) 


Rubin, A. G u Garrett H. B., and 
Rothwell, P. L. 

ATS-!) and ATS-fi Potentials During Eclipse 
Spacecraft Charging Technol. Conf., USAF Acad., 
Colo. Springs, Colo. (31 October - 2 November 1978) 


Rubin, A. G., and Rothwell, P. L. 

Spacecraft Charging by Beams and Plasmas 
Am. Geophys. Union 1977 Spring Mtg., Wash. D. C. 
(30 May -3 June 1977) 


Rubin, A. G., Rothwell, P. L., and 
Yates, G. K. 

Reduction of Spacecraft Charging Using Highly 

Emissice Siuface Materials 

Iono. Eff. Symp., Arlington, Va. (24-26January 1978) 


Rush, C, M. 

Ionospheric Predictions: Methods and Results 
AGARD/NATO Symp. on Op. Modeling of Aerosp. 
Prop. Envmt,, Lisbon, Portugal (17-21 April 1978) 


SAGALYN, R. C. and BURKE, W. J. (Regis 
Coll., Weston, Mass.) 

Direct Observations of Con jugate Photoelectron 
Heating in the Winter Night-Side Ionosphere 
Am. Geophys. Union Mtg., Wash., D. C. (30May-3 
June 1977) 


Schneeberger, T. J. 

The Spectrum of T Tauri StarBM AND 

152nd Am. Astronom. Soc. Mtg., Madison, Wis. (24-28 

June 1978) 

Schneeberger, T. J., Worden, S. P., 

LlNSKY, J. L. , and MC CLINTOCK (JILA, 
Boulder, Colo) 

Simultaneous Photometry and Time Resol red Spectra 
of Flare Star AD Leo 

151st Am. Astronom. Soc. Mtg., Austin, Tex. (8-11 
January 1978) 

Shea, M.A. 

Solar-Terrestrial Physics — The Main Directions of 
Investigations, Data Collections and Data 
Dissemination (Invited Paper) 

P. N. Lebedev Physical Inst. Seminar, Moscow, USSR 
(3 October 1978) 

Solar-Terrestrial Physics Data Exchange (Invited 
Paper) 

Symp. of The Geophys. Comm., Pan Am. Inst, of 
Geography and History, Ottawa, Canada (27 
September - 1 October 1976) 

Shea, M.A., Garrett, H.B., and Smart, 

D.F. 

Correlations with Geomagnetic Activity- 
Interplanetary Magnetic Field and Plasma Data vs. 
Persistence 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Shea, M. A., and Smart, D. F. 

The Effects of Recent Secula r Variations of the 
Geomagnetic Field on Vertical Cutoft Rigidity 
Calculations 

15th Inti. Cosmic Rfcy Conf., Plovdiv, Bulgaria (13-26 
August 1977) 

A Comparison of the Characteristics of Solar Proton 
Events for the Last Two Solar Minima 
Inti. Symp. on Solar-Terres. Phys./COSPARConf., 
Innsbruck, Aus. (29 May -10 June 1978) 
Solar-Terrestrial Events DuringSTIP Intervals I and 
II (September-October 1975, 15 March -15 May 1976) 
(Invited Paper) 

Space Res. Inst. Seminar, Moscow, USSR (4 October 
1978) 

Research on Cosmic Ray Cutoffs - Calculations of 
Asymptotic Directions and Cutoff Rigidities in the 
Geomagnetic Field (Invited Paper) 

Nuclear Phys. Inst. Seminar, Moscow State Univ., 
Moscow, USSR (2 October 1978) 



103 


Shea, M. A., Smart, D. F., Arens, M. 

(Natuurkundig Labcratorium der Universiteit van 
Amsterdam, The Netherlands), BERCOVITCH, M. 
Nat. Res. Council of Canada, Ottawa, Canada), 
FU'CKINGER, E. (Physikalisches Institut der 
Universitat, Beni, Switzerland), HATTON, C. J. 
(Univ. of Leeds, Leeds, England), LAZUTIN, L. L. 

(PolarGeophys. Inst., Apatity, Murmansk Region, 
USSR), Lockwood, J. A. (Univ. of New 
Hampshire, Durham, NH), POMERANTZ, M. A., 
DUGGAL, S. P. (BartolRes. Foundation of the 
Franklin Institute, Univ. of Delaware, Newark, 
Delaware). ROHRS, K., WlBBERENZ, G. 
(Institut fur Reine und Angewandte Kemphysik, Kiel, 

FRG), Stoker, P. H., Konig, P. J. 

(Potchefstroom University for C. H, E,, 
Potchefstroom, South Africa), STORINI, M. 
(Laboratorio PlasmaSpazio - C. N. R., Rome, Italy), 
and TANSKANEN, P. J. (University of Oulu, Oulu, 
Finland) 

Conifnisite Re/xirt on Hie Relativistic Solar Proton 
Increase of 7 Mott HI'S 

1978 Fall Mtg. of Am. Geophys. Union, San Francisco 
Calif. (4-8 December 1978) 

Shea, M. A., Smart, D. F.,andCoFFEY, H. 
E. (WDCA forSolar-Terres. Phys., Boulder, Colo.) 
AS it in mil ry of S igti ifica nt Sola r-l n itiated E rents 
During STIP Intervals I and II 
Invited Paper, Comm, on Space Res. Symp. on Study 
of Travelling Interplanet. Phenom., Tel Aviv, Israel 
(7-18 June 1977) 

A Summary of Significant Solar-Terrestrial and 
I nterpla neta ry E rents Du ring the Retrospective World 
Interval at JO March - .i May 1976 
15th Inti. Cosmic Ray Conf., Plovdiv, Bulgaria (13-26 
August 1977) 

Simon, G. W., Rhodes, E. J., and Urich, 

R. K. (Univ. of Calif, at Los Angeles) 

Observations of Non -Radial P Mode Oscillations on 
the Sun 

Mtg. on Solar and Interplanet. Phys., Tucson, Ariz. 
(12-15 January 1977) 

Acoustic Spectroscopy at the Solar Envelope 
149th Mtg. of Am. Astronom. Soc., Honolulu, Haw. 
(16-19 January 1977) 

Smart, D. F. 

SILAF and Special Proton Events (Invited Paper) 
Symp. of the Geophys. Comm., Pan Am. Inst, of 
Geography and History, Ottawa, Canada (27 
September - 1 October 1976) 

The Prediction of Solar Proton Events (Invited Paper) 
1ZMIRAN Seminar, Moscow, USSR (5 October 1978) 

Smart, D. F., and Shea, M. A. 

Prediction of the Solar Proton Time-Intensity Profiles 
for the 10 April 1976 Event 
Comm, on Space Res. (COSPAR) Mtg., Tel Aviv, 
Israel (7-18 June 1977) 

The Use of Offset Dipole Coordinates for Interpolating 
Cosmic Ray Cutoff Rigidities in Three Dimensions 
15th Inti. Cosmic Ray Conf., Plovdiv, Bulgaria (13-26 
August 1977) 


Application of Elementary r 'iivm; ' Propagation and 
Co-Rotational Concepts t‘ Jar Proton Event 
Prediction 

15th Inti. Cosmic Ra” Corf, Plovidiv, Bulgaria (13-26 
August 1977) 

Cosmic Ray Cutoffs in Three E intensions ■ Difficulties 
with Stomier Theory 

1978 Spring Am. Geophys, Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

Current Status of Short-Term Solar Proton 
Predictions 

Inti. Symp. on Solar- Terres. Phys./COSPAR Conf., 
Innsbruck, Austria (29 May -10 June 1978) 

Smart, D. F., Shea, M. A., Lund, N., 
RaMUSSEN, I. L., BRYNAK, B., and 
WESTERGAARD, N. J. (Danish Space Res. Inst., 
Lyngby, Denmark) 

Preliminary Cosmic Ray Trajectory Calculations for 
the HEAO-C Satellite-Initial World Grid 
1978 Fall Am. Geophys. Union Mtg., San Francisco, 
Calif. (4-8 December 1978) 


Smiddy, M., Burke, W. J. (Regiscoil., 
Weston, Mass.) KELLEY, M. C. (CornellUniv., 
Ithaca, N. Y.), and LAI, S. T. (Logicon, Inc., 
Lexington, Mass.) 

Electric Fields at H igh Latitudes Near the Dawn-Dusk 
Meridian 

1978 Spring Am. Geophys. Union Mtg., Miami Beach, 
Fla. (17-21 April 1978) 

SMIDDY, M., and SAGALYN, R. C. 

Electric Fields at High Latitudes Near the Dawn-Dusk 
Meridian 

COSPAR Symp., Innsbruck, Aus. (29 May -10June 
1978) 

SMITH, E. R. (Boston Coll., Chestnut Hill, Mass.), 
and J ASPERSE, J. R. 

Comparison Between Theoretical (Boltzmann- 
Fokker-Planckl and Experimental Remits for the 
Photoelectron Flux 

1978 Fall Am. Geophys. Union Mtg., San Francisco, 
Calif. (4-8 December 1978) 

Snyder, A. L., Jr., Lt. Col. 

DMSP and Space Science 

Tech. Sem., Univ. of Texas at Dallas, Ctr. for Space 

Sci., Richardson, Tex. (30 June 1977) 

Ionospheric and Magneto spheric Modeling for Air 
Force Applications 

Quant. Modeling of Magneto. Processes, LaJolla 
Shores, Calif. (19-22 September 1978) 

Straka, R. M. 

Observations of the 21 August 1975 Proton Flare with 
the Haystack 120-Foot Radio Telescope 
150th Mtg. of Am. Astronom. Soc., Atlanta, Ga. (12-15 
June 1977) 



104 


Tarnstrom, G. L.. 

S/iectral Development of SolorCmh Burst* 

152nd Mtg. of Am. Astronom. Soc., Madison, Wis. 

(25-29 June 1978) 

Tarnstrom, G. L., and Guidice, D. A. 

One Minute hi the Life of n Solar Microwave Burst 
150th Mtg. of Am. Astronom. Soc., Atlanta, Gat 12-15 
June 1977) 

Weber, E. J., Buchau, J.,and Eather, R. 

H. (Boston Coll., Chestnut Hill, Mass.) 

Airborne All Sky Imaging of Airgloir and Aurora 
(ith Ann. Mtg. on Upper Atm. Stud, by Opt. Means, 
Aberdeen Univ., Aberdeen, Scotland (18-21 
September 1978) 

Weber, E. J., and Eather, R. H. (Boston 
Coll., Chestnut Hill, Mass.) 

All Skg Imaging of Equatorial Airgloir 

Am. Geophys. Union Spring Ann. Mtg., Wash., I). C. 

(JO May - J June 1977) 

Weber, F. L., Papagiannisl M. D. , (Boston 
Univ., Boston, Mass.), STRAKA, R. M., and 
BLEIWEISS, M. P. (NELC. San Diego. Calif.) 
Sola r Radio Maps at Eire Wa relengths in the Presence 
of a Large Corona! Hole 

Mtg. on Solar and Interplanet. F’hys., Tucson, Ariz. 
(12-15 January 1977) 

WEHINGER, P. A. (Royal Greenwich Obsv., 
Greenwich, England), WORDEN, S. P., and 
WYCKOFF, S. (Ohio State Univ.) 

Image Restoration of Techniques Applied to QSO 
Images 

151st Am. Astronom. Soc. Mtg., Austin, Tex. (8-11 
January 1978) 

Whalen, J. A., and Wagner, R. A. 

Mapping of Plasma Sheet Precipitation Via the 
Continuous Aurora and Auroral E Layer 
1977 Spring Mtg. of Am. Geophys. Union, Wash., D. C. 
(JO May - 2 June 1977) 

Dynamics of the Band of Continuous Aurora and 
Auroral E-Layer 

Natl. Rad. Sci. Mtg., Boulder, Colo. (9-1J January 
1978) 


Whitney, H. E. 

Spaced Receiver Measurements of Intense Equatorial 
Scintillations 

lono. Eff Symp., Naval Res. Lab., Arlington, Va. 
(24-26 January 1978) 

Effect of the Equatorial Ionosphere on Satellite 
Communications 

Inti. Symp. on Rad. Waves and the lono., URSI Gen. 
Asbly., Helsinki, Finland (1-8 August 1978) 


Whitney, H. E„ Buchau, .I., and Weber, 

E.J. 

The Evolution of Scattering Equatorial E-Region 
Irregularities and Resultant Effects on Trans- 
Ionospheric Radio Wares 

AGARD Mtg. on Aspects of EM Wave Scattering in 
Rad. Comm., Dept. ofTransp., Cambridge, Mass. (8-7 
October 1977) 

WOODMAN, R. F. (Max-Planek Inst, fur Aeron., 
I.indau, Fed. Rep. ofGer.), and BasU, S. 
Com/sirison Between In Situ Spectral Measurements 
of Equatorial E-Region Irregnlaritiesand Backscatter 
Observations at .1M Wavelength 
Am. Geophys. Union 1977 Spring Mtg., Wash., D. C. 
CIO May -8 June 1977) 

Worden, S. P. 

An Empirical Technique tor Reconstructing Dirge 
Telescope Diffraction Limited I mages 
Inti. Astronom. Union Mtg., Grenoble, Fr. (24-JO 
August 1970) 

Solar a ml Stellar Speckle I nterfcmmetry 
Inv. Pa|H*r, I50th Mtg. of Am. Astronom. Soc., 
Atlanta, Ga. (12-15 June 1977) 

High Spatial Resolution Optical Observing Through 
the Earth's Atmosphere 

1978 AFSCVNACMETSci. and Engrg. Svmp., San 
Diego. Calif. (17-19 October 1978) 

Worden, S. P., and Simon, G. W. 

Oh the Origin of Oscillations in the Solar Limb 
Position 

150th Mtg. of Am. Astronom. Soc., Atlanta, Ga. (12-15 
June 1977) 


TECHNICAL REPORTS 
JULY 1976 - DECEMBER 1978 


Aarons, J., Buchau, J. Mullen -J. P., 
Weber, E. J., 1st Lt., Whalen,.)., and 
Whitney, H. E. 

(iron ml and Airborne Scintillation Studies tor 
AESATCOM DTAEIIOTA-E 
A FGL-TR-76-0164 (2 August 1976) 

Aarons, J., Mullen, J., Whitney, H., 

and MARTIN, E. (EmmanuelColl., Boston, Mass.), 
Bhavnani, K., Whelan, L. (Logicon, inc„ 
Bedford, Mass.) 

A High-Latitude Empirical Mode! of Scintillation 
Excursions: Phase I 
AFGL-TR-76-0210 (17 September 1976) 

AHMED, M. (RegisColl., Weston, Mass.), and 

Sagalyn, R. C. 

Topside Ionospheric Trough Morphology id Mid- and 
High-Latitudes 

Compilation of Pap. Presented by Space Phys. Div. at 
lono. Eflf. Symp. (IES 1978), AFGL-TR-78-008015 
April 1978); AFGL-TR-78-0110(May 1978) 



105 


Aixf.n. R. S. 

Cdnxiderations Relative to Adapting TRANSIT 
Observations to Predict iiit/ Radar Rouge Comet ion 
AFGL-TR-77-0004 (12January 1977) ' 

Allen, R. S., Donatelli, D. E. (Regis Coil., 

Weston. Mass.), HARTMANN, G. K, (Inst, fur 
Aeron., Lindau/Hartz, Fed. Rep. ofGer.), and 
LEITINGER, R. (Univ. ofGraz, Aus.) 

Adoptive Mopping of Mid-Latitude Ionosphere 
AFGL-TR-77-0176 0I August 1977) 

Allen, R. S., Donatelli, D. E.,and 

PlCARDI, M. C. (Regis Coll. Res. Ctr., Weston, 
Mass.) 

Correetion tor Ionospheric Retraction torCORRA 
DANE 

AFGL-TR-77-0257 (IK November 1977) 

BaKSHI, P. (Boston Coll, Chestnut Hill, Mass.), and 

Barron, W. 

Prediction id the Proton Fine Magnitudes from Radio 
Horst Data 

AFGL-TR-7K-0100 (April 197H) 

Banshidhar. Vaher, N. M., HariOm 

Vats, DESHPANDE, M. R. (Phys. Res. Lab., 
Ahmedabad, India), and RaSTOGI, R. G. 

Effects id Ionospheric Scintillations on Satellite 
Communication 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Svmp. (IES 197K), AFGL-TR-00K0(5 April 
197K) 

BAST, S. (Emmanuel Coll., Boston, Mass.), and 

Aarons, J. 

Equatorial Irregularity Campaigns. Part I: 

Cominted Scintillation and Radar Rnrkxcatter 
Measurements in October 1976 
AFGL-TR-77-0264 (2:1 November 1977) 

Base, S., and Kelley, M. C. (Cornell Univ., 
Ithaca, N. Y.) 

A Review of Recent Studies at Equatorial F-Region 
Irregularities and Their Impact on Scintillation 
Mislet mg 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 197K), AFGL-TR-7K-0080(5 
April 197K) 

BASU, S. (EmmanuelColl., Boston, Mass.), 

Whitney, H., Aarons, J., and McClure, 

J. P. (Univ. of Texas at Dallas) 

Large and Small Scale Properties of Nighttime 
Equatorial Irregularities from Scintillations and 
Radar Backscatter Measurements 
Compilation of Pap. Presented by Space Phys. Div, at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 

BINDER, 0. H. (Inst. fur Reine Und Angewandte 
Kemphysik der Christian Albrechts Univ. Kiel, Ger.), 

Shea, M. A., and Smart, D. F. 

An Extended Set of Cosmic Ray Variational 
Coefficients for European Cosmic Ray Stations 
AFGL-TR-77-0057 (3 March 1977) 


Buchau,J., Aarons, J., Mullen, J. P., 
Weber, E. j., Whalen, J. A., Whitney, 

H. E., andCRAMPTON, E. E., JR. (MitreCorp., 
Bedford, Mass.) 

A mpUtude Scintillation Studies in the Polar Region 
on 2.5 0 MHz 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 

BUCHAU, J., and HALL, W. N. 

Remote Ionospheric Monitoring 
Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 

Bijchau, J., Weber, E. J., and Me Clure, 

J. P. (The Univ. of Texas at Dallas) 

Radio and Optical Diagnostics Applied to an Isolated 
Equatorial Scintillation Event 
Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 

Burke, W. J., Donatelli, D. E., (Regis 

Coll., Res., Ctr., Westom Mass.), SAGALYN, K. 

C. , and KELLEY, M. C. (Cornell Univ., Ithaca, N. 
Y.) 

Large Amplitude Imgularities at Low Latitudes in 
the Topside Ionosphere 
AFGL-TR-77-0263 (28 November 1977) 

Burke, W. J. (RegisColl. Res. Ctr., Weston, 
Mass ), and SAGALYN, R. C. 

Thermal Structure of the Topside Ionosphere Observed 
by INJUN 5 During an Intense Magnetic Storm 
AFGL-TR-77-0261 (28 November 1977) 

BURKE, W. J. (Regis Coll. Res. Ctr., Weston, 
Mass ), SAGALYN, R. C., and KANAL, M. 
(Univ. of Lowell, Ctr. for Atm. Res., Lowell, Mass.) 
Thermal and Hyperthermal Electron Distributions in 
the Midnight Sector of the Winter Topside Ionosphere 
AFGL-TR-77-0262 (28 November 1977) 

BURKE, W. J. (RegisCol)., Weston, Mass.), and 

Smiddy, M. 

The Behavior of Gridded Spherical and Planar 
Electron Probes in a Non-Marwellian Plasma 
AFGL-TR-78-0064 (16 March 1978) 

CASTELLI, J. P., and TARNSTROM, G. L. 
Solar Radio Burst Energies for March-April 1976 
Contributed Pap. to the Study of Travelling 
Interplanet. Phen./I977 (Proc. of COSPAR Symp. B, 
Tel Aviv, Isr., June 1977), AFGL-TR-77-0309(29 
December 1977) 

A Catalog of Proton Eivuts 1966-1976 Having Non- 
Classical Solar Radio Burst Spectra 
AFGL-TR-78-0121 (16 May 1978) 




106 


COFFEY, H. E. (World Data Ctr. A for Solar- 
Terres. Phys., NOAA, Boulder, Colo,), and SHEA, 

M. A. 

Directory of Solar-Terrestrial Physics Monitoring 
Stations 

AFGL-TR-77-0255 (Monsee Sp. Pub. No. 1) 
(November 1977) 

DoNATELLI, D. E. (RegisColl. Res. Ctr., 
Weston, Mass.), and ALLEN, R. S. 

Temporal Variability of Ionospheric Refraction 
Correction 

Compilation of Pap. Presented bv Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 

EIS, K. E. (Air Wea. Serv ), KLOBUCHAR, J. 
A., and Malik, C. 

On the Installation, Operation, Data Reduction, and 
Maintenance o/VHF Electronic Polarirnetersfor 
Total Electron Content Measurements 
AFGL-TR-77-0 130 (31 May 1977) 

ElS, K. E., CAPT., and RICHARD, R. C., 
SSGT. (AWS, Det. 2, 12th Wea. Sq.) 

An Observer's Manual for the Air Force Swept 
Frequency Interferometric Radiometer 
AFGL-TR-78-0048(21 February 1978) 

Garrett, H. B., IstLt. 

Analysis of PenumbraI Eclipse Data 

Proc. of Spacecraft Charging Technol. Conf., AFGL- 

TR-77-0051 (24 February 1977) 

Modeling of the Geosynchronous Orbit Plasma 

Environment - Part l 

AFGL-TR-77-0288 (14 December 1977) 

Effects of a Time-Varying Photoelectron Flux on 
Spacecraft Potential 
AFGL-TR-78-0119 (15 May 1978) 

Spacecraft Potential Calculations - A Model 
AFGL-TR-78-0116 (5 May 1978) 

Garrett H. B., Capt., Mullen, E. G., 

ZlEMBA, E. (ASEC Corp., Burlington, Mass.), and 
DEFOREST, S. E. (U. of Calif., San Diego, Calif.) 
Modeling of the Geosynchronous Orbit Plasma 
Environment - Part J. ATS-5 and ATS-fi Statistical 
Atlas 

AFGL-TR-78-0304 (30 November 1978) 

Garrett, H.B., Capt., Pavel, A. L., 
Capt., and Hardy, D. A., 1st Lt. 

Rapid Variations in Spacecraft Potential 
AFGL-TR-77-0132 (6 June 1977) 

Garrett, H. B., Capt, and Rubin, A. G. 

Spacecraft Charging at Geosynchronous Orbit - 
Solution for Eclipse Passage 
AFGL-TR-78-0122 (15 May 1978) 

Gaunt, D. N. 

The Sagamore Hill Sweep Frequency Interferometric 
Radiometer Used for Solar Studies in the Dekametric 
Band 

AFGL-TR-76-0194 (23 August 1976) 


Guidice, D. A. 

Polarization Spectra of Centimeter - Wavelength Solar 
Bursts Using Whole-Sun Observations 
AFGL-TR-76-0295 (8 December 1976) 


JOHANSON, J. M. (Emmanuel Coll., Boston, 
Mass.), BUONSANTO, M. J. (Boston Univ.), and 

Klobuchar, J. A. 

The Variability of Ionospheric Time Delay 
Compilation of Pap. Presented by the Space Phys. Div. 
at lono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 


JURSA, A. S. 

Introduction 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 


Katz, A. H., GROSSI, M. D. (RaytheonCo., 
Wayland, Mass.) ALLEN, R. S., and 
DONATELLI, D. E. (Regis Coll., Weston. Mass.) 
Adaptive Correction of the Effect of the Ionosphere on 
Range Determination by Terrestrial Radars 
Compilaton of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 


KERSLEY, L., HaJEB-HOSSEINIEH, H., and 
Edwards, K. J. (Univ. Coil, of wales, 
Aberystwyth, U. K.) 

ATS-6 Observations of Ionospheric/Protonospheric 
Electron Content and Flux 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFCL-TR-78-0080(5 
April 1978) 


Klobuchar, J. A. 

Mid-Latitude Total Electron Content and Slab 
Thickness 

AFGL-TR-77-0065( 10 March 1977) 

Klobuchar, J. A., Buonsanto, M. J., 
MENDILLO, M. J. (Boston Univ.), and 
JOHANSON, J. M. (Emmanuel Coll., Boston, 

Mass.) 

The Contribution of the Plasmasphere to Total Time 
Delay 

Compilation of Pap, Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080 (5 
April 1978) 


Klobuchar, J. A., and Johanson, J. M. 

(Emmanuel Coll., Boston, Mass.) 

Correlation Distance of Mean Daytime Electron 
Content 

AFGL-TR-77-0185 (22 August 1977) 



107 


LEITINGER, R., (Inst, fur Met. undGeophys,, 
Univ, Graz, Graz, Aus.), ALLEN, R. S., 
DONATELLI, D. E, (Reps Coll. Res. Ctr 
Weston, Mass.), and HARTMANN, G. K. (Max- 
Planek-Inst. fuer Aeron., Katlenburg-Lindau, Fed. 
Rep. ofGer.) 

Adaptive Mapping of Ionospheric Features 
Compilation of Pap. Presented by Space Phys. Div. at 
lono. Eff. Symp. (1ES 1978), AFGL-TR-78-0080(5 
April 1978) 

MENDILLO, M., CHACKO, C., and LYNCH, 
F., (Boston Univ., Boston, Mass.), and WlLDMAN, 

P. J. L. 

Attempts to Predict Trough/Plasmapause Boundaries 
in Real Time 

Compilation of Pap. Presented by Space Phys. Div, at 
lono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 

Mullen, J. P., and Bushby, A., Lanat, 

J., PANTOJA, J. (Inst. Geofisico Del Peru, Lima, 
Peru) 

Gigahertz Scintillation at the Magnetic Equator 
Compilation of Pap. Presented by Space Phys. Div. at 
lono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 

NeIDIG, D. F., DE MaSTUS, H. L., and 
WlBORG, P. H. 

Flares, Force-Free Fields, Emerging Flux, and Other 
Phenomena in McMath H91.I (September 197?) 
AFGL-TR-78-0194 <9 August 1978) 

Pavel, A. L., Capt. (Ed.) 

SCATHA Satellite Instrumentation Report: Thermal 
Plasma Analyzer: Rapid Scan Particle Detector; 
Electron Beam System: Positive Ion Beam System 
AFGL-TR-76-0207( 10 September 1976) 

Pavel, A. L., andCiPOLLA, J. A., 
Silevitch, M. B., Golden, K. I. 

(Northeastern Univ., Boston, Mass.) 

Nuclear Burst Plasma Injection into the 
Magnetosphere and Resulting Spacecraft Charging 
Proe. of Spacecraft Charging Technol. Conf., AFGL- 
TR-77-0051 (24 February 1977) 

Pike, C.P. 

Executive Summary (Session l) 

Proc. of Spacecraft Charging Technol. Conf., AFGL- 
TR-77-005I (24 February 1977) 

Pike, C. P., and Lovell, R. R., Eds. (NASA 
Lewis Res. Ctr., Cleveland, Ohio) 

Proceedings of the Spacecraft Charging Technology 
Conference 

AFGL-TR-77-0051 (24 February 1977) 

RASTOGI, R. G., DESHPANDE, M. R., and 
OM VATS, H. (Phys. Res. Lab., Ahmedabad, India) 
Equatorial Ionospheric Scintillations in the Indian 
Zone 

Compilation of Pap. Presented by Space Phys. Div. at 
lono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 


Reilly, A. E. 

Analysis of Sweep Frequency Oblique Polar Region 
High Frequency Radio Propagation Measurements 
AFGL-TR-77-0102 (27 April 1977) 

RICH, F. J. (Regis Coll., Weston, Mass.), and 
WlLDMAN, P. J. L. 

A Model for the Electrical Cu rrent Collected by a 
Planar Aperture Ion Collector until a Partially 
Blocked Field of View 
AFGL-TR-77-0096 (25 April 1977) 

Rothwell, P. L., Rubin, A. G.,and 
Yates, G. fc. 

A Simulation Model of Time-Dependent Plasma- 
Spacecraft I nteractions 

Proc. of Spacecraft Charging Technol. Conf., AFGL- 
TR-77-0051 (24 February 1977) 

Rothwell, P. L., and Yates, G. K. 

A Dynamical Model for the Onset of Magnetospheric 
Substorms 

A FG L-TR-78-0306 (13 December 1978) 

SAGALYN, K. C., and BURKE, W. J. (Regis 
Coll. Res. Ctr., Weston, Mass.) 

INJUN !> Observations of Vehicle Potential 
Fluctuations at JSOO Km 

Proc. of Spacecraft Charging Technol. Conf., AFGL- 
TR-77-0051 (24 February 1977) 

Shea, M. A. Smart, D. F., and Wu, S. T., 
(Univ. of Ala.), Eds. 

Contributed Papers to the Study of Travelling 
Interplanetary Phenomenal 1977 
(Proc. of COSPAR Symp. B, Tel Aviv, Isr., June 1977), 
AFGL-TR-77-0309 (29 December 1977) 

SlZOO, A. H., and WHALEN, J. A. 

Lightning and Squall Line Identification from DMSP 

Satellite Photographs 

AFGL-TR-76-0256 (28 October 1976) 

Smiddy, M. .Sagalyn, R., Sullivan, W., 

WlLDMAN, P., and ANDERSON, P., RICH, F. 
(Regis Coll., Weston, Mass.) 

The Topside Ionosphere Plasma Monitor (obie, i.ror 
the Block 5DI Flight ■! DMSP Satellite 
AFGL-TR-78-0071 (22 March 1978) 

Space Physics Division 

Compilation of Papers Presented by the Space Physics 
Division at the Ionospheric Effects Symposium (IES 
19711) 

AFGL-TR-78-0080 (5 April 1978) 

Straka, R. M. 

High Resolution Solar Radio Activity Investigations 
AFGL-TR-77-0247 (8 November 1977) 

Weber, E. J. 

Propagation Velocities of Small Amplitude 
Disturbances in Multi-Ion Plasmas 
Contributed Pap. to Study of Traveling Interplanet. 
Phen. 1977 (Proc. of COSPAR Symp. B, Tel Aviv, Isr , 
June 1977), AFGL-TR-77-0309 (29 December 1977) 


108 


Weber, E. J.,Capt.. Buchau, J., 

EATHER, R. H. (Boston Coll, Chestnut Hill, 
Mass.), and LLOYD, J. W. F. 

La rge Scale Optical Mapping of the Ionosphere 
AFGL-TR-77-0236 (21 October 1977) 

Whitney, H. E. 

Spaced Receiver Measurements of Intense Equatorial 
Scintillations 

Compilation of Pap. Presented by Space Phys. Div. at 
Iono. Eff. Symp. (IES 1978), AFGL-TR-78-0080(5 
April 1978) 

WlLDMAN, P. J. L. 

Studies of Low Energy Plasma Motion, Results and a 
New Technique 

AFGL-TR-76-0168(25June 1976) 

Whitney, H. E., Buchau, J., Johnson, 

A. L. (AFAL, Wright-Patterson AFB, Oh.), 

Mullen, J. P., and Weber, E. J., Capt. 

Report on Pern Scintillation Tests - October 197H and 
March HIT7 

AFGL-TR-77-0282 (8 December 1977) 


CONTRACTOR JOURNAL ARTICLES 
JULY 1976 • DECEMBER 1978 

AKASOFU, S.-I. (Geophys. Inst., Univ. of Alaska) 
Magnetosphere a nd Magnetospheric Substorm 
Solar Phys., Vol. 47(1976) 

Recent Progress in Studies of DMSP Auroral 
Photographs 

Space Sci. Rev., Vol. 19(1976) 

BASU, S.. and KELLEY, M. C. (Cornell Univ., 
Ithaca. N. Y.) 

Review of Equatorial Scintillation Phenomena in 
Light of Recent Developments in the Theory and 
Measurement of Equatorial Irregularities 
J. of Atm. andTerres. Phys,, Vol. 39, No. 9/10(1977) 

BELL, B., and Noel, G. (Harvard Coll. Obsv., 
Cambridge, Mass.) 

Intensity of the EeXVEmission Line Corona, The 
Level of Geomagnetic Activity, and the Velocity of the 
Solar Wind 

J. of Geophys. Res., Vol. 81, No. 25(1 September 1976) 

Deehr, C. S., Winningham, J. D., 

Y ASUHARA, r . (The Univ. of Texas at Dallas), and 
AKASOFU, S.-I. (Geophys. Inst., Univ. of Alaska) 
Sim ulta neons Observations of Discrete and Diffuse 
Auroras by the ISIS .’Satellite and Airborne 
lustra meats 

J. of Geophys. Res., Vol. 81 (1976) 

Kamide, Y., Burch, J. L., Winningham, 

J. D. (The Univ. ofTexasat Dallas), and AKASOFU, 
S.-I. (Geophys. Inst., Univ. of Alaska) 

Dependence of the Latitude of the Cleft on the 
Interplanetary Field and Substorm Activity 
J. of Geophys. Res., Vol. 81 (1976) 


Kamide, Y., Perreault, P. D., Akasofu, 

S.-I,, and WlNNINGHAM, J. D. (Geophys. Inst., 
Univ. of Alaska) 

Dependence of Substorm Occurrence Probability on 
the Interplanetary Magnetic Field and on the Size of 
the Auroral Oval 

,J. of Geophys. Res., Vol. 82, No, 35(1 December 1977) 

KOUTCHMY, S., and STELLMACHER, G. (Inst, 
of Astrophys., Paris, Fr.) 

Photometric Study of Chromospheric and Coronal 
Spikes Observed During the Tola! Solar Eclipse of -to 
June, 197.1 

Solar Phys., Vol. 49(1976) 

Photospheric Famine 
Astron. Astrophys., Vol. 67(1978) 

M.ARISKA, J. T. (Smithsonian Ctr. for Astrophys., 
Cambridge, Mass.) 

Analysis of Extreme l 'Itmdiet Observations of a 
Polar Corona! Hole 

The Astrophys. J., Vol. 226 (1 October 1978) 

MENG, C.-I, HoLZWORTH, R. H., and 
AKASOFU, 5.-1. (Geophys. Inst., Univ. of Alaska) 
Auroral Circle-Delineating the Poleward Houndary of 
the Quiet Auroml Belt 

J. of Geophys. Res., Vol. 82, No. 1 (1 January 1977) 

MENZEL, D. H. (Harvard Univ., Harvard Coll. 
Obsv., Cambridge, Mass.) 

Superstars and the Black-Hole Myth 

Memoires Soc. Royale des Sci. de Liege, O' serie, tome 

IX (1976) 

P.APAGIANNIS, M. D., and KOGUT, J. A. 
(Trustees of Boston Univ., Boston, Mass.) 

A Simple Derivation of Microwave Solar Brightness 
Temperatnresand Polarizations from Thermal 
Regions 

Soiar Phvs., Vol. 48 (1976) 

Sellers, B., Hanser, F. A., Morel, P. 

R., and Hl'NERWADEL, J. L. (Panamet.. Inc., 
Waltham, Mass.) 

A H igh-Time Resolution Spectrometer for 0.05 to 500 

keV Electrons a nd Protons 

Am. Inst, of Aeronaut, and Astronaut., N. Y., N. Y. 

Shepherd, G. G., Whitteker. J. H., 
Winningham, J. D., Hoffman, J. F., 
Mayer, E. J., Brace, L, H., Burrows, J. 

R., and COGGER, L. L. (The Univ. ofTexasat 
Dallas) 

The Topside Magnetospheric Cleft Observed from the 

ISIS J Spacecraft 

J. of Geophys. Res., Vol. 81 (1976) 

Stiles, G. S., Hones, E. W., 
Winningham, J. D., Lepping, R. P., and 

DELANA, B. S. (The Univ. ofTexasat Dallas) 
lonosonde Observations of the Northern 
Magnetospheric Cleft During December 1971 and 
January 1975 

J. of Geophys. Res., Vol. 82(1977) 




109 


WlNNINGHAM, J. D., SPEISER, T. W., 
Hones, E, W,, Jr., Jeffries, R. A., 
Roach, W. H., Evans, D. S., and 

STENBAEK-NiELSEN, H. C. (Univ. ofTexasat 
Dallas) 

Rocket-Borne Measurements of the Dayside Cleft 
Plosion: The TORDO Experiments 
J. ofGeophys. Res., Vol. 82, No. 13(1 May 1977) 


CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 - DECEMBER 1978 

Ahmad, I. A., and Withbroe, G. L., 

(Smithsonian Inst., Cambridge, Mass.) 

£7 V A not if sis of Polo r Pin mes 
AFGL-TR-77-0i67 (3 August 1977) 

Ahmeil M., Anderson, P. B., Burke, W. 
J., and RlCH, F. J. (Regis Coll., Weston, Mass.) 
Development nod Application of Electrical and 
Mechanical Prototype Instruments for Space 
Environment Studies 
AFGL-TR-77-0119(31 May 1977) 

AKASOFU, S.-I. (Geophys. Inst., Univ., of Alaska) 
Investigation of the Phenomenology of the Arctic 
Ionosphere and its Relation to the Phenomenology of 
Arctic Precipitation 
AFGL-TR-78-0269 (September 1978) 

ALBERCA, L. F. (Observatorio Del Ebro, Tortosa, 
Spain) 

Ionospheric Electron Production Rate for Grazing 
Incidence at the Ebro Observatory 
AFGL-TR-78-0044 (29 December 1977) 

ARTAC, E., andTULUNAY, Y. K. (Mid. East 
Tech. Univ., Ankara, Turkey) 

Ionospheric Total Electron Content Measurements 
from Turkey During the Solar Eclipse of J9 April 1976 
AFGL-TR-78-0299 (31 December 1977) 

BADILLO, V. L. (Manila Obsv,, Manila, 
Philippines) 

Possible Fermi Mechanism of Solar Cosmic Rays 
AFGL-TR-76-0193 (16 August 1976) 

Low Latitude PC .land PCi Micropulsations 
AFGL-TR-77-0294 (28 October 1977) 

BAKSHI, P., and KALMAN, G. (BostonColl., 
Chestnut Hill, Mass.) 

Predicting Proton Spectra and Riometer Absorption 
from and Theoretical Modelling for U-Shaped Solar 
Flare Radio Bursts 
AFGL-TR-78-0055 (February 1978) 

Basu. S., Basu, S., Johanson, J., 

Mac Kenzie, E., and Hagan, M. P. (The 

Trustees of Emmanuel Coll., Boston, Mass.) 

Study and Analysis of Irregularities, Total Electron 
Content, and Scintillations 
AFGL-TR-78-0263 (October 1978) 


Basu, S., Cantor, F. M., Johnson, J., 
Mac Kenzie, E., and Hagan, M. P. (The 

Trustees of Emmanuel Coll., Boston, Mass.) 

Study and Analysis of Total Electron Content and 
Scintillation Data 
AFGL-TR-76-0260 (October 1976) 

Bell, B., MENZEL, D. H. , and WOLBACK, J. 
G. (Harvard Coll. Obsv., Cambridge, Mass.) 
Research Study on Dynamics of the Solar Atmosphere 
AFGL-TR-76-0267 (October 1976) 

Bellew. W. F., Cantor, C. J., and 

HAGAN, M. P. (The Trustees of Emmanuel Coll., 
Boston, Mass.) 

Investigation of Micropulsation Activity 1. MAGAF 
System Additions. 2. Data Analysis 
AFGL-TR-76-0244 (August 1976) 

Investigation of Micropulsation Activity. 1. MAGAF 
System Additions. 2. Data Analysis 
AFGL-TR-77-0275 (December 1977) 

Investigations of Micropulsation Activity 
AFGL-TR-78-0312 (November 1978) 

Bibl, K., Reinisch, B. W., and Smith, S. 

(Ctr. for Atm. Res., Univ. of Lowell, Lowell, Mass.) 
Digital Ionospheric Sounding in the Arctic 
AFGL-TR-77-0162 (July 1977) 

Digital Ionospheric Sounding in the Arctic 
AFGL-TR-78-0109 (May 1978) 

Brown, J. C.. Canfield, R. C., and 
Robertson, M. N. (Univ. of Calif.) 

Ha Profiles from Electron-Heated Solar Flares 
AFGL-TR-78-0034 (26 January 1978) 

CHACKO, C., C., and MENDILLO, M. (Boston 
Univ.) 

High Latitude Ionospheric Gradients and Their 
Relationships to Auroral and Magnetospheric 
Boundaries 

AFGL-TR-78-0092G) (December 1977) 

Cipolla, J. W., Golden, K. I., Pavel, A. 

L., and SlLEVITCH, M. B. (Northeastern Univ., 
Boston, Mass.) 

Nuclear Burst Induced Shock Wave Modelling of 
Energetic Electron Injection into the Magnetosphere: 
Application of Streaming Plasma Instabilities to 
Shock Structures 
AFGL-TR-76-0186 (31 July 1976) 

DALGARNO, A., and CONSTANTINIDES, E. 
(Smithsonian Astrophys. Obsv., Cambridge, Mass.) 
Calculations Pertaining to the Energy Balance and 
Plasma Motions in the Ionosphere 
AFGL-TR-76-0163 (June 1978) 

De FOREST, S. E. (Inst, for Pure and Appl. Phys. 
Sci., Univ. of Calif., San Diego, Calif.) 

Speci fication of Geosynchronous Plasma 
Environment 

AFGL-TR-77-0031 (1 February 1977) 



110 


Devane, J. F., Rev., Johnson, S. J. E., 

and DALRYMPLE, R. (Bostonf oil., Chestnut Hill, 
Maas.) 

hi vestigation of Magnetic Field Phenomena in the 
Ionosphere 

AFGL-TR-76-0230 (September 1976) 

Douson-Prince, H. W., Hedeman, E. R., 

and MOHLER, 0. C. (McMath-HulbertOb8v.,The 
Univ. of Mich.) 

Surrey and Comparison of Solar Activity and 
Energetic Particle Emission in 1970 
AFGL-TR-77-0222 (30 September 1977) 

Study of Geomagnetic Storms and Solar Flares in the 
Years of Increasing Solar Activity, Cycles Wand JO 
(1955-1957, 1905-1969) 

AFGL-TR-78-0267 (31 October 1978) 

Solar and Geophysical Associations with the Principal 
Energetic Particle Events in 1971 and 197J 
AFGL-TR-78-0266 (31 October 1978) 

DU LONG D. D. (RegisColl. Rea. Ctr., Weston, 
Mass.) 

Reduction of the Uncertainty of Radar Range 
Correction 

AFGL-TR-77-0125 (1 June 1977) 

Du Long, D. D. (Regis Coll. Res. Ctr., Weston, 
Mass.), and ALLEN, R. S. 

Specification of Rada r Error for ADCOM Rada rs with 
Adaptive Modeling 
AFGL-TR-76-0037 (20 September 1976) 

EATHER, R. H. (KEOConsult., Newton, Mass.) 
Imaging All-Sky Photometer System 
AFGL-TR-77-0155 (June 1977) 

Fontheim, E. G., Hwang, K. S., andONG, 
R. S. B. (The Univ. of Mich.) 

Nonlinear Analysis of Plasma Instability Excited by 
the Auroral Electrojet 
AFGL-TR-78-0022 (24 January 1978) 

Golden, K. I., Cipolla, J. W., Jr., and 

SlLEVITCH, M. B. (Northeastern Univ., Boston, 
Mass.) 

Nuclear Burst Induced Shock Ware Modeling of 
Energetic Electron Injection into the Magnetosphere 
AFGL-TR-78-0265 (15 July 1977) 

GREBENKEMPER, C. J. (Rad. Astron. Inst., 
Stanford Univ., Stanford, Calif.) 

Fine Structure on the Sun at J.9 Cm 
AFGL-TR-76-0307 (16 December 1976) 

HANSER, F. A., and SELLERS, B. (Panamet., 
Inc., Waltham, Mass.) 

An Electrostatic Analyzer for an Air Force Satellite 
Payload - Evaluation of In-Flight Operation 
AFGL-TR-76-0203 (July 1976) 

Harel, M.. Wolf, R. A., Rieff, P. H.,and 

HlLLIS, H. K. (William Marsh Rice Univ., 
Houston, Tex.) 

Study of Plasma Flow Near the Earth's Plasmapause 
AFGL-TR-77-0286 (28 November 1977) 


Harvey, K. L., and Martin, S. F. (Spectra 
Opt., Sylmar, Calif.) 

Ephemeral Active Regions During the Solar 
Minimum 

AFGL-TR-76-0266 (28 October 1976) 

Holeman, E. G., Davis, A. F., and Hagan, 

M. P. (The Trustees of Emmanuel Coll., Boston, 
Mass.) 

Analysis of Data from Research Satellites 
AFGL-TR-78-0181 (July 1978) 

Huber, A., PANTAZIS, J. (EmmanuelColl., 
Boston, Mass.)and BESSE, A. L., ROTHWELL, 
P. L. 

Calibration of the SSJ/J Sensor on the DMSP 
Satellites 

AFGL-TR-77-0202 (September 1977) 

Hunderwadel, J. L., Morel,P. R., 
HANSER, F. A., and SELLERS, B. (Panamet., 
Inc., Waltham, Mass.) 

Design of Instrumentation Suitable for the 
Investigation of Charge Buildup Phenomena at 
Synchronous Orbit 
AFGL-TR-76-0263 (July 1976) 

Kan, J. R., and AKASOFU, S.-I. (Geophys. 
Inst., Univ. of Alaska) 

Origin of the Auroral Electric Field 
AFGL-f R-78-0018 (December 1977) 

KANAL, M. (Ctr. for Atm. Res., Univ. of Lowell) 
Effects of Non-Thermal Electrons on the Morphology 
of the Top-side Ionosphere 
AFGL-TR-77-0253 (November 1977) 

Electron Transport in an Inhomogeneous Medium 
Representative of the Terrestrial Upper Atmosphere 
AFGL-TR-78-0283 (November 1978) 

Kaufman, J. J., (Univ. of Calif., San Diego, 
Calif.) 

The Latitudinal Structure ofSolarWind Streams from 
Radio Scintillation Obseri’ations 
AFGL-TR-78-0169 (2 June 1978) 

Kaufman, P., and Do Santos, P. M. 

(Universidade Mackenzie, Sao Paulo, Brazil) 

Solar Flux and Polarization at7GHz 
AFGL-TR-76-0229(31 August 1976) 

KERSLEY, L., HAJEB-HOSSEINIEH, H., and 
Edwards, J. L. (Univ. ofColl. of Wales, Wales, 
U. K.) 

ATS-6 Observations of Ionospheric IPratonospheric 
Electron Content and Flux 
AFGL-TR-77-0107 (February 1977) 

KORFF, D. F. (Regis Coll. Res. Ctr., Weston, 
Mass.) 

Geopole Observatory Data Summary, 1 July 197i-Jl 
March 1976 

AFGL-TR-76-0197 (31 August 1976) 



Ill 


KOSTER, J. R. (Univ. of Ghana, Legon, Ghana) 
Study of the Equatorial Ionosphere 
AFGL-TR-77-0165 (30 November 1976) 

Study of the Equatorial Ionosphere: The Equatorial 
Evening Minimum in the Total Electron Content of the 
Ionosphere and its Role in Equatorial Scintillation 
AFGL-TR-78-0042 (SO November 1977) 

Phase and Amplitude Scintillation at the Equator 
AFGL-TR-78-0298 (31 October 1978) 

LANG, K. R. (Tufts Univ., Medford, Mass.) 

Fine Scale Radio Studies of the Sun 
AFGL-TR-76-0167(15July 1976) 

Fine Seale Radio Studies of the Sun 
AFGL-TR-77-0208( 15 October 1977) 

High ResolutionPolarimetryof theSunat.1.7and II.1 
Cm Wavelengths 

A FGL-TR-77-0231(19 October 1977) 

Fine Scale Radio Studies of the Sun 
AFGL-TR-78-0250 (15 October 1978) 

LANGWORTHY, B. M., (Math. Labs., Carlisle, 
Mass.) 

Some Examples of the Effects of an Auroral Trough 
Walton Ground Rangeand Azimuth Determination in 
an OTH BockscatterSystem 
A FGL-TR 77-0075 (February 1977) 

LERCHE, I. (The Univ. of Chicago, Chicago, Ill.) 

A Theoretical Investigation of Solar Wind- 
Magnetosphere Interactions and Astrophysical 
Plasma Phenomena 
AFGL-TR-76-0272 (November 1976) 

Liou, K.-N., Feddes, R. G., Stoffel, T. 

L., and AUFDER HAAR, C. (Univ. of Utah) 
Remote Sounding of Cloud Compositions from NOAA 
IV and NIMBUS VI Infrared Sounders 
AFGL-TR-77-0252 (31 October 1977) 

LUNDBAK, A., and MlKKELSEN, I. S. (Danish 
Met. Inst., Copenhagen, Denmark) 

Ionospheric Research Using Satellites 
AFGL-TR-77-0036 (30 December 1976) 

McNulty, P. J., Farrell, G. E.,Filz, R. 

C., SCHIMMERLING, W., and VOSBURGH, K. 
G. (Trustees of Emmanuel Coll,, Boston, Mass.) 
Threshold Pion Production and Multiplicity in 
Heavy-Ion Collisions 
AFGL-TR-77-0224 (12 October 1977) 

MENDILLO, M, (Boston Univ., Boston, Mass.) 
Behavior of the Ionospheric F-Region During 
Geomagnetic Storms 
AFGL-TR-78-0092GI) (March 1978) 

Tabulated Values for Average and Median Storm 
Pattern in F-Region Parameters - An Appendix to: 
Behavior of the Ionospheric F-Region During 
Geomagnetic Storms 
AFGL-TR-78-0092(III) (March 1978) 


MENDILLO, M., and BUONSANTO, M. (Boston 
Univ., Boston, Mass.) 

The Ionospheric F-Region Near 60° Magnetic 
Latitude: Monthly Mean Behairiorand Substorm 
Effects Du ring W i n ter N igh ts 
AFGL-TR-76-0233 (September 1976) 

Mendillo, M. 'Chacko, C. ., Vance, B., 

and LYNCH, F. X. (Boston Univ., Boston, Mass.) 
Numerical Simulation of Ionospheric and 
Plasmaspheric Dynamics 
AFGL-TR-78-0026 (January 1978) 

MlKKELSEN, I. S., and DAMGAARD, K. 
(Danish Met. Inst., Copenhagen, Denmark) 

Beharior of Auroral Zone Total Electron Content 
During Substorms 

AFGli-TR-76-0235 (3 September 1976) 

MlKKELSEN, I. S., and HARTMANN, H. 
(Danish Met. Inst., Copenhagen, Denmark) 
Ionospheric Research Using Satellites 
AFGL-TR-78-0043 (2 February 1978) 

Mohler, O. C., Dodson-Prince, H. W., 

and HEDEMAN, E. R. (McMath-HulbertObsv., 
The Univ. of Mich.) 

Energetic Solar Particle and Geomag-netic Storm 
Study 

AFGL-TR-78-0268 (31 October 1978) 

Pantazis, J., Huber, A., and Hagan, M. 

P. (The Trustees of Emmanuel Coll., Boston, Mass.) 
Design of Electrostatic Analyzer 
AFGL-TR 77-0120 (April 1177) 

PAPAGIANNIS, M. D., and STRAKA, R. M. 
(Boston Univ., Boston, Mass.) 

Polarization Studies at S.8 Cm of McMath Region 
UU7 of 197.1 

AFGL-TR-77-0115(May 1977) 

PAPAGIANNIS, M. D., and WEFER, F. L. 
(Boston Univ., Boston, Mass.) 

Radio Flare Studies at!, Cm 
AFGL-TR-78-0014 (January 1978) 

PARKER, L. W. (L. W. Parker, Inc., Concord, 
Mass.) 

Theory of Electron Emission Effects in Symmetric 

Probe and Spacecraft Sheaths 

AFGL—TR-76-0294 (30 September 1976) 

Potential Barriers and Asymmetric Sheaths Due to 
Differential Charging of Nonconducting Spacecraft 
AFGL-TR-78-0045( 10 January 1978) 

POMERANTZ, M. A. Bartol Res. Fdn., Franklin 
Inst., Swarthmore, Pa.) 

Study of Cosmic Radiation Near the Earth's North 
Geomagnetic Pole 

AFGL-TR-76-0201 (8 September 1976) 

RAITT, W. J. (Utah State Univ.) 

Sttidies of the Dynamics of the High Latitude 
Ionosphere 

AFGL-TR-78-0261 (26 October 1978) 



112 


REINISCH, B. W., and SMITH, S. (Univ. of 
Lowell, Lowell, Mass.) 

Geomonitor Digital Real Time Processor for 
Geophysical Data 

AFGL-TR-76-0292 (December 1976) 

ROELOF, E. C., and GOLD, R. E. (TheJohns 
Hopkins Univ., Laurel, Md.) 

Inter-Relationships of Sola rand l nterplanetary 
Plasma, Magnetic Fields and Energetic Particles 
Relei'ant to the Prediction of Solar-Terrestrial 
Disturbances 

AFGL-TR-77-0166 (29 July 1977) 

New Understanding of Energetic Particle 
Propagation in the Magnetic Fields of the Solar 
Corona and Interplanetary Medium 
AFGL-TR-78-0293 (October 1978) 

ROELOF, E. C., Gotwols, B. L.. 
Mitchell, D. G., Cronyn, W. M ., and 

SHAWHAN, S. D. (TheJohns Hopkins Univ., 
Laurel, Md.) 

Use of Interplanetary Radio Scintillation Power 
Spectra in Predicting Geomagnetic Disturbances 
AFGL-TR-77-0244 (ill October 1977) 

SAMIR, U. (TheUniv. of Mich.) 

Space Interaction Study 
AFGL-TR-77-0243 (October 1977) 

SAMIR, U., and Lake, C. I. (Univ. of Mich.) 

/w restigation of the Interaction Between the Sd-J 
Satellite and its Enrironmental Space Plasma 
AFGL-TR-78-0291 (31 October 1978) 

SELLERS, B., and HaNSER, F. A. (Panamet., 
Inc., Waltham, Mass.) 

The Relationship Between Polar Cap Riometer 
Absorption and Solar Particles 
AFGL-TR-0077 (April 1977) 

SMITHSON, R. C. (Lockheed Missiles and Space 
Co., Palo Alto, Calif.) 

Research on the Dynamics of the Solar Atmosphere 
AFGL-TR-76-0254 (31 October 1976) 

Smithson, R. C., and 1 itle, A. M. (Lockheed 

Missiles and Space Co., Palo Alte, Calif.) 

Sola r Magnetic Fields Study 
AFGL-TR-77-0249 (31 October 1977) 

SNARE, R. C. (Inst. ofGeophys. and Planet. Phys., 
Univ. of Calif., Los Angeles, Calif.) 

Fabrication and Test Report 
AFGL-TR-78-0112 (16 April 1978) 

SPIGER, R. J. (Univ. ofWash.) 

Correlation of Radar and Satellite Data to Determine 
Birkeland Current Signatures 
AFGL-TR-7 3-0129 (April 1978) 

STEIN, R. F. (Brandeis Univ., Waltham, Mass.) 
Solar Atmospheric Dynamics 
AFGL-TR-77-0108 (May 1977) 

Solar Atmospheric Dynamics 
AFGL-TR-78-0237 (September 1978) 


STRITTMATTER, P. A., and WOOLF, N. J. 

(Steward Obsv., Univ. of Ariz.) 

Image Reconstruction Using Large Astronomical 

f Pi PRPfl rU’S 

AFGL-TR-78-0167 (14 April 1978) 


STURROCK, P. A., and BARNES, C. W. (Inst, 
for Plasma Res., Stanford Univ., Stanford, Calif.) 
Force Free Magnetic Fields and Solar Actirity 
AFGL-TR-77-0023 (December 1976) 


Thomas, J. H.,Nye, A. H., and Clark, A., 

JR. (Univ. of Rochester, Rochester, N. Y.) 

Solar Magneto-Atmospheric Waves and Pennmbral 
Waves 

AFGL-TR-77-0017 (December 1976) 

TUAN, T.-F. (Univ. ofCincinnati, Cincinnati, Ohio) 
Research in Gravity Waves and Airglow Phenomena 
AFGL-TR-76-0296<23 November 1976) 


TULUNAY, Y. K. (Mid. East Tech. Univ., Ankara, 
Turkey) 

The Behavior of Ionospheric Totrl Electron C anient 
Over Ankara 

AFGL-TR-78-0300(31 December 1977) 


VeRNAZZA, J. E., AVRETT, E. H., and 
LoESER, R. (Harvard Coll. Obsv.. Cambridge, 
Mass.) 

Structure of the SolarChnnnosphere. II. The 
Underlying Photosphere and Temperature-Minimum 
Region 

AFGL-TR-76-0227 (1 July 1976) 

Vette, J. I., Chan, K. W., and Teague, 

M.J. (NASA Goddard Space Fit. Ctr., Greenbelt. 
Md.) 

Problems in Modeling the Earth's Trapped Radiation 
Environment 

AFGL-TR-78-0130 (December 1977) 


WEFER, F. L., and PAPAGIANNIS, M. D. 
(Boston Univ., Boston, Mass.) 

The Radio Spectrum of Coronal Hole I 
AFGL-TR-77-0292 (December 1977) 

WlNNINGHAM, J. D., HEIKKILA, W. J., and 
SHEPHERD, G. G. (TheUniv. of Texas at Dallas) 
Auroral Data Analysis 
AFGL-TR-77-0047( 15 February 1977) 

Auroral Data Analysis 
AFGL-TR-78-0008 (4 January 1978) 



113 


W ITHBROE, G. L. (Smithsonian Inst., Cambridge, 
Mass.) 

Models tor the SolarTransition Layer 
AFGL-TR-78-0067<22 March 1978) 

Models torSolarComnal Holes 
AFGL-TR-78-0217 <30 September 1978) 

WlTHBROE, G. L., and VERNAZZA, J. E. 
(Smithsonian Astrophys. Obsv,, Cambridge, Mass.) 

/ n vest igat ions <>/ Solar Fla res, Quiet and Art ire 
Key ions Based on EIW and Radio Observations 
AFGL-TR-76-0217 (30 September 1976) 

Artire Region Flare Rates and S.ti non Brightness 
Tew/iemtHres 

AFGL-TR-77-023G (19 October 1977) 

Young, P. S., Vesprini, R.. Holeman, 

E., and HAGAN, M. P. (The Trustees of Emmanuel 
Coll., Boston, Mass.) 

Evaluation at Generalized Geometric Factor G by l 'sc 
of Monte Carlo Method 
AFGL-TR-78-0146(June 1978) 


C alciilntion oj Generalized Geometric Factor tor 
Proton-AIpha Particle Telescope and Low-Energy 
Proton Spectrometer 
AFGL-TR-78-0137(17June 1977) 

ZlRIN, H. (Calif. Inst. ofTechnol., Pasadena,Calif.) 
Cooperative Studies of Solar Activity and 
Chromospheric Structure 
AFGL-TR-77-0105 (7 December 1976) 

ZlRKER, J. B. (Inst, for Astron., Univ. of Hawaii) 
Observational Research on Solar Coronal Waves 
AFGL-TR-77-0026(31 December 1976) 

ZUKAUSKIS, J. W., HURWITCH, B. B 
Murray, P. D., and Vaillancourt, R. C. 

(Spacetac, Inc., Bedford, Mass.) 

Development, Fabrication and Service of lnstmments 
tor Use in Electrical Structures and Related Space 
Flight Measurements 
AFGL-TR-77-0056 (28 February 1977) 


v- 










V METEOROLOGY DIVISION 





I 

< 

4 

J 

rt 

j 

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A 



The Air Force of the 1980’s, like its 
jiredecessors, will continue to feel the im¬ 
pact of meteorological phenomena. It is true 
that some operations will be less affected by 
weather elements. But other, and newer, 
operations now anticipated will involve 
newer and more complex systems that are 
weather-dependent. So the search for 
better methods of observing and predicting 
meteorological conditions has continued to 
be the principal effort of the Meteorology 
Division. 

During the past 80 months, the program 
of the Meteorology Division has included 
the development and testing of automated 
techniques of observing, disseminating, dis¬ 
playing, and predicting critical airfield 
weather elements, methods for processing 
and displaying the voluminous imagery data 
received from meteorological satellites, 
techniques for the processing and display of 
radar data used in detecting significant fea¬ 
tures of storms and predicting their motion 
and severity, instrumentation and analyt¬ 
ical methods for determining the micro¬ 
physical characteristics of clouds and pre¬ 
cipitation during reentry of hypersonic 
ballistic missiles, methods of modeling at¬ 
mospheric circulations and increasing the 
efficiency and accuracy of numerical 
weather prediction, climatological tech¬ 
niques for use in the design and operation of 
a variety of Air Force systems, and ways of 
dissipating warm fog at air bases and 
creating holes in super-cooled stratus 
clouds. 

Much of the meteorological instrumenta¬ 
tion and related software has been 
developed for use in in-house research in¬ 
vestigations, but other instrumental ap- 



n« 


proaehes have been examined to determine 
their feasibility for eventual use in systems 
to be operated by the Air Weather Service. 
Equipment has been developed and tested 
not only at Hanscom AFB but also at two 
held sites in Massachusetts operated by the 
Meteorology Division — the Weather Ra¬ 
dar Facility at Sudbury and the Weather 
Test Facility at Otis AFB. Aircraft equip¬ 
ment has been tested on a C-130E aircraft 
operated by Air Force personnel, and on a 
leased Lear,jet operated by contractor per¬ 
sonnel. 

MESOSCALE OBSERVING AND 
FORECASTING 

A fully automated system to observe, pre¬ 
dict. disseminate, and display airfield 
weather could reduce the workload of 
weather observers and forecasters. Devel¬ 
opment of such a system has been the pri¬ 
mary program of the Mesoscale Forecasting 
Branch during this reporting period. Other 
objectives of the mesoscale R&D program 
were the development of objective and auto¬ 
mated weather prediction schemes for short 
range forecasting and the use of the very 
high resolution data available from sensors 
on board the Defense Meteorological Satel¬ 
lite Program satellites. 

Automated Weather System Develop¬ 
ment: Requirements for weather support in 
the Air Force are variable and dependent on 
the mission to be satisfied. Also, significant 
economies can be realized by utilizing, to the 
fullest extent possible, weather sensors in 
the current inventory which can be auto¬ 
mated. Therefore, the whole concept of the 
Modular Automated Weather System 
(MAWS) has been built around a modular 
design to ensure flexibility. Studies of sen¬ 
sor automation have addressed the full 
range of components of the operational, 
non-tactical inventory as well as the devel¬ 
opment of new instrumentation and/or 
specification techniques in those areas 
where existing sensors are either inade¬ 
quate or not available. Microprocessing 
technology has reached levels of reliability. 


miniaturization and cost effectiveness 
which enable us to proceed with a design 
methodology that presumes on-site (or 
within-sensor package) processing of indi¬ 
vidual sensor output, suitably averaged and 
prepared for transmission, on request, to a 
central processing site. 

Among inventory sensors, the AN/GMQ- 
20 wind set. the AN/GMQ-11 trans- 
missometer. and the AN/GMQ-13 Rotating 
Beam Ceilometer (RBC) were found to be 
suitable for automation. The AN/TMQ-11 
temperature/dewpoint set and the ML-331/ 
TM barometer were found to be unac¬ 
ceptable. Automation of the transmis- 
someter required replacement of vacuum 
tubes with solid state amplifiers. Our 
evaluation of the solid state amplifier modi¬ 
fication kit resulted in an upgrading of its 
operational transmissometers. The wind set 
was automated by incorporating com¬ 
mercially available synehro-to-digital con¬ 
verters into a microprocessor-based inter¬ 
face module. The rotating beam ceilometers 
presented the most complex automation 
problems. Modifications to solid-state elec¬ 
tronics solved most of the hardware prob¬ 
lems. The software analyzes the sequence of 
five observations gathered during a one- 
minute duration to yield the estimated cloud 
base height over the observing site. 

More accurate and reliable surface 
weather instruments are being sought to 
replace present instruments which have 
been used for a long time and to measure 
weather elements which now require a hu¬ 
man observer. Several observing tech¬ 
niques and instruments having good poten¬ 
tial for use in fully automated systems are 
being developed and evaluated at AFGL 
and at the Meteorology Division’s Weather 
Test Facility at Otis AFB. Massachusetts. 
The Weather Test Facility was established 
in 1975 to permit rigorous, long-term evalu¬ 
ation of new and improved instruments at a 
location which frequently has cloudiness, 
reduced visibility, and many forms of pre¬ 
cipitation. 



Laser devices to sense weather elements 
such as visibility, cloud base height, and 
low-level wind profiles are being developed 
and tested by both AFGL and contractor 
personnel. A lidar (light detection and rang¬ 
ing) ceilometer being considered for auto¬ 
mated ceilometrv measurements uses an 
erbium-doped glass laser as its transmitting 
source. In cooperation with NOAA’s Wave 
Propagation Laboratory, an experimental 
helium-neon laser device to discriminate 
among various types of hydrometeors and 
obstructions to vision has been field tested 
at the Weather Test Facility. Some objec¬ 
tives have already been satisfied. However, 
the Equipment Development Laboratory of 
the National Weather Service is now ex¬ 
tensively redesigning the device to enable 
the full required capability to be achieved. 

When airfield visibility conditions are 
close to the landing minima, the problem of 
measuring visibility in the approach zone 
becomes critical. The ability of a pilot to 
perceive the runway and its environs as he 
approaches the point on the glideslope 
known as “decision height" is often less than 
that of an observer viewing horizontally 
along the runway. Devices to provide the 
pilot with better measures of his visual 
range at decision height have been pursued 
along two lines at AFGL. An experimental 
lidar system employing a frequency- 
doubled ruby laser was contracted for in 
1975. Its novel design concept offered the 
potential of solving the multiple scattering 
problem which plagued earlier designs, of 
having sufficient penetration capability in 
low visibility conditions, and of being eye- 
safe. The design also involved a high tech¬ 
nical risk; to date, the instrument has not 
performed satisfactorily during contractor 
tests and at AFGL. An alternative, less 
technically risky solution to the problem of 
determining slant visual range has been 
tested at the Weather Test Facility and 
found to yield highly accurate results. It 
takes point measurements of visibility at 
the 10-. 50-. and 100-foot levels of tt tower 
located a safe distance to the side of the 


runway touchdown point and translates 
them into an estimate of visual range in the 
landing zone. Studies at the Weather Test 
Facility have confirmed that widespread 
and dense fog is largely homogeneous hori¬ 
zontally. while it is highly variable vertic¬ 
ally. The effectiveness of this approach has 
been demonstrated during several episodes 
of dense fog. The estimation error of this 
technique is only one-third the error of a 
commonly used ground-based technique. 

A low-risk approach to present weather 
determination is being pursued using a de¬ 
cision-tree method and an array of commer¬ 
cially available weather sensors which had 
been individually subjected to rigorous 
evaluation during tests at AFGL and else¬ 
where. Ground-based and tower-mounted 
temperature-dewpoint sets, wind sensors, 
forward-scatter and backscatter meters, a 
transmissometer. a nephelometer, and a 
tipping-bucket rain gauge are used in this 
method. An identification rate of 90 percent 
has been achieved thus far in tests con¬ 
ducted in non-winter situations. 

Wind sensors must be deployed in remote 
and sometimes harsh weather locations. 
This requirement has led to an evaluation of 
several commercially available sensors, 
some employing novel sensing principles. 
These include sensitive, yet rugged, cup- 
vane and prop-vane models; devices based 



MAWS Wind System designed for the AFWL 
TRESTLE Program Office and installed at 
Kirtland AP B, New Mexico. 








118 


on a vortex shedding principle: and differ¬ 
ential pressure probes with no moving 
parts, suitable for cold region deployment. 
Intercomparison and reliability tests are 
underway at the Weather Test Facility. 

A prototype Modular Automated 
Weather System (MAWS) being evaluated 
at Scott AFB. Illinois, since January 1977 
uses more sensors than any system antici¬ 
pated to support fixed base operations in 
order to determine the number and spacing 
of airfield observing sites and frequency of 
observations required in an actual system. 
At each observing site, wind speed and di¬ 
rection, temperature, dewpoint and sensor 
equivalent visibility are measured contin¬ 
uously. Three surface observing sites are 
located adjacent to Runway 1.4/41 close to 
existing operational weather instruments 
located near the end points and mid-point of 
the runway. Observations are also gathered 
at the 2f> and 40-meter levels of an instru¬ 
mented tower offset (500 meters from the 
touchdown end of Runway 14. 

The same type of microprocessor is used 
in the central supervisory station and the 
weather measurement sites. It has a proc¬ 
essing unit, read-write and programmable 
memory units, and suitable control logic. 
The logic programmed into the micro¬ 
processors for the remote observing sites 
reads voltages from each sensor several 
times each minute, converts the data to 
appropriate meteorological units, averages 
the data and prepares the data for trans¬ 
mission to the supervisory microprocessor. 

Fresh observations, updated each 
minute, are displayed on alpha-numeric 
plasma display devices in the Scott AFB 
weather station and AWS Headquarters, 
The display has four pages of output which 
are individually displayed each minute. 
These include the latest observations, com¬ 
parative data from 5, 10, 15 and 40 minutes 
earlier, “metwatch” parameters pertinent 
to alerts or warnings when critical thresh¬ 
olds are exceeded, and automated prob¬ 
ability forecasts of runway visual range and 
cloud base height for prediction intervals as 


long as three hours. The system has been 
continuously evaluated, redesigned and 
modified. 

At the request of the TRESTLE Pro¬ 
gram Office at Air Force Weapons Labora¬ 
tory. Kirtland AFB. New Mexico, a micro¬ 
processor-based wind warning system has 
been designed, fabricated and installed at 
the TRESTLE site in New Mexico by 
AFGL engineers and technicians. Minute- 
by-minute updates of wind conditions ad¬ 
jacent to the TRESTLE platform will be 
constantly available to the Test Director to 
ensure safe and efficient test operations. 
After wind data at the test site are archived 
for several months prior to actual opera¬ 
tions. short-range wind prediction algo¬ 
rithms, adjusted for conditions at the top¬ 
ographically complex site, will be developed 
for use by Air Weather Service forecasters 
tasked to support test operations. 

Short Range Forecasting: Rapidly 
changing weather events, superimposed on 
complex weather support requirements, in 
a hostile tactical environment place diffi¬ 
cult, even overwhelming, demands on the 
Air Force weather forcaster. AFGL 
mesoscale forecastir g research is aimed at 
developing objective procedures to aid the 
field forecaster responsible for forecasting 
critical weather elements for time periods 
up to six hours. Since the observations 
available to the forecaster in a wartime 
situation can range from minimal (he knows 
conditions only where he is located) to a full 
data set from all available sources, tech¬ 
niques are being developed which can 
handle variable initial conditions. Single¬ 
station, single-element statistically based 
models which yield exceedance probability 
predictions for periods out to three hours 
have been developed for aviation-critical 
elements, such as runway visual range, 
cloud base height and slant visual range. 
Extension of these models, which rely on 
ground-based measurements, to include 
spatial and temporal variations of a par¬ 
ticular predictand. is presently under in¬ 
vestigation. 





119 


( 

I 



A potentially powerful source of tactical 
weather information is the meteorological 
satellite. Geosynchronous satellites provide 
frequent views of a wide area which can be 
used effectively in sensible weather predic¬ 
tion models. The meteorological satellite 
program at AFGL has, for the past two 
years, turned to developing automated data 
extraction, analysis, interpretation and 
short-range prediction techniques which 
rely heavily on visible and infrared geo¬ 
synchronous imagery. 

With a few exceptions, satellite imagery 
has previously been applied by subjective 
methods. The development of real-time 
methods of introducing satellite data into 
objective short-range forecasts is the sub- 



Antenna for Real Time GOES Data. 


ject of a four-pronged program. The first 
approach is a straight-forward statistical 
one. It involves using digital imagery to 
define and predict clouds and precipitation. 
In concept, the visual and infrared imagery 
for an appropriate sector around a selected 
terminal or target is extracted from the 


satellite’s transmission stream. These data, 
in some cases combined with conventional 
data, are processed by appropriate statis¬ 
tical operators to generate a probability 
forecast. Depending on the operation which 
the forecast is supporting, it might be ex¬ 
pressed as the probability that an event will 
occur in the next two. three or four hours or 
the probability of the intensity or duration 
of the event. The forecast is delivered to the 
meteorologist or the operationaw decision 
maker, or even entered into the computer’s 
memory for direct utilization in a larger 
matrix of information bearing on an opera¬ 
tion decision. 

A second approach makes use of an inter¬ 
active computer system to search for pre¬ 
dictors by relating features and changes in 
the imagery with the developments in 
various circulation fields, including those 
based on winds derived from cloud dis¬ 
placements between geosynchronous satel¬ 
lite frames. A third approach is to compare 
computer-generated descriptions of the 
current “weather state” made from satellite 
data with weather forecasts based on 
numerical methods. The objective is to 
develop guidelines as to when and where it 
is best to rely either on the computer cal¬ 
culation of weather from satellite data or the 
numerically basedsforecast. The latter two 
approaches were recently initiated under 
university contracts. 

Still another short-range forecasting 
method that can be effective is extrapola¬ 
tion. Techniques developed for extrapolat¬ 
ing radar echoes, noted in the last AFGL 
Report on Research, can be used to forecast 
the motion of satellite-observed clouds. Two 
problems must be resolved for the tech¬ 
nique to be useful. The first is that the 
clouds must be located accurately because 
the motion can be no more accurate than the 
initial and final positions. This navigational 
problem, which is critical to the other as¬ 
pects of the short-range forecasting work as 
well, has been solved using the Man- 
computer Interactive Data Access System 
(McIDAS) to obtain the optimum 



120 


adjustment of the transform between image 
and earth coordinates. 

The second and larger problem is obtain¬ 
ing the motion vectors automatically. Cur¬ 
rently we are testing four techniques for 
cloud displacement to see if there is any 
clear superiority among them. Two of the 
techniques involve re-arranging the cloud 
elements to form groups of smoothed syn¬ 
thetic clouds. This is called clustering. A 
third method uses the cross correlation be¬ 
tween the fast Fourier transforms of the 
initial and final data field. The fourth 
method is a binary form of the cross¬ 
covariance approach. The data are reduced 
to a single bit per pixel which, with the use 
of some fast FORTRAN masking instruc¬ 
tions. speeds up the computation of vectors. 
These tests are now under way. 

Satellite Specification Studies: In order 
to use all the fine mode data generated by 
Defense Meteorological Satellite Program 
(I)MSP) satellite sensors for the detection of 
small-scale cloud features throughout the 
globe, human interpretation of satellite 
images must be replaced by automated 
techniques and these techniques must 
necessarily be efficient. Two approaches 
have been developed to improve the utiliz¬ 
ation of fine mode satellite imagery. The 
first approach reduces the number of levels 
of brightness or “gray shades” needed to 
display the image from 64 levels (6 bits), 
which are currently used for DMSP visible 
images, down to two levels (1 bit). In a test, 
an original DMSP image with 64 gray 
shades was photographed from an AFGL 
McIDAS display. The bit reduction algo¬ 
rithm was applied and the resulting image 
with only two gray shades was very similar 
in appearance, since not only was the solid 
central cloud mass retained but also small or 
darker cloud elements. The commonly 
applied process is to truncate the image so 
that all the darker shades are made black 
and all the lighter shades are made white. 
The bit reduction algorithm picture looked 
much better because the algorithm replaced 
areas having intermediate gray shades with 


a very fine checkerboard of white and black 
cells, rather than arbitrarily making them 



Top, DMSP visible imagery with standard 64 
shades of gray: middle, same imagery after 
applying AFGL bit reduction algorithm yield¬ 
ing 2 gray shades; bottom, same imagery as 
top after applying truncation algorithm yield¬ 
ing 2 gray shades. 





121 


all white or all black, and the human eye 
interprets the checkerboard as an inter¬ 
mediate gray shade. 

A second approach employs a spectral 
technique in which the original image is 
transformed by a two-dimensional fast 
Fourier transform and the resulting Four¬ 
ier coefficients are used to classify the con¬ 
tents of the image. The Fourier transform 
reflects the spatial distribution of bright¬ 
ness in the image and estimates the sizes 
and organization of clouds in the image 
better than the first-order statistics. The 
strength of the classifier will be tested using 
imagery samples from various climates and 
cloud types. 

Like the fine mode imagery data, new 
multispectral observations greatly increase 
the rate at which data are to be sampled, 
which leads to problems in data storage on 
the satellite, transmission to the ground, 
and information extraction on the ground. 
DMSP satellites may increase the number 
of imagery channels to six or more by 1982. 
Although these new forms of weather satel¬ 
lite data require fast and accurate techni¬ 
ques for information extraction, current 
operational processors for multispectral 
imagery data are limited. Two approaches 
to improved cloud identification based on 
multispectral analysis of satellite data have 
been examined under contract. The first 
approach used multispectral channels from 
infrared sounders. Cloud identification 
using sounder data requires extensive cal¬ 
culations using a spectral infrared radiative 
transfer model. It treats: 1) the inhomo¬ 
geneity of the cloudy atmosphere by divid¬ 
ing the cloud layer into sublayers. 2) gas¬ 
eous absorption in scattering cloud layers, 
and 3) the wavelength dependence of radia¬ 
tive transfer. The method works best when 
both short-wave and long-wave infrared 
sounder channels are used in combination 
because short-wave channels are more sen¬ 
sitive to overcast cirrus or middle level 
clouds. 

A second study considered microwave 
and near-infrared channels, candidates for 


future DMSP satellites, along with existing 
infrared and visible channels as estimators 
of cloud features. Models of radiative trans¬ 
fer in cloudy atmospheres were used to 
estimate cloud radiance observables from 
satellites for varying cloud altitudes, thick¬ 
nesses. mass densities, rainfall rates, and 
for various underlying surfaces. Separate 
models were generated for microwave ob¬ 
servations only and for microwave and 
other spectral observations. Four different 
inverse models were developed and given 
extensive tests. These results were used to 
classify continuous cloud variables, such as 
cloud thickness. Discrete categories, such 
as ice or water clouds, snow surface or bare 
ground, etc., were discriminated by a 
Friedman Tree classification, which deter¬ 
mines critical thresholds for decision-tree 
algorithms. 

Tropical Cyclone Prediction: Fore¬ 
casting of tropical cyclone movement was 
approached from two directions. One ap¬ 
proach was to seek keys to storm translation 
in the distribution of cloudiness within a 
radius of several thousand miles from the 
storm center. The second approach was to 
test whether the addition of winds derived 
from cloud displacements to the initial wind 
field would improve a barotropic numerical 
forecast. 

The technique used to search for large- 
scale characteristics of the cloud field as 
indicators of storm motion was to construct 
composites of satellite visible images that 
contained tropical storms of similar char¬ 
acteristics. The composite technique rein¬ 
forces consistent features of the large-scale 
cloud distribution and mutes the random 
details. A second series of tests, incorporat¬ 
ing infrared imagery in addition to the visi¬ 
ble imagery, did not improve predictions. 

Tropical storms develop and spend most 
of their lifetime over data-sparse ocean 
areas at low latitudes for which the equation 
used to calculate the wind fields from pres¬ 
sure measurements is less reliable than at 
high latitudes. Thus, application of numer¬ 
ical weather prediction techniques to hurri- 



122 


cane and typhoon forecasting has been 
limited. However, when vertically aver¬ 
aged winds from ten levels extending from 
the surface to lfi km were used in a model 
called SANBAR, hurricane tracks were 
predicted reasonably well. An AFGL con¬ 
tractor studied cloud motion vectors de¬ 
duced from geosynchronous satellite images 
to determine how well they approximated 
the vertically averaged wind. Predictions 
were improved when three or more cloud 
motion vectors can be deduced within the 
influence region of the storm. 

MAN-COMPUTER INTERACTIVE 
DATA ACCESS SYSTEM 

The original Man-computer Interactive 
Data Access System (McIDAS) was de¬ 
signed and developed at the Space Science 
and Engineering Center at the University 
of Wisconsin as a means of interactively 
processing and displaying meteorological 
satellite images. A duplicate system was 
installed at AFGL in 1975. This basic 
system had no real-time data acquisition 
capability, but was still a useful tool for 
weather research. During the period of this 
report, the system was expanded twice. In 
the winter of 197(5-1977, a 24-foot parabolic 
antenna was installed at AFGL with step- 
track control to acquire a direct (stretched) 
transmission from the SMS/GOES series of 
geosynchronous satellites. A waveguide 
nsr bed receiver was assembled and, with 
its associated bit synchro iizeriS was in¬ 
stalled. 

Following this addition to the McIDAS 
system, software developed by the Uni¬ 
versity of W isconsin was added to give the 
Meteorology Division full access to live data 
from the Eastern and Western geosyn¬ 
chronous satellites. These data were used in 
a number of research projects within the 
Division. AFGL software additions pro¬ 
vided a capability to compute and display 
Environmental Severity Index values, 
employed by the Division in its support of 
the Space and Missile Systems Organiza¬ 
tions (SAMSO) Advanced Ballistic Reentry 


System (ABRES) program, from a pair of 
visible and infrared images. With McIDAS, 
the Division has been able to display navi¬ 
gated images, obtain statistical data about a 
designated point, compute winds from cloud 
motion, enhance images in black and white 
or color, and read texperatures from an 
infrared image to provide data for support 
of aircraft operations, for decision-making 
in the ABRES program, and for improving 
forecasting efforts. 

As the power and applicability of Mc¬ 
IDAS became apparent, a second system 
modification was made by the University of 
Wisconsin in December 1977. This modifi¬ 
cation added a second terminal, graphics 
capability, and ability to acquire surface and 
upper air data with the system. 

Following installation of the hardware, 
the software was modified by the Meteorol¬ 
ogy Division to work in the AFGL configu¬ 
ration. and the full capability for analysis 
and display of conventional data was on line 
in April 1978. 

Command units for the antenna provide 
push-button selection of either the Eastern 
or Western satellite as a data source. In 
addition, there is the newly incorporated 
capability to generate and display maps of 
meteorological data fields, such as stream¬ 
lines. isobars, heights of pressure surfaces, 
cloud amounts and present weather. These 
features have made McIDAS a more valu¬ 
able facility in support of research and de¬ 
velopment in the Meteorology Division. 

WEATHER RADAR TECHNIQUES 

The Meteorology Division continued its 
investigation of atmospheric structure by 
radar during this reporting period, particu¬ 
larly in two areas where operations are 
based on weather radar information. One is 
developing improved weather radar in¬ 
strumentation and data processing tech¬ 
niques which will enable prediction of the 
motion and development of significant 
storms reliably, and quickly enough to be 
useful. The other is accurately measuring 




123 


and predicting precipitated water content 
encountered along the reentry trajectory of 
SAMSO test vehicles. This work is part of 
an overall effort to define the size distribu¬ 
tion. phase, and concentration of hydro¬ 
meteors affecting nose cone erosion of these 
vehicles at supersonic speeds. This work is 
described more completely in the Weather 
Erosion section of this chapter. 

Both widespread and convective pre¬ 
cipitation systems are studied at the AFGL 
Weather Radar Facility at Sudbury. Massa¬ 
chusetts. Scientists use an experimental C- 
band Doppler radar with state-of-the-art 
processing and color display equipment, an 
X-band weather surveillance radar, and 
various auxiliary meteorological sensors. 
Techniques, instrumentation, and software 
for measuring, processing, displaying, and 
automatically interpreting ground-based 
weather information are developed. During 
recent spring storm seasons, data on severe 
convective storms have also been acquired 
in central Oklahoma at the National Severe 
Storms Laboratory, in a joint agency coop¬ 
erative program for the operational evalu¬ 
ation of Doppler weather radar technology. 
The Weather Erosion Program has used 
high-power ultra-sensitive radars at the 
Kwajalein Missile Range at Roi Namur. 
Marshall Islands, together with advanced 
processing and display equipment tailored 
to the specialized needs of these programs. 

Storm Diagnosis: Doppler radar has 
significantly improved our ability to identify 
severe thunderstorms, by allowing the di¬ 
rect measurement of the wind structure, as 
well as precipitation intensity. For several 
years, meteorologists working with 
Doppler radar have qualitatively recog¬ 
nized the close association of severe thun¬ 
derstorms with the mesocyclone, which is a 
vortex with a diameter of 1 to 10 km. ro¬ 
tating at speeds of up to 50 meters per 
second, located within a small region of 
some thunderstorms. The mesocyclone is an 
important feature because it is a very re¬ 
liable precursor, while it is still aloft, of tor¬ 


nadoes or other types of destructive 
weather occurring minutes later at the 
ground. This behavior pattern of meso- 
cyclones provides the basis for much better 
severe storm warnings, but quantitative 
prediction of the time, place, and intensity 
of storm damage at the ground is not yet 
possible. 


DIGITAL DATA - 20 MAY 1977 



The development of maximum shear across 
the mesocyclones which produced the Del City 
(solid line) and Arcadia (dashed line) tor¬ 
nadoes. The duration of the two tornadoes at 
the ground is indicated by the heavy solid lines 
along the base of the diagram. Large values of 
shear are very closely associated with the 
appearance of tornadoes at the ground. 

During the operational evaluation of 
Doppler technology in Oklahoma, several 
mesocyclones and their accompanying 
tornadoes were observed and recorded. The 
development of these mesocyclones was 
studied to enable prediction of the time 
when the tornadoes would touch the 
ground. The maximum shear, or change of 
wind velocity across the mesocyclone, was 
very well correlated with tornado occur¬ 
rence. The height of maximum wind speed 
and of minimum diameter in the meso¬ 
cyclone descended by 3 to 5 km prior to a 
tornado. Another parameter strongly asso¬ 
ciated with tornado touchdown is the min¬ 
imum height of zero divergence. This is the 
height at which all wind motion contributes 
to rotation, with virtually no air entering or 
leaving the vortex. This pilot study will be 
expanded to many other cases in search of a 
reliable way to predict the time of surface 
damage. 



124 


Heavy snow disrupts activity by tem¬ 
porarily closing runways (and roads) and by 
reducing visibility. The accuracy limits on 
estimation of snowfall rates by meas¬ 
urement of radar reflectivity were studied. 
The great variability in snow crystal type, 
snowflake size, and especially wetness of 
the snow when it falls through temper¬ 
atures slightly above 0 degrees C make 
snowfall rate considerably more difficult to 
estimate than rainfall rate. 

Skilled observers made a total of 187 
measurements of snowfall in six coastal 
snowstorms during January through March 
of 1978. Corresponding values of radar re¬ 
flectivity were averaged during each of the 
measurement periods, for each location. 
The data for each storm covered a wide 
range of snowfall rates and radar reflec¬ 
tivities. A correlation of radar reflectivity 
and snowfall rate indicated that radar is 
useful for remote estimation of snowfall 
rate, provided that surface reports assure 
that the snow is dry. 

When hurricane Belle invaded southern 
New England in August 197(5, the weather 
radar was used to study some of its features. 
Landfall had caused disorganization of the 
eye of the storm before it came within range 
of the radar, but several of the hurricane 
rain bands passed over the radar site and 
were observed with suitabie resolution. 
Curvature of the wind field in the innermost 
rain band was evident, consistent with a 
model with a small radial flow toward the 
hurricane center combined with a mainly 
tangential flow around the center. The 
measurements also showed wind speeds 
decreasing with increasing distance over 
land, and the existence of a small-scale wave 
pattern superimposed on the large-scale 
wind field. These observations are not only 
intriguing, they are also the first reported 
measurements by Doppler radar of the wind 
structure in a hurricane. 

Weather Radar Instrumentation: In 
recent years, large-scale radar data proc¬ 
essing systems have been developed to 
generate weather information in real time. 


While these systems offer considerable 
promise, automatic system calibration and 
ground clutter suppression devices are 
needed to make them more effective. 
Laboratory and contractor scientists have 
recently developed instrumentation to 
overcome these limitations. 

Both Doppler and conventional radars 
can be calibrated with a newly developed 
test set which provides continuous pulse to 
pulse calibrations of the transmitting and 
receiving equipment. The peak power in the 
transmitted pulse is measured by com¬ 
paring it to a known power level. The 
measured power level of the pulse is repre¬ 
sented by the coding of a pulse train of con¬ 
stant amplitude. The amplitude of this pulse 
train is used to calibrate the entire receiving 
system, and the decoded value of the 
transmitter pulse power provides the infor¬ 
mation needed so that the transmitter can 
be calibrated. This approach may provide an 
automated means of standardizing the net¬ 
work of radars operated by the Air Weather 
Service and the National Weather Service. 

Interference from ground target returns 
is a problem for Doppler as well as con¬ 
ventional radars. Doppler weather radar 
spectral moment processors, such as 
AKGL's Pulse Pair Processor, are par¬ 
ticularly sensitive to ground clutter because 
these processors use the entire unam¬ 
biguous velocity range of the radar, which 
includes both weather phenomena and 
ground clutter. A filter has been developed 
which cancels ground echoes at all ranges. 
Tests of the filter indicate that it rejects 
99.99 percent of the signals from objects 
moving less than 0.32 meter per second, 
while signals from weather targets with 
velocities greater than 1 meter per second 
are passed undiminished. Ripple introduced 
by filtering is less than 1 dB over the un¬ 
attenuated portion of the velocity band. 
This clutter filter greatly improves the 
accuracy of Doppler spectrum mean and 
width estimates. 



125 


Weather Radar Data Automation: Al¬ 
though the trained radar meteorologists in 
the Laboratory have used Doppler color 
displays to demonstrate the superior 
capabilities of Doppler radar, operational 
Air Weather Service stations do not have 
such highly trained observers to interpret 
complete weather radar data. To give the 
benefits of this new technology to operating 



ETSE Attribute Listing. Significant attri¬ 
butes of the detected cells are summarized for 
easy assimilation by the forecaster. The cells 
are labeled for cross reference with the color 
display tracks. 

organizations without requiring increased 
training of potential users, a data process¬ 
ing system has been designed. This system, 
called the Echo Track and Significance 
Estimator, or ETSE, provides a summary 
list of radar-derived attributes of each 
storm cell as well as the cell’s past storm 
track and forecast track. Newer develop¬ 
ments in Doppler weather radar meteor¬ 
ology can be incorporated into the analysis 
and forecasting by changing the pro¬ 
gramming. 

Algorithms are developed and encoded on 
the ETSE to test realtime methods of data 
analysis. A precipitation area is considered 
significant if its radar reflectivity and size 
each exceed certain predetermined values. 
Attributes computed for each precipitation 
area include area centroid location, reflec¬ 


tivity-weighted area, maximum velocity, 
maximum spectral width, and speed and di¬ 
rection of cell movement. The computer also 
uses consecutive radar scans to generate a 
color display of present outline, past track, 
extrapolated position and the attribute list¬ 
ing number of each echo area together with 
a listing of observation and forecast times. 
A map of the local area is an overlay for the 
meteorological information. 

Operational Test of Doppler Tech¬ 
nology: The National Weather Service, Air 
Weather Service, National Severe Storms 
Laboratory, Air Force Geophysics 
Laboratory, and the Federal Aviation 
Administration have joined in a program 
known as the Joint Doppler Operational 
Project, to evaluate Doppler weather radar 
for operational applications and to develop 
specifications for an advanced system which 
all these agencies can use. The system will 
replace the aging FPS-77 and WSR-57 
systems in the national weather radar 
network. However, the final system should 
not only make the routine observations 
made in the present national network but 
also be able to measure the internal struc¬ 
ture of severe thunderstorms to provide 
warnings of tornado-like winds, large hail, 
and dangerous turbulence. 

During the spring months of 1977 and 
1978, Doppler radar technology was tested 
in operation, using the experimental 
Doppler radar of NSSL, supplemented by 
data processing and display equipment oi 
AFGL and NWS. Tornadoes and other 
severe convective storms were identified by 
the mesocyelones they contained. A meso- 
cvclone has the unique velocity signature on 
the display of a velocity maximum adjacent 
to a velocity minimum at the same range, 
persisting for at least several minutes and 
extending several km in height. High vel¬ 
ocities at ground level indicated damaging 
windstorms. When they recognized severe 
weather, project personnel transmitted ad¬ 
visories to affected civilian and military 
weather forecast offices located throughout 




12t> 


Oklahoma and in adjacent areas of Texas, 
Kansas, and Arkansas. 

The warnings issued by the Joint Doppler 
Operational Project were compared with 
warnings issued by the Oklahoma City 
Weather Service Forecasting Office, which 
did not have the benefit of Doppler informa¬ 
tion. Doppler technology achieved a prob¬ 
ability of detection slightly greater than 
conventional methods, but had less than half 
its false alarm rate. Another significant 
advantage of Doppler was its lead time, 
which averaged 21 minutes, and greatly 
exceeded this value for the most destructive 
and largest tornadoes. Conventional 
methods, on the other hand, rely on human 
spotters, who do not detect a tornado until it 
descends below the cloud base. Conven¬ 
tional techniques, therefore, required al¬ 
most two minutes after the tornado touched 
down before a warning was issued. 

During the second year of testing, one 
large tornado was identified as a life- 
threatening storm nearly 40 minutes before 
it touched down. The advisories allowed all 
residents of the threatened area plenty of 
time to get into their storm cellars or drive 
away to a safer location. The Echo Track 
and Significance Estimator was also put into 
operation during the second year. During an 
outbreak of severe storms on April 5, 1978, 
this automated system showed a significant 
shift in the direction of motion of a storm 
which had developed an intense meso- 
cyclone. indicative of a tornado. This change 
was put into the advisory, resulting in a 
changed warning which alerted residents 
who had previously thought the danger 
would pass well to their north. The tornado 
struck along the revised track, but the 
residents had taken action to escape the 
tornado. 

The tests also demonstrated a capability 
for recognizing low '.titude wind shear 
which could be dange •ou s to aircraft landing 
or taking off. On one occasion, a shallow 
gust front was generated by very ordinary 
thunderstorms embedded within wide¬ 
spread precipitation. Descent through this 


gust front, which was completely obscured 
by clouds and precipitation, would have 
been extremely dangerous for an airplane 
trying to land. Below an altitude of 1 km. the 
head winds would have shifted to tail winds 
at an accelerating rate. The loss in airspeed 
would have been 50 knots by the time the 
aircraft reached the head of the gust front at 
an altitude of 200 to 300 meters. Remote 
sensing of such dangerous wind shear by 
Doppler radar can provide the warning 
needed to aircraft. 


PUMPKIN CENTER - MARLOW STORM TRAO 


Display of storm tracks for April 5. 1978, 
superimposed on county map of Oklahoma. 

Shaded area surrounding “1” marks position at 
2054 CST of storm which produced the Marlow 
tornado. Past positions, extending westward, 
are coded in color on the original display and 
matched to color-coded times listed along the 
right. 

CLOUD PHYSICS 

The cloud physics program is directed 
into five areas. One of these areas, measure¬ 
ment and forecasting of cloud, rain and snow 
types and particle size distributions for 
weather erosion testing of reentry vehicles, 
absorbed almost all of the resources of the 
cloud physics effort from 1972 through 1977. 
The other four area of cloud physics are: 
development of airborne cloud physics in¬ 
strumentation: determination of character¬ 
istics of high altitude cirrus cloud particles: 
investigations of cloud, rain and snow types, 
associated particle size distributions and 




127 


ice/water contents in large-scale cloud 
systems as storms develop and cross the 
United States: and development of statis¬ 
tics of water content, cloud, rain and snow 
types with their particle size distributions 
for Air Force applications. Two AFGL- 
instrumented cloud physics aircraft, an MC- 
130E and a Learjet :l(i, were used to obtain 
data for real-time mission control decisions, 
for post flight analysis, and for research 
studies. 

The contributions of the cloud physics 
program to weather erosion testing are 
presented in the next part of this chapter. 

Information on the microphysics of 
clouds, particularly in large-scale cloud sys¬ 


tems, is inadequate. Data on particle types, 
size distribution, and ice versus liquid water 
content are rare and localized, and most 
have been taken in unusual storms. A sys¬ 
tematic study of the microphysics of large- 
scale cloud systems was begun in October 
1977 to acquire an adequate data base of 
cloud physics information for Air Force 
development, test, and operational needs. 

An analysis of Air Force needs has shown 
a need for instruments to measure the mass 
of high-altitude cirrus cloud particles and 
for instruments to measure ice/water con¬ 
tent in the melting layer where large snow¬ 
flakes melt into raindrops while falling 
through the atmosphere. 



One of the better examples of stellar crystals 
recorded by the laser shadowgraph. Pattern 
recognition techniques developed at AFGL 
have been incorporated in a microcomputer 
system for real-time, automatic classification 

Microphysics of Clouds: The Air Force 
needs improved techniques of observing 
and predicting physical characteristics of 
cloud and precipitation particles for the 
operation of aerospace vehicles, weapon 
systems and communication systems. 
Statistical data on cloud and precipitation 
size distributions and types of rain, snow or 
ice crystals are needed for weather erosion 
effects, electromagnetic weapon systems, 
satellite communication systems and 


of hydrometeors. The vertical bar on the left of 
each detected particle contains time and other 
information which are used in the computation 
of the number of particles per cubic meter and 
the ice/water content of the clouds. 

advanced numerical weather prediction 
models. In addition to the direct support to 
SAMSO, AFWL and AFFTC, AFGL began 
a basic research program to expand the 
inadequate data base for present and future 
applications to Air Force problems and 
needs. On two separate occasions, the 
instrumented MC-130E sampled winter 
storms on successive days as the storms 
formed, developed and changed while 
moving from New Mexico to the East Coast. 







12 « 


Hydrometeor particle types, size distribu¬ 
tion. ice water content values and standard 
meteorological data were collected by the 
MC-lttOE, while satellite data were ob¬ 
tained by McIDAS. These data have been 
analyzed for inclusion in statistical sum¬ 
maries. Data taken by the aircraft and by 
McIDAS for other programs are being re¬ 
processed to provide additional data for the 
summaries. 

Observations show wider variations in 
crystal types than those reported earlier in 
the literature or obtained from cloud cham¬ 
ber experiments. A definite geographic 
variation has been observed in single crystal 
types, with more pristine crystals observed 
in the Midwest and a larger percentage of 
malformed or undefined crystals found over 
the East Coast. 

Ten flights were made into cirrus clouds 
with the Learjet during August and 
September 1978 to provide summertime 
data above the flight ceiling of the MC- 
WOE. The missions were flow in Oklahoma 
and New England. Cirrus clouds from 
thunderstorms as well as those generated in 
situ were sampled, their characteristics 
being added to the data base. 

Cloud particle data collected by the MC- 
l.'lOE in halo-producing cirrus did not ex 
hibit the large abundance of pristine crystal 
shapes thought to be required for optical 
phenomena. We speculate that the fact that 
a halo was observed in spite of the non- 
pristine nature of the crystals was due to the 
relatively small variation in particle size and 
the relatively low concentration of particles. 

Instrumentation Development, Test 
and Evaluation: There are two regions in 
the atmosphere where it is particularly 
difficult to measure the liquid water content 
of the atmosphere — at high altitude where 
the cirrus particle shapes cannot be re¬ 
solved by two-dimensional shadowgraphs 
and axial spectrometers, and in the large 
snow and melting zone region where the 
particles are irregular in shape and density 
and are larger than the sampling area of the 
spectrometers. In this latter region, where 


liquid water contents can be quite high, two 
instruments, called EWER and TWCI. 
each using a different approach, have been 
under development, test and evaluation. 

The EWER, an instrument originally 
designed to Evaporate the Water that ag¬ 
gravates Erosion on Reentry, has two 
sampling tubes, each with a sampling area 
of 10 square centimeters. One tube samples 
air only, and the water vapor content is 
determined by measuring the attenuation of 
a Lyman Alpha source due to the ambient 
water vapor. The other tube collects the ice 
or liquid water which is rapidly converted to 
w’ater vapor and then measured in the same 
way. The difference between these two 
water vapor determinations is the amount 
of w’ater contributed by the ice or liquid 
w’ater collected. From the sampling area 
and the aircraft speed, the volume sample 
per second is computed and the amount of 
liquid (or solid) water in grams per cubic 
meter is determined. This instrument has 
been calibrated against the shadowgraph 
spectrometers in rain where raindrops are 
spherical and the spectrometers have their 
greatest accuracy. Time variations of the 



0 500 O00 M m 


Examples of agglomerated columnar crystals 
collected in cirrus clouds when a 22 degree 
halo, parhelia (mock suns), a sun pillar and an 
undersun were observed. These cirrus cloud 
particles did not exhibit the pristine crystal 
shapes normally thought to be associated with 
the observ ed optical phenomena. 



129 


EWER and spectrometers are highly corre¬ 
lated. but baseline variations indicate that 
the Lyman Alpha detector operates over a 
broad band near the Lyman Alpha line and, 
hence, does not operate according to theory. 

TWCI is an acronym for Total Water Con¬ 
tent Instrument and operates by mixing 
liquid water with a carrier fluid and meas¬ 
uring the change in the dielectric constant of 
the carrier fluid caused by the addition of 
water to the fluid. The TWCI has a sampling 
area of 20 square centimeters, so it too will 
provide statistically reasonable sampling 
volumes for large particles. Initially de¬ 
signed for installation in the nose of the 
Learjet. the TWCI received limited flight 
testing in the aircraft. It is now being re¬ 
designed for installation in the MC- 130E so 
that it can be flown through the same storms 
as the EWER to provide valid evaluations 
of the two instruments and the two tech¬ 
niques. 

The difficulty in measuring ice water con¬ 
tent in cirrus clouds stems from the fact that 
cirrus clouds consist of small ice crystals 
whose size and shape, or type, cannot be 
resolved by present instrumentation. 

In-house scientists began the evaluation 
of new techniques to determine their poten¬ 
tial for quantitative measurement of ice 
water content of cirrus clouds. One ap¬ 
proach measures the electrical output of a 
piezo-electric crystal when impacted by a 
cirrus particle, with the output being pro¬ 
portional to the mass of the particle. This 
gives a direct measurement of the liquid 
water content of an ice crystal, but consid¬ 
erable development will be required to 
determine sensor sizes for various ice 
crystal size ranges and to determine the 
efficiency of collection for each probe. This 
and other possible approaches will be in¬ 
corporated into our instrument devel¬ 
opment program in the near future. 

The cloud particle replicator can collect 
replicas of particles from 2 microns to 1.000 
microns. This is a continuous replication 
instrument which uses a formvar solution on 
movie-type film. As the solution dries, a 


? MB 1-0 AAIAL KATTtft MOM 12 SO*l 

3 MS 1-0 PlUCif MOKI SOO 4(00*1 

4 MvDftOWTtO* 20<l UM.1II 
3WID CLOUD MOM (20 300*) 

• TOTAL AM TCMKHATUTC AflOW 
T (*(• MCU 

■ (Hrt 2 D MIC# (MOM 1200 4400 m) 

9 2D CLOU) »WO*» (» tOOfi 
0 JW Cl000 W-iTC h MOM 
>i po» •/( coMPuTt* ■ me mwrtR 

FOAMVAP HYMOMTfOH ACPIICATO" 
(SVIMAL HYOHOMTiO* PAOOt 
i4iNS • OOA*Lf» HAD4A 
■3AN/AP0427 A* * 5CM <*IATH*P HAOAH 

* *mm HOSt CAMKA 
IT MOW LIGHT 
HI If LI VI f*. 

The AFGL MC-130E cloud physics aircraft is 
specifically instrumented to measure clouds, 
rain, snow and ice crystals up to a height of 
20,000 ft. The data are processed by the on¬ 
board computer for use by the mission director 
or sent to the ground-based weather team 
directly from the computer over a teletype 
downlink. 

“cast” of the particle is left on the film. Sev¬ 
eral laboratory tests were run to assure the 
proper flow of formvar solution to the film. 
The unit has been flown on several missions 
and has operated quite well. A television 
camera and monitor have provided real¬ 
time viewing of the moving film. By ob¬ 
serving particles on the monitor, crew 
members can make flow adjustments during 
a mission, thus assuring the collection of 
usable data. 

A foil sampler is used to obtain size infor¬ 
mation on the large snow particles. The data 
from this instrument are very important in 
the interpretation of weather radar data. 
New printed circuit boards were designed 
and installed to reduce maintenance, mech¬ 
anical and electrical problems, and to im¬ 
prove the reliability of the foil instrument. 

Improvements have been made in the 
One-Dimensional (1-D) Optical Array Spec¬ 
trometer System and the Two-Dimensional 
(2-D) Optical Spectrometer System on both 
the MC-130E and the Learjet. The 1-D 
system utilizes three laser probes, which 
illuminate the particles passing through the 
object plane of an imaging system and 
shadow a diode array. The particles are 
sized from 2 to 4.500 micrometers in 45 
channels and recorded on a digital recording 
system. Real-time computations of liquid 


MC UOt 40571 



130 


water content are provided by the on-board 
computers. 

The success of these instruments led to 
the development of the 2-D system, which 
produces a digital shadowgraph of each par¬ 
ticle. The size range was also extended to 
6.400 micrometers, with the lower cutoff at 
25 micrometers. This 2-D system vastly 
improved our method of defining the shape 
and orientation of particles. A remote 2-D 
display was added to the aircraft system to 
aid the on-board meteorologist in classifying 
particle types in real time. Pattern recog¬ 
nition techniques were developed for proc¬ 
essing the 2-D data to automatically de¬ 
termine classes of snow or ice crystals. 
These techniques were then incorporated in 
a microcomputer system in the Learjet to 
provide this information in real time. 

The on-board computers have been up¬ 
dated and downlinks have been installed to 
transfer data from the computers to tele¬ 
types located with the ground-based 
weather team at Kwajalein. Computer pro¬ 
grams were developed to provide specified 
data for the various types of missions. 

Support of the Air Force Weapons 
Laboratory: At the request of the Air Force 
Weapons Laboratory, the Cloud Physics 
Branch measured atmospheric water and 
ice particles, so that the Weapons Lab¬ 
oratory could quantitatively determine 
their degrading effects on laser energy 
transmission. The MC-130E aircraft 
measured the size and number of particles in 
two regimes of the atmosphere. The thin 
cirrus clouds found at altitudes above 18,000 
feet and the moist layer of air below 1,000 
feet over the ocean were both of interest to 
the AFWL Advanced Radiation Tech¬ 
nology Program. 

Eight flights in the late winter and early 
spring of 1978 have provided data on typical 
cirrus clouds. All of the flights were over the 
U.S. Southwest. AFGL personnel aboard 
the aircraft directed the flights and oper¬ 
ated the computer and other instrumenta¬ 
tion. Cirrus ice crystals as large as 2 milli¬ 
meters have been detected; however, there 


was usually not more than one such crystal 
per cubic meter. As crystal size decreased 
to 0.1 mm or less, the concentration typi¬ 
cally increased to 1.000 to 10,000 per cubic 
meter. The visibility reduction correlated 
well with the quantity of larger ice crystals 
in a cloud. However, on a number of occa¬ 
sions. ice crystals as large as one-half milli¬ 
meter were recorded when the visibility 
was 80 to 100 miles. 

A sampling flight 30 miles west of San 
Francisco investigated water droplet con¬ 
centrations above the ocean. Several passes 
were made at altitudes between 100 and 
1,000 feet. Although there were no clouds 
and only slight haze, the concentration of 
very small particles was much less at 300 
feet than at 100, 200. and 400 feet altitude. 
The concentrations at 500 feet and higher 
were also much smaller. The larger concen¬ 
trations of particles in the lowest 500 feet 
above the ocean appeared to be at about the 
levels where very thin, darker haze layers 
were observed visually. 

Special programs written to run on the 
AFGL computer were used in processing 
the large amount of taped digital data ac¬ 
quired on the sampling aircraft. Informa¬ 
tion from the flights was provided in several 
formats compatible with AFGL and AFWL 
requirements. 

High resolution satellite pictures acquir¬ 
ed every half hour from AFGL’s McIDAS 
facility facilitated determination of when to 
make particle sampling flights and where to 
direct the aircraft. 

Support of the Air Force Flight Teet 
Center: The Air Force Flight Test Center 
(AFFTC) is responsible for performing in¬ 
flight icing and water tests on Air Force 
aircraft. To produce water drops similar to 
those found in natural situations, a KC-135 
tanker has been modified with a spray 
nozzle on the end of the refueling boom. 
AFFTC asked AFGL to measure the drops 
in flight using equipment on the MC- 130E to 
verify that the desired sizes were produced. 
A test flight in April 1975 showed that the 
correct size drops were not produced. The 







131 


nozzle was redesigned, and in June 1978 a 
second set of calibration flights was con¬ 
ducted in preparation for AFFTC icing 
tests on the F-16. Although an airborne 
emergency curtailed the test, nine data 
points were obtained. Initial results look 
good, and the tests are scheduled to resume 
in January 1979. 

WEATHER EROSION PROGRAM 

After weeks and months of waiting for the 
prescribed type of weather, reentry erosion 
tests were successfully conducted in De¬ 
cember 1976 and March 1977 at NASA’s 
Wallops Island Range, Virginia, bringing to 
a close six consecutive winter seasons of 
testing there by the Advanced Ballistic 
Reentry Systems (ABRES) of the Air 



McIDAS, depicting erosion potential of clouds 
in the vicinity of Kwajalein on a day when 
ANT-2 was stood down because of unsuitable 
weather. Distortion of the atoll is due to the 
extreme viewing angle of the geosynchronous 
satellite which is stationed some HO degrees 
east of Kwajalein. 

Force Space and Missile Systems Organi¬ 
zation (SAMSO). Throughout the years of 
testing, it was AFGL’s responsibility to 
provide specialized weather input to the 
launch decision and, after the shot, to char¬ 


acterize the hydrometeors actually encount¬ 
ered along the test trajectory. 

Meanwhile, at the Kwajalein Missile 
Range in the southwest Pacific, erosion 
testing of quite a different character was 
emerging in the form of the “severe-clear” 
test. While the requirement for normal 
weather testing is to insure that the test 
vehicle will encounter a specified total 
amount of water and ice along its trajectory, 
the requirement for a severe-clear test is 
that there be no hydrometeors greater than 
a certain size, usually in the 50-150 micro¬ 
meter range. The entire burden of verifying 
this condition falls on the aircraft sensors, 
since low concentrations of hydrometeors 
are undetectable by even the ultrasensitive 
radars used by AFGL. Because of the 
emphasis on high altitudes, it is the Model 
86 Learjet. rather than the MC- 130E. which 
is AFGL’s workhorse in supporting severe- 
clear missions. 

For heavy-weather tests, one of the main 
gaps in the aircraft instrumentation con¬ 
tinues to be a device for directly sensing the 
water content of clouds and precipitation, 
which is the weather factor of greatest im¬ 
portance in the erosion of materials at 
hypersonic speed. Two different devices 
have been built and tested, but without 
spectacular success. One. however, shows 
sufficient promise that a new model is being 
designed. 

Because no instrument would sense 
water content directly. AFGL originally 
intended to derive water content from read¬ 
ings of the airborne particle spectrometers, 
which count and size the hydrometeors in a 
defined volume of the airstream. Unhap¬ 
pily. it was quickly discovered that the 
value of water content so inferred is fre¬ 
quently wrong because it depends on par¬ 
ticle geometry, which is complex and poorly 
known for ice hydrometeors. Circumven¬ 
tion of this intolerable situation has come 
from an advance in theory, specifically the 
invention of a novel spectral function which 
is far less sensitive to uncertainties in par¬ 
ticle geometry, and which can be combined 
















with radar reflectivity to yield a value of 
water content that is far more reliable than 
that obtained from integrating the particle 
size spectrum. 

Increasingly, real-time data from the two 
cloud physics aircraft, as well as radar data, 
have been used at Kwajalein in deciding 
when to launch the mission for optimum 
effect. Digital downlinks have now been de¬ 
signed for and installed aboard both the 
Learjet and the MC-1A0E. Every minute, 
or more often if required, each aircraft auto¬ 
matically transmits an updated report to a 
teleprinter on the ground. Onboard com¬ 
puters give the AFGL Field Director a wide 
range of options for content of the aircraft 
reports — from direct readout of individual 
sensors to complex derived quantities such 
as several spectral integrals. 

Besides su porting erosion tests. AFGL 
has continued to provide SAMSO and other 
agencies with erosion climatologies for tar¬ 
get and test areas. The satellite-correlation 
technique, which was expressly developed 
for this purpose and which requires as input 
nothing more than standard meteorological 
satellite data, was exploited to generate a 
year-long series of daily maps of four ero¬ 
sion indices covering the entire Eurasian 
area. Another of AFGL’s techniques was 
used to construct three hourly profiles of 
water content at Kwajalein for the entire 
year of 1975. This series was designed as a 
statistical base for test planning. 

While the satellite-correlation technique 
was originally conceived for climatological 
application using orbiting satellites, it has 
been adapted most profitably to real-time 
applications with geostationary metsats and 
AFGL’S Me I DAS. Subsequently, when¬ 
ever the Weather Team was at Kwajalein. 
they obtained via telephone from Hanscom 
current observations of weather approach¬ 
ing Kwajalein. in terms not available from 
any other source: erosion potential of 
clouds, their temperature, and motion. 

After each erosion test. AFGL docu¬ 
mented the trajectory weather on two oc¬ 
casions: in a quick-look report at 48 hours 



This Learjet :tti was instrumented under the 
direction of AFGL to obtain cloud physics data 
up to a height of 45,000 ft in support of 
SAMSO weather erosion projects conducted 
at the Kwajalein Missile Range in the Marshall 
Islands. Instruments on the nose and wing- 
tips provide laser shadowgraphs of cloud and 
precipitation particles. These data are pro¬ 
cessed by the on-board computer to provide 
real-time liquid water content values and 
other parameters which are required for the 
decision to launch the SAMSO K'RM vehicle 
from Vandenberg AFB. California. 

and in a final report at HO days. The quick- 
look depended essentially on radar data, 
nominal relations being used to derive 
water content. The final report was based 
on tailored relations derived from detailed 
analysis of the joint aircraft and radar data. 
For ANT-2, launched on July 4. 1978. the 
final values of water content were substan¬ 
tially larger than the quick-look values. 
Similar experience, but less extreme, had 
occurred on earlier tests in heavy weather. 
This suggests that the nominal relation¬ 
ships. based mainly on data taken in tem¬ 
perate latitudes, are probably not repre¬ 
sentative of average conditions on Kwaj¬ 
alein. Consequently. AFGL is now re¬ 
evaluating these relationships for Kwaj- 


133 


alein. using exclusively its own data taken 
at Kwajalein. 

After eight years of evolution, the air¬ 
craft-radar methodology that AFGL has 
used to support erosion tests — both the 
launch decision and the post-flight analysis 
— has reached the stage that its routine 
application no longer requires research sci¬ 
entists. In recognition of this, at AFGL’s 
initiative, this kind of test support is being 
converted to an inherent range capability. 
Thereafter. AFGL will concentrate its ef¬ 
forts on the developmental aspects of 
weather erosion problems, such as the use 
of lidar instead of radar for improved per¬ 
formance in light weather. 

ATMOSPHERIC MODELING 

The atmosphere is a complex fluid system 
that responds to external forcing and inter¬ 
nal dynamics on a continuum of space scales 
from the molecular to the global and with 
time variations, appropriate to the space 
scale, from seconds to millenia. Although 
the atmosphere obeys the classical laws of 
fluid dynamics, the nonlinear partial differ¬ 
ential equations governing its behavior can¬ 
not be solved analytically. Prior to the de¬ 
velopment of the computer, theoretical 
studies of the atmosphere were based on 
linear analogues of these equations. These 
analogues were mathematical models of the 
atmosphere, but because they were based 
on small amplitude appmximaUons. they 
were not suitable for weather prediction. 

Computers have allowed the emergence 
□fii new field of rtarettafc lueatrb Milled 
numerical weather prediction (NWP). 
NWP is the prediction of atmospheric be¬ 
havior based upon numerical solutions of the 
nonlinear partial differential equations ex¬ 
pressed as an initial-boundary value prob¬ 
lem. However, in spite of the power of 
modem computers, it is not possible to solve 
these equations in a manner which even ap¬ 
proaches their complete general form, so 
here. too. the atmosphere must be approxi¬ 
mated or modeled. 


There are three fundamental sources of 
error in these models which require sus¬ 
tained efforts for reduction. Because NWP 
is the solution of an initial-boundary value 
problem, the accuracy of the prediction is 
directly related to the completeness and 
accuracy with which we can specify the 
state of the atmosphere at the beginning of 
the forecast period. Accuracy of prediction 
also depends upon the validity and com¬ 
pleteness of the physics which is repre¬ 
sented by the system of equations compris¬ 
ing the mathematical model. Finally, the 
numerical solution requires discrete ap¬ 
proximations of the continuous differential 
equations in the model. Consequently, the 
accuracy of prediction also depends on how 
well the numerical method of solution ap¬ 
proximates the theoretical analytical solu¬ 
tion. Tne goal of AFGL’s efforts in math¬ 
ematical modeling of the atmosphere is to 
minimize all three sources of prediction 
error. 

Efficient, Accurate Model Solutions: 

Simulations or predictions of atmospheric 
motions by numerical models invariably 
encounter the following dilemma. If the 
model is formulated only for a limited geo¬ 
graphic region of the globe, artificial and 
often inconsistent boundary conditions 
must be supplied a priori on the lateral 
boundaries; if. on the other hand, the 
modeling is for the entire global atmos¬ 
phere. the geometric complexity of the 
problem often gives rise to mathematical 
and numerical difficulties. 

A case in point is the numerical solution of 
th*' rlftwir \ crtfriLy l.'qUajHnn model of at¬ 
mospheric planetary waves. A solution in 
spherical coordinates for this relatively 
simple model is not easily obtained. The 
coordinate singularity at the poles, the con¬ 
vergence of meridians with latitudes, and 
the nonlinear latitudinal variation of the 
Coriolis force all contribute to the difficulty 
of the model solution. Thus, in theoretical 
studies, the variation of the Coriolis force 
with latitude is assumed to be linear to alle¬ 
viate the mathematical complexity of the 






LONGITUDE 



Comparison of the effect of various diffusion 
operators and scale-dependent filter on sea- 
level pressure data around latitude circles 
after 10,000 iterations. A. Linear (Fickian) 




LONGITUDE 


diffusion. B. Non-linear diffusion. C. More 
complex nonlinear diffusion. D. Scale-depend¬ 
ent filter. Note meteorological features which 
are smoothed out by the diffusion operators. 





136 


problem. In NWP applications, a model 
similar to this one has been traditionally 
applied, using a polar sterographic pro¬ 
jection. 

We have developed an efficient, accurate 
finite-difference method for the numerical 
solution of such models in a global setting. 
This novel method incorporates an efficient 
direct solution technique for a Poisson equa¬ 
tion on a sphere and it uses a flexible- 
increment concept in finite-difference 
approximations to overcome the problem of 
computational instability due to the con¬ 
vergence of meridians in polar regions. Test 
calculations have demonstrated that the 
behavior of simple planetary waves can be 
predicted accurately for up to 100 model 
days in roughly 260 seconds using a CDC 
6600 computer. Thus, both in terms of com¬ 
putational stability and efficiency, this 
method of solution for the vorticity equation 
model seems to provide a valuable tool for 
numerical experimentation. 

Filtering and Smoothing: Numerical 
integrations of finite-difference analogues of 
systems of nonlinear partial differential 
equations, such as those arising in NWP. 
are subject to computational instability 
from a variety of causes. One type of insta¬ 
bility is produced by a spurious, nonlinear 
growth of high-frequency components that 
may be introduced by roundoff, truncation, 
and observational error. This type of insta¬ 
bility. arising from numerical noise, can be 
suppressed by a suitable choice of finite- 
difference method or by the use of a filter 
that selectively damps the high-frequency 
components. Though much effort has been 
devoted to the development of stable finite- 
difference procedures, and considerable 
success has been achieved, all such methods 
involve high-frequency smoothing, either 
implicitly or explicitly. 

In addition to the noise inherent in the 
numerical integration procedure (numerical 
noise), there is real noise which arises in a 
nonlinear system from a cascade of energy 
from large-scale motions to smaller and 
smaller scales. In the atmosphere, this real 


noise is controlled by diffusion and viscous 
dissipation, which is the final stage in the 
transfer of kinetic energy from larger to 
smaller scales. Numerical models of the 
atmosphere must handle not only the 
numerical noise from the integration pro¬ 
cedure. but also the real noise arising from 
the nonlinear processes being modeled. To 
complicate the problem further, the 
smallest scale which the model can resolve 
(twice the basic grid spacing) is many orders 
of magnitude larger than the microscopic 
scale on which viscous dissipation occurs in 
the atmosphere. Therefore, the model can¬ 
not treat viscous dissipation as the atmos¬ 
phere does, but must introduce some arbi¬ 
trary, artificial procedure which acts on 
much larger scales of motion. The crux of 
the problem is that the artificial dissipation 
must be strong enough to damp the noise 
which is constantly being generated, but 
must be weak enough so as not to damp the 
larger-scale. meteorologically significant 
variations. This means that the artificial 
dissipation must have the characteristics of 
a highly scale-dependent filter with strong 
damping for small-scale variations and little 
or no damping for only slightly larger scales. 
We have developed a filter which is ideal for 
this purpose. The filter completely removes 
variations on the smallest resolvable scale of 
the model, the two-grid-interval wave, but 
it can be made as highly scale-dependent as 
desired. The operator is symmetrical and 
does not alter the phase of any wave com¬ 
ponent. Furthermore, it is simple and effi¬ 
cient to use as part of the numerical inte¬ 
gration procedure. 

Because of its highly desirable charac¬ 
teristics. the filter has been adopted by a 
variety of agencies, both in this country and 
abroad, for use in both operational and ex¬ 
perimental weather prediction models. 

Numerical Modeling of Fronts: In the 
past few years, improvements in the speed 
and capacity of computers have made it pos¬ 
sible to model and study small-scale atmos¬ 
pheric features, such as frontal systems. 
Although fronts may extend for thousands 




136 


of kilometers in length, they represent tran¬ 
sition regions with large differences of wind 
and temperature over relatively small dis¬ 
tances across the front. In modeling fronts, 
the problem of noise suppression is ex¬ 
tremely acute since the dimension of the 
physical system is not much larger than the 
two-grid interval noise scale of the model. 
The scale-dependent filter discussed above 
has recently been applied to the modeling of 
fronts. The use of a relatively low-order 
filter has made it possible to carry out ex¬ 
tensive integrations of a model designed to 
study the development of fronts, without 
the contamination of small-scale noise. 

Limited Area Solutions: Routine predic¬ 
tion of atmospheric behavior, particularly 
the prediction of the gross features of the 
large scale circulation, is commonly based 
upon the numerical solution of a mathema¬ 
tical model designed to incorporate the 
physics for those atmospheric features of 
immediate interest. The typical mathe¬ 
matical model consists of a set of nonlinear 
partial differential equations expressing the 
rate of change of momentum and heat (the 
prognostic equations) and an appropriate 
set of diagnostic equations expressing 
relationships among the prognostic vari¬ 
ables and other variables which are re¬ 
quired in the mathematical solution of the 
prognostic equations. 

The system is solved numerically as an 
initial value problem over a network of grid 
points in space. The distance between 
neighboring points in this network controls 
the detail that can be resolved in the pre¬ 
dicted fields. Although arbitrary to some 
extent, this distance is more or less deter¬ 
mined by outside factors, such as the scale 
size of the phenomena of interest and the 
available computer capacity. 

It is often desirable to increase the fore¬ 
cast resolution over some limited area of the 
globe where the observational density or 
the nature of the problem warrants in¬ 
creased resolution, even though economic 
factors make it impractical to increase the 
resolution uniformly over the whole globe. 


In such cases, the problem is no longer a 
pure initial value problem, but, depending 
upon the numerical procedure, becomes 
more or less an initial boundary-value prob¬ 
lem. There are a variety of ways in which 
such a problem can be handled. However, 
the most successful approach entails sepa- 



Model density (temperature) field after six 
days of model time. Note the strong gradient 
along the dashed line. Also note the small scale 
distortions which quickly overwhelm the 
model solutions. 



Solution of model identical to the above in all 
respects except for the incorporation of filter¬ 
ing. No small-scale noise is present, but the 
large-scale features are virtually identical. 
Model solutions can be extended in time with¬ 
out blow-up. 





137 


rate coarse-mesh and fine-mesh calcula¬ 
tions, with the fine-mesh region nested 
within the coarse-mesh domain. The coarse- 
mesh solution is obtained for a “global” 
domain without artificial lateral boundaries 
and serves to supply the necessary 
boundary information for a solution with a 
fine-mesh grid over a limited area of the 
globe. The principal difficulty with this 
approach concerns the choice of proper 
boundary conditions for the particular sys¬ 
tem of equations. This problem, while 
serious, appears amenable to treatment and 
the nested-domain approach seems funda¬ 
mentally simpler for routine application 
than the variable-grid approach. 

The choice of proper boundary conditions 
for the nested region has been extensively 
examined for simple, linearized hyperbolic 
systems. The solution should depend contin¬ 
uously upon the boundary data so that a 
small change in a boundary value should 
have only an appropriately small effect on 
the solution. However, in the finite-differ¬ 
ence formulation of the typical NWP primi¬ 
tive equations, any difference between the 
prescribed boundary conditions and the 
correct boundary conditions will generate 
gravity waves and, although the errors may 
remain bounded, the solutions will be incor¬ 
rect. If the differences between the pre¬ 
scribed and correct boundary conditions are 
large, norlinear effects may generate real 
disturbances which could grow rapidly. A 
correct set of boundary conditions should 
specify the normal velocity and temper¬ 
ature in such a way that the outward propa¬ 
gating components are not hindered in 
passing out of the region. However, this is 
not practicable for a multilevel model. 

Even if it were possible to define the “cor¬ 
rect” boundary conditions for a realistic 
limited-area problem, in practice, the 
boundary conditions would at the very least 
contain truncation errors because they 
would be determined not from continuous 
fields but from a small number of point val¬ 
ues. However, real boundary errors will be 
more severe in the finite-difference solution 


since the proper boundary conditions cannot 
be defined for realistic problems, and at best 
one can apply boundary conditions which 
are appropriate for much simpler problems. 
Also, obtaining the proper boundary condi¬ 
tions for even the simpler problems is likely 
to involve computational and programming 
complexities. 

A certain amount of boundary error is 
inevitable in realistic, three-dimensional 
problems (regardless of the choice of bound¬ 
ary conditions and the method used to ob¬ 
tain them). To keep the errors to a mini¬ 
mum, a high-order interpolation procedure 
was devised for supplying time-dependent 
boundary values in a fine-mesh limited-area 
model. The interpolation is performed on a 
“global” coarse-mesh solution which is run 
concurrently with, but independent of the 
fine-mesh solution. 

The interpolation operator used to supply 
the fine-mesh initial and boundary informa¬ 
tion from the coarse-mesh solution should 
satisfy certain criteria. The operator should 
damp two-grid-interval noise, but not 
longer, meteorologically significant varia¬ 
tions. Furthermore, since much of the error 
introduced by interpolation is due to phase 
error, the ideal interpolation operator is one 
which removes two-grid interval waves, 
restores the amplitude of larger waves and 
corrects the phase shift produced by the 
customary interpolation procedures. Using 
principles similar to those discussed above 
for the scale-dependent filter, we have de¬ 
signed an interpolation operator with pre¬ 
cisely these ideal characteristics. It is highly 
scale dependent (more scale dependent than 
the ideal filter) and corrects for phase error. 
The use of this interpolation operator in a 
fine-mesh limited area, multilevel, primi¬ 
tive equation model has been shown to pro¬ 
vide suppression of much of the gravity 
wave noise generated by the artificial lat¬ 
eral boundaries. 

Boundary Layer Prediction Modal: We 

have completed an effort undertaken to in¬ 
vestigate the Air Force Global Weather 
Central’s Boundary Layer Model (designa- 



138 


DAY 6 



AMPLITUDE 



• M - • -. - 

•o - - - 


VALIDATION 

Fine-mesh limited area zona! wind field after 
six days of integration. Boundary information 
is supplied by interpolation from global eoarse- 
mesh solution. “Two-point" uses two-point 
linear interpolation and suffers from severe 

ted as AFGWC-BLM hereafter) for possible 
improvement in its forecasts. Because of 
operational constraints at AFGWC, we 
sought only improvements that would re¬ 
quire neither additional capacity in the 
central memory nor extra computer time. 
Furthermore, we limited our consideration 
to modifications that could be implemented 
in the prognostic phase of the model. 

Effects of various modifications of 
AFGWC-BLM on forecasts were analyzed 
by comparing characteristics of the result¬ 
ing forecast errors obtained on synoptic 
samples that were collected randomly dur¬ 
ing the period between April 1975 and De¬ 


2 KM 



"*—' ^ -----no-- 



PHASE + AMPLITUDE 


boundary noise. "Amplitude” uses amplitude 
restoring interpolation which improves the 
solution. “Phase and Amplitude” makes use of 
phase and amplitude restoring interpolation, 
which yields excellent results in comparison 
with the “Validation” solution. 

cember 1976. The merit of a modification 
was inferred from these analyses. Because 
of the amounts of time and cost involved in 
the production and analysis of forecasts, the 
study was carried out in a number of stages 
in which the modifications were imposed se¬ 
quentially on the basis of inferences drawn 
in earlier stages of the investigation. Sixty- 
three synoptic samples were divided into 
two groups of about the same size. All the 
proposed modifications were first run on the 
first group, but only those that were 
deemed worth further investigation were 
tried on the second group in order to test the 
validity of the inferences drawn from anal¬ 
yses of the first group. 




















139 


The study of modifications was carried 
out in three stages, each of which addressed 
one particular aspect of the model. They 
are: 1) computational resolution; 2) vertical 
structure; and 3) humidity forecasts. In 
computational resolution, it was found that 
doubling the size of the time step produced 
little adverse effect on the forecast accu¬ 
racy, while doubling the interval of the hori¬ 
zontal grid resulted in significantly larger 
forecast errors. The effects of modifications 
on the vertical structure were measured by 
comparing the temperature forecast errors. 
Of the three factors considered — namely, 
the estimation of eddy diffusivity, the 
hydrostatic equation, and the vertical dif¬ 
ferencing, — only the modification of eddy 
diffusivity produced statistically significant 
improvement in forecast accuracy. A modi¬ 
fication in the estimation of the surface 
specific humidity was contrived to preserve 
the advantage gained by the new eddy 
diffusivity without degrading the accuracy 
of the accompanying humidity forecasts. 

On the basis of these experimental re¬ 
sults, AFGL has suggested to AFGWC that 
AFGWC carry out a further study on the 
effects of the new diffusivity and the new 
surface specific humidity. These alterna¬ 
tives are both simpler in concept and less 
laborious in computation than those cur¬ 
rently employed in the operational version 
and can be readily incorporated into it. 
However, we believe that extensive revi¬ 
sions of the model are necessary to achieve a 
large increase in forecast accuracy. Such a 
reorganization must be made by consider¬ 
ation of both the diagnostic and prognostic 
phases of the model. 

CLIMATOLOGY 

Air Force systems must be designed to 
operate in, and withstand, atmospheric ex¬ 
tremes of known calculated risk of occur¬ 
rence. Overdesign can be costly, while 
underdesign can cause failure and loss of life 
or an aborted mission. Climatological stud¬ 
ies, therefore, are pursued to improve our 


knowledge of risks to Air Force equipment 
as well as for operation planning, thus mini¬ 
mizing weather effects on Air Force opera¬ 
tions. Limitations of available meteoro¬ 
logical observations make it necessary to 
develop both theoretical and empirical 
models to describe the structure and 
variability of the atmosphere. Models are 
being developed to improve estimates of 
climatic extremes, the areal extent of 
weather events, and the duration and 
recurrence probabilities of critical weather 
conditions. 

Line-of-Sight Climatology: Many cur¬ 
rent and proposed Air Force systems use 
optical, infrared, and laser sensors for 
detection, lock-on, and tracking. Because 
many of these sensors cannot operate 
through heavy haze or clouds, there is an 
increased need for information on the 
probability of haze- or cloud-free lines of 
sight. Two efforts have been conducted to 
determine how often haze or clouds would 
limit operations: an aircraft in-flight ob¬ 
servation program and the development of a 
cloud-free line-of-sight (CFLOS) model 
based on observed cloud-cover statistics. 

Probabilities of clear and cloud-free lines 
of sight from aircraft at various flight alti¬ 
tudes over much of the Northern Hemi¬ 
sphere have been determined from more 
than 275,000 in-flight LOS observations. 
These probabilities have been published in 
an AFGL technical report which includes a 
classified addendum. This information will 
be valuable to designers and operators of 
many electro-optical systems coming into or 
already in the inventory. The utility and 
optimum deployment of these weapon sys¬ 
tems can be estimated from a knowledge of 
clear and cloud-free line-of-sight statistics. 

A model for estimating CFLOS probabil¬ 
ities has been developed by correlating 
cloud-cover observations with whole-sky 
photographs. This model, which provides 
CFLOS probabilities through the atmos¬ 
phere for any desired elevation angle, based 
on cloud-cover statistics for a given location, 
was used to produce a series of atlases of 



140 


CFLOS probabilities for the USSR, the 
USA and Europe. A sample page from the 
USSR atlas is shown. 

Ice particles and water droplets in clouds 
can erode hypersonic vehicles, and precipi¬ 
tation can partly or completely absorb the 
millimeter wavelengths often used for 
communications. A climatology of precipi¬ 
tation occurrence is being developed for 
determining the probability and extent of 
precipitation along various ray paths 
through the atmosphere. A three-year col¬ 
lection of photographs of radar scopes taken 
at 17 National Weather Service radar sites 
was completed in December 1975. The radar 
scope was photographed every three hours 
with the antenna at each of four elevation 
angles: 0, 15, 30, and 45 degrees. 

These photographs will be used to devel¬ 
op a climatology of the slant range thickness 
of precipitation echoes. These data will pro¬ 
vide probabilities of precipitation interfer¬ 
ence along ray paths from the surface, be¬ 
tween two altitudes, and from any altitude 
out to space or to the ground. 


Air Force Reference Atmospheres: 

Mean monthly reference atmospheres, 
which describe the seasonal, latitudinal and 
longitudinal variations in the thermody¬ 
namic properties of the atmosphere for 
levels up to 90 km, have been developed and 
published for 15-degree intervals of lati¬ 
tude. Specialized models, which depict the 
magnitude of the changes in the vertical 
temperature and density profiles that occur 
during the winter warmings of the strato¬ 
sphere and mesosphere in arctic and sub¬ 
arctic regions, are included. Information is 
also provided on the day-to-day variations 
of density and temperature .around the 
monthly means. These models expand and 
update the information contained in the U. 
S. Standard Atmosphere Supplements, 
1966. They are intended for use by engi¬ 
neers in the design of aerospace systems. 

Ice Accretion: Ice accretion is an im¬ 
portant consideration in the design and 
operation of Air Force surface structures, 
such as towers, radio antennas and radar. It 
is one of the few meteorological parameters 



CFLOS probabilities for the USSR in July near noon (1200-1400 LST) at an elevation angle of 90 degrees. 



141 


( 


i 


i 


\ 



* 


j 



yet to be quantitatively observed on a 
routine basis. In 1976, the Air Weather 
Service submitted a “Geophysical Re¬ 
quirement” to AFGL which stated the need 
for establishing a climatology of ice accre¬ 
tion to support Air Force engineers in 
making design trade-offs. In response to 
this, a program was initiated to determine 
the feasibility of making objective observa¬ 
tions of ice accretion mass and thickness 
using a sophisticated, off-the-shelf, ice 
detector designed primarily for use on air¬ 
craft. The detector works by collecting the 
ice on an uitrasonically oscillating sensor. It 
is driven at its resonant frequency when 
dry, but accretion of ice will cause a shift in 
resonance corresponding to the increase in 
mass on the probe. After a small preset 
amount of ice has accumulated, the sensor is 
deiced. 

Tests on the detector were conducted in a 
climatic chamber for a wide range of synop¬ 
tic situations which simulate natural icing 
conditions. For these tests, the number of 
instrument deicing cycles was very highly 
correlated with measurements of mass and 
thickness on simulated structural members. 
Further testing of the ice detector in the 
natural environment will be accomplished at 



Ice detectors and simulated structural com¬ 
ponents on a stand during the climatic 
chamber tests. 


four locations in eastern Massachusetts dur¬ 
ing the winters of 1978-1979 and 1979-1980. 
At the same time, AFGL will be working 
with Air Weather Service in planning the 
deployment of the detectors at a number of 
stations in the Northern Hemisphere. Once 
a network is in place, data collected will be 
analyzed to determine icing design criteria. 

Line Coverage: If the probability of 
occurrence of an event at a single observa¬ 
tion point is known, what is the cor¬ 
responding probability of occurrence of the 
same condition everywhere along a line or a 
fraction of the line, or in a surrounding area 
or fraction thereof? There have been 
abundant specific examples of this basic 
question, many with respect to the areal 
coverage of rainfall. 

Satellite pictures, recording as they do 
areal cloudiness, make possible a study of 
the field of view of a given area or percent¬ 
age of the area. Radar has been a valuable 
asset for its panoramic view of precipitation 
within a circular area surrounding the radar 
site. But, generally, the archived climatolo¬ 
gical records contain single-instant observa¬ 
tions of the weather at single-point weather 
stations. Rainfall amount, for example, is 
the amount collected at the location of the 
bucket or rain gauge. Area coverage or line 
coverage, therefore, must be obtained by a 
special task of data collection, or must be 
estimated by practical rules or models. 

Previous investigations had been based 
on statistical models which provided an¬ 
swers on the frequency and duration of 
weather events and on the areal extent of 
weather conditions. Recently, a solution of 
the model selected for the duration of events 
was obtained analytically, thus providing 
for computer programming of problems and 
answers. Such answers, until recently, 
were only approximate, having been ob¬ 
tained by random number simulation. 

Simulation is still the method of devel¬ 
opment for the model of areal coverage. It 
has provided solutions to several important 
problems. For example, what is the prob- 





PROBABILITY 


142 


ability that a low-flying vehicle will travel 
free of cloud and rain particles for all or most 
of the crucial segment of the trip? Or what is 
the probability of a non-attenuating line of 
sight? Graphs that provide the answers to 
such questions on line coverage were pre¬ 
pared recently with the help of random 
number simulation. 

To illustrate the usefulness of the new 
graphs on line coverage, suppose the prob¬ 
lem is to investigate the likelihood of rain 
during one hour, in July, along all or part of 
the 300-km distance from Boston to New 
York. The diagram illustrates the use of the 
model. Starting at the right-hand side, it 
shows that the probability of simultaneous 
rainfall, in July, everywhere (10/10) along 
the 300-km distance is only 7/100 of 1 #, but 
the probability of the condition of rainfall 
over at least 3/4 of the distance is nearly 1%. 
The probability of its occupying over 1/2 of 
the distance is nearly 5#, the same as the 



One hour rainfall probability, in July, along 
the great circle from Boston to New York as a 
function of the fraction of the line occupied by 
rainfall. The circle indicates the single-station 
probability, 5*/f. 


probability of its occurring at a pre-selected 
station. The probability of its occurring over 
at least 30 km, or 1/10 of the length, is up to 
13*/? . The probability of its occurring any¬ 
where at all, in ho. ver small an area, is 
21#, which also means that there is a 79# 
probability of no rain in that hour anywhere 
along the 300-km line of travel. 


Joint Probabilities: For the design of 
equipment and the planning of some mili¬ 
tary operations, climatic risk can be esti¬ 
mated from probabilities of occurrence of a 
single weather event, such as a temperature 
extreme of 110 degrees, or heavy rain, at a 
given location. However, some Air Force 
missions will not succeed unless favorable 
weather is observed at more than one loca¬ 
tions, or a\ more than one point in time. In 
planning such missions, joint occurrences of 
weather events are required. A Monte 
Carlo technique was developed to estimate 
probability distributions of favorable 
weather within a specified area or along a 
line of travel. This technique has been 
tested on several meteorological elements 
and found to be effective. Another model 
has been developed for estimating the 
probability of occurrence of any given 
weather event jointly at two locations if the 
unconditional probability of the event at 
each location and the spatial correlation is 
known. 

A similar model has been developed for 
estimating recurrence probabilities — that 
is, probabilities that a weather event will 
occur at time t and recur at time t+C This 
model also yields good estimates. However, 
these estimates are generally not as good as 
the estimates of joint occurrences in space 
because diurnal variation is not well ac¬ 
counted for in the model. 

Studies are under way to develop models 
for estimating joint occurrences of weather 
events at more than two locations or more 
than two time periods. 



143 


Stratosphere-Mesosphere Relation¬ 
ships: Meteorological rocket and radio¬ 
sonde observations have been used to 
examine the decay in the coefficient of cor¬ 
relation between the densities at two points 
with increasing vertical and horizontal sep¬ 
aration. The results of these studies have 
been used to prepare statistical arrays of 
the means and standard deviations of den¬ 
sity at altitude intervals of 5 km, together 
with interlevel correlations. These arrays 
can be used to determine the integrated 
effect of density on the trajectory of reentry 
vehicles provided the influence coefficients 
for the vehicles are known. This eliminates 
the need for engineers and designers to fly a 
new design through a representative 
sample of individual density profiles to ob¬ 
tain estimates of the distribution of density 
effects on a particular reentry vehicle. 

WEATHER MODIFICATION 

Operations at most airports are ham¬ 
pered more by the presence of fog than by 
any other weather phenomenon. Likewise, 
the presence of low stratus clouds seriously 
hampers tactical and surveillance opera¬ 
tions. The ability to disperse these types of 
clouds would greatly improve the Air 
Force’s mission success probability, In 
recognition of the fact, AFGL has studied 
techniques for operational fog and stratus 
dispersal for several years. Recent atten¬ 
tion has been focused on the development of 
an operational warm fog dispersal system 
using ground-based heat sources and the 
development of a tactical technique for 
supercooled stratus dispersal. 

Warm Fog: During the past several 
years, many techniques for warm fog dis¬ 
persal have been evaluated by AFGL. The 
studies concluded that the most promising 
technique for airport operations was the use 
of thermo-kinetic energy. As a result of 
AFGL’s applied research effort, an engi¬ 
neering development program was 
launched in 1975. The program was 
managed by the Civil and Environmental 


Engineering Development Office, with 
technical support provided by AFGL. 
Under a separate effort, a smaller theo¬ 
retical study was conducted on the possible 
use of radiant energy for dispersing fog and 
stratus. 

The thermo-kinetic warm fog dispersal 
system (WFDS) designed by AFGL has two 
principal components: the combustors and 
the controls. The combustors produce heat 
and provide thrust to project the heat into 
the target area. The controls allow remote 
operation and monitoring of the combus¬ 
tors, and automatic regulation of the heat 
and thrust requirements, depending on the 
prevailing wind and visibility conditions. 
The combustors are located along both sides 
of the approach and rollout portions of the 
runway. The clearing produced will allow 
landings to be safely completed under Cate¬ 
gory I approach conditions. This means that 
the visibility will be raised to 800 meters (V 2 
mile) to a maximum depth of 75 meters (250 
feet) over the approach zone and 15 meters 
(50 feet) over the rollout portion of the run¬ 
way. 

The key to an efficient and reliable WFDS 
is to design the combustors to produce suf¬ 
ficient heat and thrust for all expected wind 
and visibility condition. The Meteorology 
Division has been primarily concerned with 
defining the optimum combustor settings 
and configurations for a wide variety of 
meteorological conditions, and for defining 
the meteorological instrumentation re¬ 
quirements for the WFDS. 

Based on earlier subscale tests and ana¬ 
lytical modeling studies, a set of combustor 
specifications was drawn up. The combus¬ 
tors were designed under contract, and a 
single runway and an approach zone com¬ 
bustor were fabricated and tested for reli¬ 
ability. The combustors each produce two 
exhaust flows of heated air. Each unit con¬ 
sists of a central diesel engine with propel- 
lors at each end to produce the combustion 
air and the thrust air. The air is heated as it 
passes by a burner located in front of each 
propellor and then enters an elbow, where it 



WSTAMCe <ro> HEIGHT (m) 


144 


is turned 90 degrees toward the runway. 

Tests were conducted at the contractor’s 
test facility in clear air to determine the 
plume profile under a variety of heat, thrust 
and wind conditions. It was assumed that a 
temperature rise of 2 to 3 degrees C is re¬ 
quired for clearing fog. The optimum heat 
and thrust settings were then determined 
for a variety of wind conditions. The test 
results indicated relatively close agreement 
with the previous experimental and theo¬ 
retical studies. However, the plume tra¬ 
jectory appeared to be less sensitive to wind 
and heat than previous studies had indi¬ 
cated. 

Since the WFDS is required to clear up to 
depths of 75 meters for a Category I 
approach, a knowledge of the winds up to 75 
meters would be beneficial in controlling the 
position of the heat plumes. Consequently, 




The vertical and horizontal cross-sections of 
the heat plume from a dual outlet, runway 
WFDS combustor. The vertical cross-section 
was derived from a smoke tracer. The hori¬ 
zontal cross-section was determined from an 
array of thermistors at 3 meters above 
Ifround. 


an evaluation was made of two indirect wind 
measuring probes: the acoustic Doppler 
wind sounder (ADWS) developed by the 
National Oceanic and Atmospheric Admin¬ 
istration’s (NOAA) Wave Propagation 
Laboratory, and the laser Doppler veloei- 
meter (LDV) developed by Lockheed. Both 
the ADWS and the LDV were tested at the 
AFGL Weather Test Facility at Otis AFB, 
Massachusetts, in September 1976 and 
again in September 1977. Both instruments 
measure the wind by utilizing the Doppler 
shifting of backscattered energy from 
moving targets. In the case of the ADWS, 
the scattering is by inhomogeneities in the 
index of refraction: with the LDV, it is by 
atmospheric aerosols. The data from the 
two probes w r ere compared with the winds 
measured by sensors mounted at different 
levels on a 60-meter tower. The indirect 
measurements compared quite favorably 
with the direct measurements in both fog 
and clear air. Either system would, there¬ 
fore, be suitable for incorporation into the 
WFDS control system. 

In recent years, various scientists have 
suggested the use of radiant energy for dis¬ 
persing fog or stratus. In 1977, an in-house 
theoretical study was conducted to deter¬ 
mine the feasibility of such an approach. In 
the study, the source of microwave power 
was considered to be either ground-based or 
airborne. For the ground-based case, the 
microw'ave beam was taken as parallel to 
the ground and along the runway, providing 
a direct source of microwave power for 
heating the fog. For the airborne case, the 
beam was taken as perpendicular to the 
ground, the heating of the ground by the 
microwave beam providing a source of in¬ 
frared power for dissipating the fog. The 
study showed that, for either case, very 
large power densities, well above the per¬ 
sonal safety limit of 100 watts/m- used in the 
United, States, would be required to dis¬ 
sipate the fog in a time of about ten minutes. 
If the power density is taken as 100 watts/ 
m-, a very long time, that is, many hours 
would be required to dissipate the fog. In 



145 


i 


l 

i 

j 

i 


J 

i 


* 





addition, because of the high cost of elec¬ 
trical energy, the large amount of energy 
required for a typical airport fog (about 3 x 
10" joules) makes the scheme prohibitively 
expensive. 

Supercooled Stratus: Supercooled 
stratus dispersal tests were conducted in 
February 1977 to determine the feasibility 
of producing clearings over a predeter¬ 
mined ground target using a small aircraft 
as the seeding platform. The requirement 
that a small aircraft be used virtually elim¬ 
inated the possibility of using dry ice, which 
has been the standard seeding material for 
many years. Dry ice requires a rather large 
dispenser, which can only be carried on 
larger aircraft, such as a C-130. Silver 
iodide flares, on the other hand, require only 
a simple dispenser which can be mounted 
under the wing or fuselage of a small air¬ 
plane. Other advantages of silver iodide 
flares are reliability, simplicity, minimal 
logistic requirements, and suitability for 
advanced delivery systems. The silver 
iodide flares are ejected from an aircraft and 
fall between (500 to 1800 meters before being 
totally consumed in the combustion process. 
The smoke from burning pyrotechnic con¬ 
tains silver iodide crystals which serve as 
ice nuclei. The manufactured pyrotechnic 
grains contain a very small amount of 


Clearing produced in stratus clouds, 730 
meters in depth, 30 minutes after dispensing 
11 flares (220 gm Agl) along a 1.8 km line. 


chlorine. Addition of the chlonne produces 
greater nucleation effectiveness, especially 
at warmer temperatures. 

Field tests were conducted in northern 
Michigan, with the base of operations at 
Traverse City. This location was chosen 
because of the frequency of supercooled 
stratus in this area, airspace availability, 
terrain and logistic support. The primary 
purpose of the tests was to determine the 
feasibility of targeting the clearing over a 
predetermined ground target. Another 
objective was to optimize the seeding rates 
and patterns in terms of the quality of the 
clearing produced. 

Two aircraft were used in the tests. One 
seeded the cloud at cloud top, and the other 
served as an observation and command plat¬ 
form at higher altitude. Photographs taken 
from the observation aircraft served as the 
primary data and evaluation tool. Photo- 
grammetrie analysis of selected photo¬ 
graphs allowed measurement of horizontal 
dimensions of the clearings. Ten missions 
w ere flown, resulting in 15 tests. 

Five major conclusions were derived 
from the test data. First, it was not par¬ 
ticularly difficult to target the clearings, 
given accurate wind measurements. 
Second, the quality of the clearings (in 
terms of visibility) was not as good, as 
hoped, although it did appear to correspond 
with previous studies. In most cases, it was 
possible to observe the ground when looking 
vertically down. However, it was not gen¬ 
erally possible to see the ground along a 
slanted line of sight. Third, the silver iodide 
pyrotechnic seeding system was capable of 
producing clearings very similar to those 
reported in earlier studies and appears to be 
a suitable choice for tactical use. Fourth, 
clearings were produced at temperatures as 
warm as -8 degrees C and in clouds up to 
4,000 feet thick. Finally, clearings up to 18 
km in diameter were produced from seeding 
patterns measuring 4 km by 5 km. 





146 


In addition to the field tests, a one¬ 
dimensional mathematical model of the 
growth of ice crystals in supercooled clouds 
was examined in detail and a sensitivity 
analysis was performed. Critical para¬ 
meters include seeding rate, temperature, 
cloud depth, liquid water content, drop size 


and updraft velocities. When reasonable 
values of cloud physics parameters and 
known values of the seeding rates, mini¬ 
mum temperatures, and cloud depth were 
used in the model, reasonable agreement 
between the theoretical and observed rates 
of cloud dissipation was obtained. 


METEOROLOGY DIVISION 

JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 


AUSTIN, P. M. (Dept, of Met., Mass. Inst, of 
Technol., Cambridge, Mass.land BJERKAAS, C. 

L.,Capt. 

Contribution to Case Studies of S September and 17 

September: Analysis of Precipitation Patterns in 

Northwest Portions of B-Scale Area 

Rpt. of U. S. GATE Cent. Program Wkshp. (August 

1977) 

Cole, A. E. 

Review of Data a nd Models of the Middle Atmosphere 
Space Res., Vol. 9(1978) 

Cole, A. E. t and Kantor, A. J. 

Part J. I: Model and Data for Altitudes up toX6 Km 
U. S. Std. Atm., 1976, U. S. Govt. Prtg. Off. (October 
1976) 


LEMON, L. R. (Natl. Sev. Storms Forecast Ctr., 
NWS, NOAA, Kansas City Mo.), DONALDSON, R. 

J., Jr., Burgess, D. W., and Brown, R. A. 

(Nat. Sev. Storms Lab., ERL, NOAA, Norman, Okla.) 
Doppler Radar Application to Severe Thunderstorm 
Study and Potential Real-Time Warning 
Bull, of Am. Met. Soc., Vol. 58, No. 11 (November 

1977) 

Liou, K. N., Stoffel, T. L., Feddes, R. 

G. (Univ. of Utah), and BUNTING, J. T. 

Radiative Properties of Cirrus Clouds in NOAA i 
VTPR Channels 

Radn. in the Atm., Ed. by H. J. Bolle, Sci. Press(1977) 

Liou, K. N., Stoffel, T. L., Feddes, R. 

G. (Univ. of Utah), and BUNTING, J. T. 

Radiative Properties of Cirrus Clouds in NOAA i 
VTPR Channels: Some Explorations of Cloud Scenes 
from Satellites 

Pure and Appl. Geophys., Vol. 116, No. 6 (November 

1978) 


Cunningham, R. M. 

Progress in Precipitation Growth Measurements 
Proc. of Inti Cloud Phys. Conf., Boulder, Colo. (July 
1976) 

Analysis of Particle Spectral Data from Optical Array 
t'PMSl I and 2D Sensors 

Proc. of 4th Symp. on Met. Obsns. and Instmn. (10 
April 1978) 

Donaldson, R. J., Jr. 

Observations of the Union City Tomadic Storm by 
Plan Shear Indicator 

NOAA Tech. Memo., ERL-NSSL 80 (December 1976), 
Ed., Rodger Brown 

Mo. Wea. Rev., Vol. 106, No. 1 (January 1978) 

Fitzgerald, D. R. 

Electrical Structure of Large Overwater Shatter 
Clouds 

Elec. Processes in Atm., H. Dolezalck and R. Reiter, 
Eds , Darmstadt, Ger. (1977) 

Kaimal, J. C., Wyngaard, J. C., 
Haugen, D. A. (WaveProp. Lab., Boulder, 

Colo ), Cote, 0. R u Izumi, Y.,and 
Caughey, S. J., Readings, C. J. (Met. Res. 

Unit, RAF Cardington, Bedford, Eng.) 

Turbulence Structure in the Convective Boundary 
Layer 

J of Atm. Sci,, Vol. 33 (November 1976) 


Lund, I. A., and Grantham, D. D. 

Persistence, Runs and Recurrence of Precipitation 
J. of Appl. Met., Vol. 16, No. 4 (April 1977) 

Mudrick, S. 

A Further Test of a Scale-Dependent Filter for Use in 

Finite Difference Modeling 

Mo. Wea. Rev., Vol. 106, No. 8(August 1978) 

Plank, V. G., Spatola, A. A., and 
Johnson, D. M. 

(Combustion Engrg. Co., Windsor, Conn.) 

Values of Diffusion Coefficients Deduced from the 
Closing Times of Helicopter-Produced Clearings in 
Fog 

J. of Appl. Met., Vol. 17, No. 8 (August 1978) 

Shapiro, R. 

Interpolation of Data Between Uniform Grids of 
Differing Lengths 

Mo. Wea. Rev., Vol. 106, No. 5 (May 1978) 

SHAPIRO, R., and STOLOV, H. L. (City Univ. of 

N. Y.) 

A Search for a Solar In fluence on the Skill of Weather 
Forecasts 

J. of Atm. Sci., Vol. 35, No. 12 (December 1978) 



147 


RAO, K. S. (ATDL, Natl. Oceanic and Atm. Adm., 
Oak Ridge, Tenn.), WyNGAARD, J. C. (Wave 
Prop. Lab., NOAA, Boulder, Colo.), and COTE, 0. 

R. 

A Numerical Study of Warm-Air Advection Fog 
Proe. of 3rd Conf. on Numerical Wea. Prediction, 
Omaha, Neb. (April 1977) 

TaHNK, W. R., CAPT., and LYNCH, R. H. 

A Description of the AFGL MAWS: Scott AFB 
Demonstration Model 

Proc. of 7th Tech. Exchange Conf. (1 April 1977) 

Tattelman, P. I. 

Worldwide Probabilities of Surface Weather Extremes 
— A Supplement to MIL-STD-JIOB 
Proc. of23rd Ann. Tech. Mtg. of Inst, of Envmt. Sci. 
(April 1977) 

TaTTLEMAN, P. I., and KANTOR, A. J. 

A Method for Determining Probabilities of Surface 
Temperature Extremes 

J. of Appl. Met., Vol. 16, No. 11 (November 1977) 

Weinstein, A. I. 

Fog Dispersal — A Technology Assessment 
AIAAJ. of Aircraft, Vol. 14, No. 1 (January 1977) 

Weinstein, A. I., and Hicks, J. R. tu. s. 

Army Cold Regions Res. and Engrg. Lab., Hanover, 
N. H.) 

Use of Compressed Air for Supercooled Fog Dispersal 
J. of Appl. Met., Vol. 15(November 1976) 

Yee, S. Y. K. 

An Efficient Method fora Finite-Difference Solution of 
the Poisson Equation on the Surface of a Sphere 
J. of Comp. Phys., Vol. 22, No. 2 (October 1976) 


PAPERS PRESENTED AT MEETINGS 
JULY 1976 - DECEMBER 1978 


AUSTIN, P. M. (Dept. ofMet., Mass. Inst, of 
Technol.), and BjERKAAS, C. L. 

Contribution to Case Strulies of .5 September and 17 
September: Analysis of Precipitation Patterns in 
Northwest Portion of B-Scale Area 
GARP Atlantic Tropical Exper. (GATE) Wkshp., 
Natl. Ctr. for Atm. Res., Boulder, Colo. (25 July -12 
August 1977) 

Barnes, A. A., Jr. 

New Cloud Physics Instrumentation Requirements 
4th Am. Met. Soc. Symp. on Met, Obsns. and Instrmn., 
Denver, Colo. (10-14 April 1978) 

Barnes, A. A.. Delgado, L. V., Capt., 
and Kraus, M, J. 

High Reflectivity Values Observed in Equatorial 
Warm Showers 

17th Conf. on Radar Met., Seattle, Wash. (26-29 
October 1976) 


Barnes, A. A., and Plank, V. G. 

Forecasting atui Verifying Hydrometeor Spectra 
Inti. Cloud PhyB. Conf., Boulder, Colo. (26-30July 
1976) 

Bjerkaas, C. L., Capt., and Donaldson, 

R, J., Jr. 

Real Time Tornado Warning Utilizing Doppler 

Velocities from a Color Display 

18th Conf. on Radar Met., Atlanta, Ga. (28-31 March 

1978) 

Boucher, R. J, 

C orrelation of Radar Reflectivity arui Snowfall Rate 

During Moderate to Heavy Snow 

18th Conf. on Radar Met., Atlanta, Ga. (28-31 March 

1978) 

Bunting, J. T. 

Cloud Properties from Satellite Infrared and Visible 
Measurements 

7th Conf. on Aerosp. and Aeronaut. Met. and Symp. on 
Remote Sensing from Satellites, Melbourne, Fla. (16- 
19 November 1976) 

Cloud Measurements from Satellites and Aircraft 
3rd Conf. on Atm. Radn., Univ. of Calif., Davis, Calif. 
(28-30 June 1978) 

Bunting, J. T., and Conover, J. H. 

Estimates from Satellites of Total Ice and Water 
Content of Clouds 

Inti. Cloud Phys. Conf., Boulder, Colo. (26-30 July 
1976) 

Bunting, J. T„ and Valovcin, F. R. 

Meteorological Satellite Measurements and 
Applications 

7th Tech. Exch. Conf., El Paso, Tex. (30 November - 3 
December 1976) 

Chisholm, D. A. 

Weather Automation Studies at the Otis Weather Test 
Facility 

Conf. on Atm. Envmt. of Aerosp. Sys. and Appl. Met., 
N. Y„ N. Y. (13-16 November 1978) 

Recent Developments in Automated Weather 
Observing and Forecasting 
8th Techn. Exch. Conf., Colo. Springs. Colo. (28 
November -1 December 1978) 

Cole, A. E. 

Renew of Data and Models of the Middle Atmosphere 
21st Plenary Mtg. and Wkg. Gp. Mtgs. of Comm, on 
Space Res. (COSPAR), Innsbruck, Aus. (5-9June 
1978) 

CRANE, R. K. (Envmt. Res. and Technol., Inc., 
Concord, Mass.), and GLOVER, K. M. 

Calibration of the SPANDAR Radar at Wallops 
Island 

18th Conf. on Radar Met., Atlanta, Ga. (28-31 March 
1978) 





148 


Cunningham, R. M. 

Progress in Precipitation Grouih Measurements 
Inti. Cloud Phys. Conf., Boulder, Colo. (26-30 July 

1976) 

A nalysis of Particle Sfwctml Data from Optical A rray 
(PMS ) i t) a/at JD Sensors 

Am. Met. Soe. 4th Symp. on Met. Obsns, and Instmn,, 
Denver. Colo. (10-14 April 1978) 

Donaldson, R. J., Jr. 

Air Force Studies in Doppler Radar Meteorological 
Research 

Mtg. of Central Okla. Chap, of Am. Met. Soe., 
Norman, Okla. (30 March 1977) 

Donaldson, R. J., Jr., and Bjerkaas, C. 
L., Capt. 

Real-Time Tornado Warning Utilizing Doppler Radar 
Velocities from a Color Display 
Sem., Dept, of Met., Mass. Inst. ofTeehnol., 
Cambridge, Mass. (28 February 1978) 

Donaldson, R. J.. Jr., Dyer, R. M., 
Kraus, M. J. and Morrissey, J. F. 

Analysis pl an Asymmetric Doppler Velocity Pattern 
17th Conf. on Radar Met., Seattle, Wash. (26-29 
October 1976) 

Donaldson^ R. J., Kraus, M. J., and 
Boucher, R. J. 

Doppler Velocities in Rain Bands of Hurricane Belle 
18th Conf. on Radar Met., Atlanta, Ga. (28-31 March 
1978) 

Dyer, R. M., and Thompson, J. R., and 

WlSNER, C. (No. Am. Wea. Consultants, Coleta, 
Calif.) 

Dispersal of Supercooled Stratus Clouds by Silrer 
lixiide Seeding 

6th Conf. on Inadvertent and Planned Wea. 
Modification, Champaign-Urbana, Ill. (10-13 October 

1977) 

Glass, M., and Varley, D. J., Lt. Col, 

Obsen'ations of Cirrus Particle Characteristics 
Occurring with Halos 

Conf. on Cloud Phys. and Atm. Elec., Issaquah, Wash. 
(31 July - 4 August 1978) 

Glover, K. M., Branche, J. R., Turner, 
J. H., and GROGINSKY, H. L. 

(RaytheonCo., Wayland, Mass.) 

Precise Calibration of Coherent and Non-Coherent 
Weather Radars by Means of a Radar Transponder 
17th Conf. on Radar Met., Seattle, Wash. (26-29 
October 1976) 

Glover, K. M., and Konrad, T. G. (Appi. 

Phys. Lab., Johns Hopkins Univ., Laujel, Md.) 

Radar Observations of Known and Unknown Clear 
Air Echoes 

Wkshp on Radar, Insect Population Ecology and Pest 
Mgt., NASA Wallops Flight Ctr,, Wallops Is., Va. (2-4 
May 1978) 


Grantham, D. D., Lund, I. A., and Davis, 

R. E. (NASA Langley Res. Ctr., Va.) 

Estimating the Probability of Cloud-Free Fields-of- 
View between Earth and Airborne or Space Platforms 
1978Tech. Exch. Conf., AF Acad., Colo. Springs, 
Colo. (28 November - 1 December 1978) 

42nd MORS Symp., Naval War Coll., Newport, R. 1. 
(5-7 December 1978) 

Gringorten, 1.1. 

Areal Cocerage of New England Rainfall 
Cumulations in I Hourto!, Days 
5th Conf. on Prob. and State, in Atm. Sei., Las Vegas, 
Nev. (15-18 November 1977) 

Conditional Probabilities of Ceilings and Visibilities 
at a Point, Along a Dine and in an Area 
5th Inti. Symp. on Multivariate Anal., Pittsburgh, Pa. 
(20 June 1978) 

Hering. W. S., Moroz, E. Y., and Tahnk, 
W. R.,dAPT. 

Airfield Weather Observing Systems 
7th Conf. on Aerosp. and Aeronaut. Met. and Symp. on 
Remote Sensing from Satellites, Melbourne, Fla. (16- 
19 November 1976) 

Hicks, J. R. (U. S. Army Cold Regions Res. and 
Engrg. lab., Hanover, N. H.), and WEINSTEIN, A. 

Claciation of Supercooled Fog by Compressed Air 
Inti. Conf. on Wea. Modification, Boulder, Colo. (2-6 
August 1976) 

Kantor, A. J. 

Thermodynamic Properties of the Arctic and 
Subarctic Atmosphere to 90 Km 
Jt. Asbly. of Inti. Assoc, of Geomag. and Aeron. and 
Inti. Assoc. ofMet. and Atm. Phys., Seattle, Wash. (31 
August 1977) 

Kantor, A. J., and Cole, A. E. 

Thermodynamic Properties of the Arctic and 
Subarctic Atmosphere to 90 Km 
2nd Sp. Asbly. of IAMAP, Seattle, Wash. (22 August - 
3 September 1977) 

Klein, M. M. 

Determination of Lift-Off Point and Modified 
Trajectory of a Heated Turbulent Planar Jet in a Co- 
Floumg Wirul 

1977 Spring Mtg. of Am. Phys. Soc., Wash., D. C. 
(25-28 April 1977) 

Interaction of a Turbident Planar Heated Jet with a 
Counterflomng Wind 

30th Anniv. Mtg., Am. Phys., Soc., Div. of Fluid Dyn., 
Lehigh Univ., Bethlehem, Pa. (21-23 November 1977) 

Kraus, M. J., and Donaldson, R. J. 

Interpretation ofPPI Velocity Displays in Widespread 
Storms 

17th Conf. on Radar Met., Seattle, Wash. (26-29 
October 1976) 


149 


Kraus, M. J., Donaldson, R, J., Jr., and 
Bjerkaas, C. L., Capt. 

Severe Thunderstorm and Tornado Warnings in Real 
Time by Color Display of T oppler Velocities 
10th Conf. on Severe Loca Storms, Omaha, Neb. (18- 
21 October 1977) 

Kunkel, B. A. 

The AFGL Program on Fog and Stratus Dispersal 
5th Ann. Marine Fog Program Rev., Calspan Korp., 
Buffalo, N.Y. (5-7 April 1977) 

The Design of a Warm Fog Dispersal System 
0th Conf. on Inadvertent and Planned Wea. 
Modification, Champaign-Urbana, Ill. (10-13 October 
1977) 

Liou, K. N., Stoffel, T. L., Feddes, R. 

G. (Univ. of Utah) 

Radiative Prop’rties of Cirrus Clouds in NOAiX 4 
VTPR Channels 

Inti. Symp. on Radn. in the Atm., Garmisch, Ger. 
(18-28 August 1976) 

Lund, I. A. 

Seeing through the Atmosphere 

Opt.-Submm. Atm. Prop. Conf., USAF Acad.,Colo. 

(6-9 December 1976) 

Lund, I. A., and Grantham, D. D. 

A Mode! for Estimating Joint Probabilities of Weather 
Events 

7th Conf. on Aerosp. and Aeronaut. Met. and Symp. on 
Remote Sensing from Satellites, Melbourne, Fla. (16- 
19 November 1976) 

Moroz, E. Y. 

Fired Based Support Systems: Sensor Development 
and Integration 

7th Tech. Exch. Conf., El Paso, Tex. (30 November - 3 
December 1976) 

Mudrick, S. E. 

On the Removal of Small Scale “Noise" from an NWP 
Model 

3rd Conf. on Numerical Wea. Prediction, Omaha, Neb. 
(26-28 April 1977) 

MUENCH, H.S., and KEEGAN, T. J. 

Automated Short-Range Forecasting of Cloud Cover 
and Precipitation Using Geo-Stationary Satellite 
Imagery Data 

8th Tech. Exch. Conf., Colo. Springs, Colo. (28 
November - 1 December 1978) 

Petrocchi, P. J. 

Operational Capability of a Weather Radar Time 
Lapse Color Display System 
17th Conf. on Radar Met., Seattle, Wash. (26-29 
October 1976) 

Plank, V. G., and Barnes, A, A. 

An Improvement in Obtaining Real-Time Water 
Content Values from Radar Reflectivity 
18th Conf. on Radar Met., Atlanta, Ga. (28-3! March 
1978) 


Shapiro, R. 

The Treatment of Lateral Boundary Conditions in 
Limited-Area Models: A Pragmatic Approach 
Inti. Conf. on Met. of Semi-Arid Zones, Tel-Aviv, Isr. 
(31 October - 4 November 1977) 

TAHNK, W. R., Capt., and LYNCH, R. H. 
Fixed Base Supports Systems: Automated Observing 
and Forecasting Technique Development 
7th Tech. Exch. Conf., El Paso, Tex. (30 November - 3 
December 1976) 

Tattleman, P. 

Worldwide Probabilities of Surface Weather Ext retries 
— A Supplement to MIL-STD-JWB 
Ann. Mtg. oflnst. ofEnvmt. Sci., Los Angeles, Calif. 
(25-27 April 1977) 

Preli rn i na ry Assessment of a n Ice Accretion 
Measurement System 

2nd Inti. Symp. on Snow Removal and Ice Control 
Res., Hanover, N. H. (15-19May 1978) 

Weinstein, A. I. 

Fog Dispersal — An Operational Weather 
Modification Technology Today 
Inti. Conf. on Wea. Modification, Boulder, Colo. (2-6 
August 1976) 

Yee, S. Y. K. 

A n Efficient Shooting Method for the Solution of a 
Discrete Poisson Equation 

3rd Conf. on Numerical Wea. Prediction, Omaha, Neb. 
(26-28 April 1977) 


TECHNICAL REPORTS 
JULY 1976 > DECEMBER 1978 


Bertoni, E. A. 

Clear and Cloud-Free Lines-of-Sight from Aircraft 
AFGL-TR-77-0141 (21 June 1977) 

BROUSAIDES, F. J. 

Field Test Results of a Laser Doppler Velocimeter and 
a n Acoustic Doppler Wind Sounder 
AFGL-TR-78-0275 (1 November 1978) 

Bunting, J. T., Valovcin, F. R.,and 
Keegan, T. J. 

Meteorological Satellite Measurements and 
Applications 

AFGL-TR-77-0035 (3 February 1977) 

Cole, A. E., and Kantor, A. J. 

Arctic and Subarctic Atmospheres, Ota 90 Km 
AFGL-TR-77-004601 February 1977) 

A ir Force Reference Atmospheres 
AFGL-TR-78-0051 (28 February 1978) 

Conover, J. H., and Bunting, J. T. 

Estimates from Satellites of Weather Erosion 
Parameters for Reentry Systems 
AFGL-TR-77-0260 (29 November 1977) 

Estimates from Satellites of Weather Erosion 
Parameters for Reentry Systems: Annex 
AFGL-TR-77-0260 (29 November 1977) 



150 


\ 

i 


I 

I 

I 


1 

J 


1 


P 

it 


i 


Dyer, R. M., Kraus, M., and Morrissey, 
J. F. 

Doppler Observation of Auburtidale Windstorm of 
Aug. 12, 197a 

AFGL-TR-76-0286 (7 December 1976) 

Dyer, R. M.,and Kunkel, B. A. 

A Comparison of Theoretical and Experimental 
Results in Supercooled Stratus Dispersal 
AFGL-TR-78-0193 (9 August 1978) 

Gringorten, 1.1. 

Areal Corerage Estimates by Stochastic Modeling 
AFGL-TP 76-0148(6July 1976) 

Multi■ r Conditional Probabilities 

AFGI r 1239 (6 October 1976) 

Condit ~mt Probabilities 

AFG^-'l’i -0238 (2 October 1978) 

Hawkins, R. S. 

A New Automated Processing Technique for Satellite 
Imagery Analysis 
AFGL-TR-77-0174 (3 August 1977) 

HERING, W. S., and GEISLER, E. B..CAPT. 
Forward Scatter Meter Measurements of Slant Visual 
Range 

AFGL-TR-78-0191 (9 August 1978) 

KANTOR, A. J. 

Observed Mean Monthly Winds at Standard Pressure 
Su rfaces from 950 MB to 100 MB 
AFGL-TR-76-0234 (30 September 1976) 

KANTOR, A. J., and COLE, A. E. 

Monthly 90 N Atmospheres and High-Latitude Warm 
and Cold Winter Stratosphere I Mesosphere 
AFGL-TR-77-0289 (14 December 1977) 

Keegan, T. J. 

Cloud Distributions as Indicators of Tropical Stonn 
Displacement 

AFGL-TR-76-0170(3 August 1976) 

Variations in Ground Brightness Over Northeastern 
United States as Sensed by GOES Satellites 
AFGL-TR-78-0290 (27 November 1978) 

Investigation of Composite Cloud Fields as Applied to 
Tropical Storm Forecasting 
AFGL-TR-77-0136 (13 June 1977) 

Klein, M. M. 

A Method for Determining the Point of Lift-Off and 
Modified Trajectory of a Ground-Based Heated 
Turbulent Planar Jet in a Co-Flowing Wind 
AFGL-TR-77-0033 (2 February 1977) 

Interaction of a Turbulent Planar Heated Jet with a 
Counterfiowing Wind 
AFGL-TR-77-0214 (26 September 1977) 

Calculation of the Buoyant Motion of a Turbulent 
Planar Heated Jet in an Opposing Air Stream 
AFGL-TR-78-0072 (23 March 1978) 

A Feasibility Study of the Use of Radiant Energy for 
Fog Dispersal 

AFGL-TR-78-0240 (6 October 1978) 


Kunkel, B. A. 

The Air Quality and Noise Impact of a Warm Fog 
Dispersal System Using Momentum Driven Heat 
Sources 

AFGL-TR-76-0199G September 1976) 

A Modern Thermo-Kinetic Warm Fog Dispersal 
System 

AFGL-TR-0278 (14 November 1978) 

Lund, I. A., and Grantham, D. D. 

Persistence, Runs, and Recurrence of Sky Cover 
AFGL-TR-77-0308 (30 December 1977) 

Persistence, Runs, and Recurrence of Visibility 
AFGL-TR-78-0024 (31 January 1978) 

Lund, I. A., Grantham, D. D., and Elam, 

C. B., Jr. (USAF Envmt. Tech. Appl. Ctr., Scott 
AFB, Ill.) 

Atlas of Ctond-Free Line-of -Sight Probabilities. Part 
2:1 'nion of Soviet Socialist Republics 
AFGL-TR-77-0005 CIO December 1976) 

Atlas of Cloud-Free Li ne-of-Sight Probabilities. Part 
■1: l'nited States of America 
AFGL-TR-77-0188 (24 August 1977) 

Atlas of Cloud-Free Li ne-of-Sight Probabilities, Part 
U Europe AFGL-TR-OJ7ti t Id November 1979) 

Moroz, E. Y. 

Investigation of Sensors and Techniques to Automate 
Weather Observations 
AFGL-TR-77-0041 (11 February 1977) 

MUENCH, H. S., and BROWN, H. A. 
Measurements of Visibility and Radar Reflectivity 
During Snowstorms in the AFGL Mesonet 
AFGL-TR-77-0148 <5 July 1977) 

MUENCH, H. S., and LAMKIN, W. E. 

The l ’se of Digital Rada r in Short-Ra nge Forecasting 
AFGL-TR-76-0173 (4 August 1976) 

Plank, V. G. 

Hydrometeor Data and Analytical-Theoretical 
Investigations Pertaining to the SAMS Rain Erosion 
Program of the 1972-7.1 Season at Wallops Island, 
Virginia, AFGLISAMS Report No. .5 
AFGL-TR-77-0149 (5 July 1977) 

Plank, V. G.. Spatola, A. A., and 
JOHNSON, D. M. (Combusti n Engrg. Co., 
Windsor, Conn.) 

Values of Diffusion Coefficients Deduced from the 
Closing Times of Helicopter-Produced Clearings in 
Fog 

AFGL-TR-77-0019112 January 1977) 

Shapiro, R. 

The Treatment of Latejal Boundary Conditions in 
Limited-Area Models: A Pragmatic Approach 
AFGL-TR-77-0092 (19 April 1977) 

TAHNK, W. R., CAPT., and LYNCH, R. H. 
The Development of a Fixed Base Automated Weather 
Sensing and Display System 
AFGL-TR-78-0009 (6 January 1978) 


i 




-MV 


151 


TATTELMAN, P., and KANTOR, A. J. 

Atlas of Probabilities of Surface Temperature 
Extremes. Part II — Southern Hemisphere 
AFGL-TR-77-0001 (27 December 1976) 

V.ALOCVIN. F. R. 

S noiv/Cloud Discrimination 
AFGL-TR-76-0174 (4 August 1976) 

Varlev, D. J., Lt. Col. 

Cirrus Particle Distribution Study. Part I 
AFGL-TR-78-0192 (7 August 1978) 

Cirrus Particle Distribution Study, Part ./ 
AFGL-TR-78-0305 (11 December 1978) 

Varley, D. J., Lt. Col., and Brooks, D, 
M., Capt. 

Cirrus Paiiicle Distribution Study. Part J 
AFGL-TR-78-0248( 10 October 1978) 

Yang, C.-H. 

A Study of the Error of Discretization in the Air Force 
Global Weather Central Boundary Layer Model 
AFGL-TR-77-0091 (19 April 1977) 

Yang, C.-H., and Agazarian, K. 

A Report on Experiments with the AFGWC Boundary 
Layer Model 

AFGL-TR-78-0239 (2 October 1978) 

Yee, S. Y. K. 

An Efficient, Accurate Numerical Method far the 
Solution of a Poisson Equation on n Sphere 
AFGL-TR-77-0246 (4 November 1977) 

An Efficient Barotropic Vorticity Equation Model on a 
Sphere 

AFGL-TR-78-0273 (13 November 1978) 

CONTRACTOR JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 

FEDDES, R. G., KaVENEY, W. J., and LlOU, 
K. N. (Univ. of Utah) 

Statistical I nference of Cloud Thick ness from NOAA i 
Sea n n inq Rad iometer 

Radn. in the Atm., Ed. by H. J. Bolle.Sci. Press (1977) 

FEDDES, R. G., and LlOU, J. N. (Univ. of Utah) 
Sensitivity of Vpwelling Radiance in Nimbus 6 HIRS 
Channels to Multi-Layered Clouds 
J. ofGephys. Res., Vol. 82, No. 37(December 1977) 
Atmospheric Ice and WaterContent Derived from 
Parameterization of Nimbus 6 High-Resolution 
Infrared Sounder Data 

J. of Appl. Met., Vol. 17, No. 4(April 1978) 

KaVENEY, W. J., FEDDES, R. G., and LlOU, 

K. N. (Univ. of Utah) 

Statistical Inference of C loud Thick ness from NOAA i 

Scanning Radiometer Data 

Mo. Wea. Rev., Vol. 105, No. 1 (January 1977) 

LlOU, K. N. (Univ. of Utah) 

Remote Sensing of the Thickness and Composition of 
Cirrus Clouds from Satellites 


J. of Appl. Met., Vol. 16, No. 1 (January 1977) 
Comments on a Bisper/ral Method tor Cloud 
Parameter Determination 
Mo. Wea. Rev., Vol. 105, No. 12(December 1977) 

CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 • DECEMBER 1978 

Belsky, L. E. .Francis, M. W., Kaplan, 
F. B., Leach, D., and Roberts, K. (Digital 

Programming Services, Inc., Waltham, Mass.) 
Development and Application of Mathematical 
Procedures toa Variety of Cloud Physics Research 
Data 

AFGL-TR-78-0170 (30 June 1978) 

Belsky, L. E., Francis, M. W., Kaplan, 

F. B., and O’Neil, J. E. (Digital Programming 
Services, Inc., Waltham, Mass.) 

Continuation of Development and Application of Data 
Processing Techniques and Analytic Procedures to 
Cloud Physics Data 
AFGL-TR-76-0182 010 July 1976) 

Blackman, E. S., and Pickett, R. M. (Bolt, 

Beranek, and Newman, Inc., Cambridge, Mass.) 
Automated Processing of Satellite Imagery Data at 
Air Force Globed Weather Centred (AFGWCI: 
Demonstrations of S[>ectnd Analysis 
AFGL-TR-77-0080 (March 1977) ' 

BLATTNER, W. G. M. (Radn. Res. Assoc., Inc., 
Fort Worth, Tex.) 

Multiple Scattering Effects Upon Measurements with 
the AFGL LSRVMS LidarSystem 
AFGL-TR-77-0003 (15 January 1977) 

Boak, T. I. S., Ill, Jagodnik, A. J., Jr., 
Marshall, R. B., Riceman, D., and 
YOUNG, M. J. (Raytheon Co., Wayland, Mass.) 
RfkD Equipment Information Reports. Tracking and 
Significance Estimator 
AFGL-TR-77-0259 (7 November 1977) 

Booker, D. R.,andWlNDES,J.(Aeromet,Inc„ 
Norman, Okla.) 

HAW ADS Equipment Description and Operational 
Ma n ual 

AFGL-TR-77-0066 (12 January 1977) 

Brashears, M. R., Eberle, W. R., 

(Lockheed Missiles & Space Co., Inc. Huntsville, Ala.) 
Remote Wind Measurement in Fog Using Laser 
Doppler Velocimetry 
AFGL-TR 76-0313 (December 1976) 

Burke, H. K., Hardy, K. R., and Bussey, 

A. J. (Envmt. Res, and Techno!., Inc., Concord, 
Mass.) 

A Methodology for C ross Section Analysis and Liquid 
WaterContent Assessment at Kwajalein 
AFGL-TR-78-0189 (August 1978) 

Chadwick, R. B., Moran, K. P., 
Morrison, G. E., and Campbell, W. C. 

(Wave Prop. Lab., NOAA, Boulder, Colo.) 
Measurements Showing the Feasibility for Radar 
Detection of Hazardous Wind Shear at Airports 
AFGL-TR-78-0160 (21 June 1978) 




152 


Chin, D., and Hamilton, H. D.tSys.andAppi. 
Sci. Corp., Riverdale, Md.) 

Synoptic Analysis Cone 1 - 1 March ID'S - J March 

i ins 

AFGL-TR-78-0294 (1 November 1978) 

COCKAYNE, J. E. (Sci. Appl., Inc., McLean, Va.) 
Sn m »ia ry pt F ichi Support for SAMS VI a ad MSV 
Operations 

AFGL-TR-78-0061 (November 1977) 

CRANE, R. K. (Envmt. Res. andTeehnol., Inc., 
Concord, Mass.) 

Development of Techniques tor Short-Range 
Precipitation Forecasts 
A FG L-TR-78-0005 (December 1977) 

Feat not ion pi Uncertainties in the Estimation pt 
Hydro meteor Mass Concentrations Using Sfutndar 
Data and Aircraft Measurements 
A FGL-TR-78-0118 (May 1978) 

Parameterization at Weather Radar Data tor Use in 
the Prediction at Storm Motion and Development 
AFGL-TR-78-0216 (March 1977) 

Davis, P. A., and OSTREM, J. S. (SRI Inti., 
Menlo Pk., Calif.) 

Modeling tor Muttispeetrat Infrared and Microwave 
Remote Sensing ot the Tmfmsphere 
AFGL-TR-77-0201 (September 1977) 

Ec.GLETON, F. P.,JaGODNIK, A. J., Jr., and 
Marshall, R. B. (Raytheon Co., Wayland, 

Mass.) 

RJtD Equipment Information Report Time Lapse 
Storage System 

AFGL-TR-77-00S1 (December 1977) 

FeDDES, R. G., and LlOC, K.-N. (Univ. of 
Utah) 

Cloud Contposition Determination by Satellite 
Sensing Using the SlMRUS H High Resolution 
In/ra red Sounder 
A FGL-TR-77-0123 (15 May 1977) 

FOURNIER, R. F. (RegisColl., Weston, Mass.) 

All Initial Study of Power Spectra from Sidellite 
Imagery 

AFGL-TR-77-0295 CIO September 1978) 

Gustafson, D. E., Ledsham, W. H. <sci. 

Sys.. Inc., Cambridge, Mass.), FOWLER, M. G. 
(Envmtl. Res. andTeehnol. Inc.,Concord, Mass.), and 
BLACKMAN, E. S. (Bolt, Beranekand Newman, 
Inc., Cambridge, Mass.) 

Mnltispectml Cloud Identification Study 
AFGL-TR-78-0280 (September 1978) 

IBRAHIM, M. M. (McGill Univ., Montreal, Que., 
Can.) 

A Comparative Study of Frictian and Numerical 
Smoothing in a Global Model of Atmospheric Flow 
AFGL-TR-77-0177 (August 1977) 


Jagodnik, A.J., Jr., and Novick, L. R. 

(RaytheonCo., Wayland, Mass.) 

Scan Converter and Refresh Memory with Remote 
Term inal and Display Data Interlace 
AFGL-TR-76-IW01 (August 1970 

KnoLLENBERG, R. G. (Particle Measuring Sys., 
Inc., Boulder, Colo.) 

The Response of Optical Array Spectrometers to Ice 
and Snow: A Study of J-D Probe Area-to-Area 
Relationships 

A FGL-TR-76-0273 (8 November 1976) 

Leonard, T. J., andMETTAUER, J.C. (Regis 
Coll., Weston, Mass.) 

A Generalized Computer Program for Primitive- 
Equation Models 
AFGL-TR-77-0188 CM) May 1977) 

Liou, K. N., Feddes, R. G.. Stoffel, T. 

L.. and AUFDERHAAR, G. C. (Univ. of Utah) 
Remote Sounding of Cloud Compositions from NOAA 
and NIMBUS ti Infrared Sounders 
AFGL-TR-77-0252 Cll October 1977) 

Lorenz, E. N. (Mass. Inst.ofTechnol.) 

Available Energy and the Maintenance of a Moist 
Circulation 

AFGL-TR-78-0007 (December 1977) 

Martin, D. E., and Myers, E. (St. Louis 
Univ., St. Louis, Mo.) 

Climatic Mislels that Will Provide Timely Mission 
Success Indicators for Planning and Supporting 
Weather Sensitive Operations (Sci. Rpt. No. 1) 
AFGL-TR-77-0258 (20 October 1977) 

Climatic Mislels that Will Provide Timely Mission 
Success Indicators for Planning and Supporting 
Weather Sensitive Operations (Sci. Rpt. No. 2) 
AFGL-TR-78-0:M)8 (December 1978) 

MARTIN, D. E. (St. Louis Univ., St. Louis, Mo.) 
Research to Develop Improved Models of Climatology 
that Will Assist the Meteorologist in the Timely 
Operation ot the Air Fnice Weather Detachments 
AFGL-TR-76-0248C11 August 1976) 

McManus, R. G.. Chabot, A. A., Young, 
R. M., and NOVICK, L. R. (Raytheon Co., 
Sudbury, Mass.) 

Slant Range Visibility Measuring Lidar 
A FGL-TR-76-0262 (September 1976) 

Metcalf, J. I., Brookshire, S. P., and 
Morton, T. P. (Ga. Inst. ofTechnol.) 
Polarization-Diversity Radar and Lidar Technology 
in Meteorological Research 
AFGL-TR-78-0030 (31 July 1977) 

Metcalf, J. I., and Morton, T. P. (Ga. Inst. 

ofTechnol.) 

Applications of Polarization-Diversity Technology in 
Meteorology 

AFGL-TR-78-0031 CM) October 1977) 



163 


NORMENT, H. G. (Atm. Sci. Assoc., Bedford, 
Mass.) 

Additional Studies of the Effects of Airplane 
Floictields oil Hydrometeor Concentration 
Measurements 

AFGL-TR-76-0187 (13 August 1976) 

Sanders, F., Adams, A. L., Gordon, N. 
J. B., and JENSEN, W. D. (Mass. Inst, of 
Technol.) 

.4 Study of F'orecast Errors in a Barotmpic 
Operational Model tor Predicting Paths at Tropical 
Storms 

AFGL-TR-77-02(I7 (December 1977) 

Sanders, F., and Gordon, N. J. (Mass. Inst. 
ofTechnol.) 

.4 Study of Forecast Errors in a n Operational Model 
tor Predict ini) Paths of Tropical Storms 
AFGL-TR-77-0079 (December 1976) 

SEGRE, J. (Am. Opt. Co., Southbridge, Mass.) 
Erbium Lidar Cloud Base Measuring System 
AFGL-TR-76-0177 (August 1976) 

Somerville, P. N., Watkins, S.,and 
Daley, R. (Fla. Technol. Univ.) 

Some Models tor Rainfall 
AFGL-TR-78-0218 (31 August 1978) 


VANDERKRUIK, R. K.,andJAG0DNIK, A.J., 
JR., (RaytheonCo., Wayland, Mass.) 

R&D Equipment Information Report. Weather Radar 
Tra nsponder (VoI. I tGron nd-CIutter Ca nceller (Vol. 

Jl 

AFGL-TR-77-0171 (April 1977) 

Ward, J. M. Hermann, M. R., Burke, 

L., PRATT, H. J., andGLASSER, R. M. (Regis 
Coll., Weston, Mass.) 

Visibility Measurementsjor Probability Forecasts 
McIDAS System Configuration and Capabilities 
Radiative Change of Surface Air Temperature 
AFGL-TR-76-0250 (September 1976) 

Wisner, C.. Thompson, J. R., and 
Griffith, D. A. (No. Am. Wea. Consultants, 
Goleta, Calif.) 

A Study of Stratus Clouds in Central Europe 
AFGL-TR-77-0021 (January 1977) 

Wisner, C., and Shaffer, L. N. (No. Am. 

Wea. Consultants, Goleta, Calif.) 

Initial Development of a Tactical System tor 
Dispersing Supercixded Stratus 
AFGL-TR-78-0025 (27 January 1978) 




The AFGL transportable absolute gravity 
system in its most recent configuration. 
Packed for shipment in nine boxes, the system 
weighs about 700 kg. A measurement takes 2 
or 3 days to obtain a precision of 0.05 pm.sec - 
to . 15 pm.sec - (5 to 15 pgal). 








VI 


TERRESTRIAL SCIENCES 
DIVISION 


The Terrestrial Sciences Division r < n- 
ducts research on the properties of the 
earth's surface, subsurface, and near atmos¬ 
phere using the disciplines of seismology, 
geology, geodesy, and gravity. This re¬ 
search supports the deployment, operation, 
and delivery of Air Force weapons with par¬ 
ticular emphasis on strategic systems. In¬ 
strumentation is designed and produced to 
measure geophysical phenomena worldwide 
at varying scales and accuracy levels to 
meet specific needs. Field work is conducted 
whenever and wherever necessary. 
Instrumentation is mounted on a variety of 
test beds designed to operate on land, in the 
air, or in space, and data are collected where 
the organization’s experience and theory 
suggest the need. Theoretical models of 
geophysical phenomena are developed and 
cast into a quantitative form for compari¬ 
sons with observations. Tested mathemati¬ 
cal models of geophysical phenomena are 
produced in a variety of formats that are 
useful in various applications. 

During the reporting period work has 
been conducted on automated position and 
azimuth determination, lunar laser ranging, 
very long baseline interferometry, absolute 
gravimetry, satellite altimetry, and geopo¬ 
tential modeling. Effort has also been ap¬ 
plied in crustal motion research, the devel¬ 
opment of tiltmeter technology for Air 
Force geophysical applications, and the de¬ 
termination of specific and detailed aspects 
of the motion environment of a midcontinent 
missile silo. 

GEODESY AND GRAVITY 

Geodesy is concerned with the size, 
shape, and mass distribution of the earth. 
Accurate geodetic information is a neces- 




156 


sary foundation for the accurate determina¬ 
tion of position, distance, and direction for 
launch sites, tracking sensors, and targets. 
The geodetic and gravimetric parameters 
for the earth and geodetic information for 
positioning not only form the structural 
framework for mapping, charting and navi¬ 
gational aids, but are also direct data inputs 
for missile inertial guidance systems. Cur¬ 
rent geodetic information is inadequate to 
meet the requirements of future USAF 
weapon systems. 

The Division conducts continuing re¬ 
search and development programs in 
geometric geodesy and in physical geodesy 
(or gravity). These programs are directed 
toward improving the fundamental knowl¬ 
edge of the earth's size, shape, gravity field 
and the techniques used for determining 
position, distance, and direction on the 
earth’s surface and in terrestrial and inertial 
three-dimensional coordinate systems. 

In Satellite Radar Altimeter and Gravity 
Gradiometer Programs, AFGL participates 
and cooperates with the Defense Mapping 
Agency, the Army, the Navy, the National 
Aeronautics and Space Administration, the 
National Oceanic and Atmospheric Admin¬ 
istration, the U.S. Geological Survey, other 
civilian agencies, and academic observa¬ 
tories. The Terrestrial Sciences Division 
also participates with the International 
Gravity Commission in the development of a 
worldwide gravity reference network. A 
worldwide system of earth-tide profiles is 
being established in cooperation with the 
International Center for Earth Tides, Brus¬ 
sels, Belgium. 

Automated Position Determination: 

Geodesy is concerned not only with position¬ 
ing but also with the orientation of a site in 
inertial space. The conventional inertial 
reference standards for inertial orientation 
are the stars, and the usual orientation 
angles are known as astronomic latitude, 
longitude, and azimuth. Other inertial ref¬ 
erence standards besides the stars exist 
(the lunar orbit and gyroscopes, for in¬ 


stance) but currently the stars are the best 
and most widely used inertial reference 
standards available to geodesists. 

Studies show that the human being can be 
the largest error source in astronomic posi¬ 
tion determination. Therefore, all of 
AFGL’s position determining, transferring, 
and monitoring experiments deal with vari¬ 
ous phases of automating one or more of the 
components involved in this very special¬ 
ized type of position determination. 

The present research and development 
program of the Geodesy and Gravity Branch 
in automated positioning determination en¬ 
compasses: the determination of azimuth or 
a reference direction that can serve as a 
precise azimuth reference: the transfer of 
azimuths and monitoring of azimuths to de¬ 
termine their stability: and experimenta¬ 
tion in methods of measuring refraction at 
the point of observation. 

To determine azimuth or a reference di¬ 
rection based on the precise location of the 
earth’s rotational axis, AFGL sponsors two 
contractor experiments which use ring las¬ 
ers or fiber optics in ring interferometer 
systems to detect the earth's rotation. Both 
of these programs are directed towards the 
development of optical ring gyroscopes to 
the point where they will be geodeticallv 
and geophysically significant instruments in 
finding the local direction of the earth’s rota¬ 
tional axis. Given this axis, the precise value 
of astronomic latitude and direction of 
north, south, east, or west can be deter¬ 
mined. 

Another AFGL experiment in azimuth 
determination consists of an effort by the 
University of Hawaii to design, construct, 
and test a device that automatically trans¬ 
fers an azimuth reference. This experiment 
will produce a completely automated device 
for turning highly precise, repeatable 
azimuth reference angles. The device con¬ 
sists of a catadioptric telescope mourned on 
a computer-controlled indexing table that 
has a silicon photo-diode linear sensor in the 
focal plane for use as a vernier aiming de¬ 
vice. The indexing table automatically posi- 


157 


tions the telescope in azimuth by means of 
the computer controller that drives the in¬ 
dexing table in 1-degree increments and 
uses the movable linear photo-diode to posi¬ 
tion a target within one arc-second of the 
optical axis of the telescope. The instrument 
is leveled with an electronic capacitance 
level, eliminating the need for manual fine 
adjustments. After initial settings of the 


Azimuth transfer device showing, from right 
to left: catadioptric telescope mounted on 
indexing table; electronic controls; computer 
controller and data recording unit. 

telescope on the azimuth reference marker, 
all horizontal movements are controlled and 
recorded with the computer controller. The 
azimuth transfer head has been completed 
and is now being tested at the National 
Geodetic Survey of the National Oceanic 
and Atmospheric Administration. 

An AFGL azimuth monitoring experi¬ 
ment is designed to employ the differing 
characteristics of plane mirrors and pris¬ 
matic reflectors for monitoring rotational 
and translational movements of an azimuth 
reference or any other reference station 
whose positional stability must be closely 
monitored to meet Air Force requirements. 
The experiment uses a small He-Ne laser as 
its light source. The light is split and trans¬ 
mitted into two mirrors at the site to be 
monitored. One of these mirrors is a plane 


mirror, the other a prismatic retroreflector. 
Each mirror is so aligned that it will return 
its image of the laser to a positional monitor 
consisting of a silicon diode junction barrier 
capable of monitoring the movement of the 
centroid of the return image in two axes. 
Rotational movements are discriminated 
from translational movements by com¬ 
paring the images reflected from the plane 
mirror and retroreflector. A constant rec¬ 
ord of the fluctuations of the position of the 
centroids of the two returning images is 
recorded on magnetic tape. 

AFGL sponsors a program to develop a 
field device for real time measurement of 
astronomic refraction. The two-color re- 
fractometer measures very precisely the 
differential refraction between the blue and 
red portions of the image of the star. The 
total refraction is calculated from the meas¬ 
ured differential refraction. The next phase 
wiil consist of the de lopment of a small 
scale instrument capable of being taken to 
geodetic survey sites where the two-color 
observations will be used to determine 
astronomic refraction at the point of survey. 

Laser Ranging and Radio Inter¬ 
ferometry: More accurate distance meas¬ 
urements of the moon and high altitude 
artificial satellites made by earth-based 
laser ranging telescopes, and accurate an¬ 
gular measurements made by radio inter¬ 
ferometers, may soon produce significant 
advances in geodesy and geodynamics. 
Measurements accurate to a few centi¬ 
meters will allow us to measure solid-earth 
tides and continental drift, as well as to 
improve our knowledge of variations in the 
earth’s rotation rate and polar motion. 

AFGL participated in the NASA Lunar 
Laser Ranging Experiment. Since 1970, 
more than 2400 range measurements have 
been made between the McDonald Obser¬ 
vatory in Texas and four of the retrore- 
flectors placed on the moon by the Apollo 
and Soviet space missions. AFGL scientists 
have analyzed these data, using the Plan¬ 
etary Ephemeris Program, a large com- 






158 


puter program developed under contract by 
AFGL and other Dot) agencies. The data 
analysis has significantly improved our 
knowledge of: the lunar orbit and its phys¬ 
ical libration, the coordinates of the 
McDonald Observatory, the principal term 
in the earth’s gravity field, and day-to-day 
variations in the earth’s rotation rate. 

AFGL’s analysis of lunar ranging data 
also produced the first verification of the 
Principle of Equivalence for massive bodies, 
the cornerstone of Einstein’s General 
Theory of Relativity. This significant scien¬ 
tific achievement was reported in both 
academic and popular publications. 

The AFGL lunar telescope, operated in 
Arizona between 1968 and 1972, has been 
refurbished by Australian geodesists and is 
now in operation near Canberra. Laser 
ranges from a southern hemisphere obser¬ 
vatory allow analyses of the lunar data for 
separate determinations of variations in the 
earth's rotation and movement of the pole. 

Complementing the lunar ranging ex¬ 
periment is an extensive NASA-DoD pro¬ 
gram for laser ranging to earth satellites, a 
technique pioneered by AFGL scientists in 
the early 1960s. 

The launch of the high-altitude, high- 
mass-density Laser Geodetic Satellite 
(LAGEOS) in 1976 has provided a target 
whose orbit is relatively free from the ef¬ 
fects of atmospheric drag and small-scale 
variations in the earth’s gravity field, allow¬ 
ing range measurements for geodesy ac¬ 
curate to 5 to 10 cm. 

Another technique that has been used for 
geodetic measurements is very-long- 
baseline interferometry (VLBI). VLBI 
determines the three-dimensional position 
of one radio telescope relative to another 
using observations of distant radio sources 
such as quasars. AFGL, together with 
NASA, the National Science Foundation, 
and the National Geodetic Survey, is sup¬ 
porting the development of a very accurate 
VLBI system. Geodetic positions have been 
determined within a few centimeters over 
continental distances and a few millimeters 


over a distance of one kilometer by analyses 
of data already obtained. Variations in earth 
rotation have also been determined from 
VLBI data. 

Many geodetic parameters, such as the 
coordinates of observing stations and the 
earth’s instantaneous pole of rotation, can 
be determined most efficiently by com¬ 
bining several types of data during anal¬ 
yses. The Planetary Ephemeris Program 
will be used by investigators under AFGL 
contract to perform simultaneous least 
squares solutions for a large number of 
parameters, using lunar laser ranging, 
satellite laser ranging, and VLBI data. 

Absolute Gravimetry: The Terrestrial 
Sciences Division’s program in absolute 
gravity is divided into three main areas: 
support of outside research into measure¬ 
ment techniques and of comparative meas¬ 
urements by other absolute instruments; 
the study of the physics of the measurement 
techniques and the development of new in¬ 
strumentation; and measurements in the 
laboratory and at selected field sites with 
the AFGL transportable system. 

The outside work supported by AFGL 
includes that of the Joint Institute for Lab¬ 
oratory Astrophysics in Boulder, Colorado. 
AFGL is supporting the development of a 
novel system for the isolation of a reference 
reflector in an interferometer type of abso¬ 
lute gravity instrument. This system, which 
uses an electro-mechanical feedback system 
to synthesize a very long period vertical 
mass-spring support, is being designed and 
built into a package that will be capable of 
directly supporting the reference reflector 
on a gravity instrument. 

AFGL supported a six week visit by a 
team of Italian scientists who brought with 
them the transportable absolute gravity 
measurement system developed by the Isti- 
tuto di Metrologia “G. Colonetti” of Turin, 
Italy, with the cooperation of the Inter¬ 
national Bureau of Weights and Measures. 
Gravity was measured at six sites: Hanscom 
AFB, Mass.; Denver, Colo.; Holloman 




159 


AFB, N. Mex.; San Francisco, Calif.; 
Bismarck, N. Dak.; and Miami, Fla. The 
system had a mass of about 1500 kg when 
packaged for air transport. The work in¬ 
cluded a final remeasurement at Hanscom 
AFB. The uncertainty obtained was about 
ten parts in a billion at most sites. 

The AFGL instrumentation can make 
quantitative determination of small effects 
on the measured acceleration of gravity. Ef¬ 
fects caused by the gravity gradient and air 
resistance can be removed from the final 
value, using empirical determinations 
rather than theoretical corrections. Knowl¬ 
edge of the physics behind the measurement 
techniques will result in significant im¬ 
provements in future instruments of this 
type. 


GRAVITY RESIDUALS (ANGSTROMS) 
CHAMBER SUSPEN0E0 

» REAL DATA (130 DROP AVERAGES) 



The results of averaging data from 150 drops 
with the chamber on an isolation system. The 
solid line is the result of subjecting synthetic 
data, with a 3 fim/sec'/m gradient included, to 
the same least-squares analysis. Thus, most of 
the systematic appearance, if not all, is caused 
by the vertical gradient. 

AFGL is investigating new developments 
in electronics and other areas to solve some 
of the current problems with this kind of 
instrumentation. Several techniques for 
simplifying system operation are currently 
being employed at AFGL. The system is 
completely automated and data are 
analyzed and corrected for gravity tides in 
real time. Optical and mechanical alignment 
are simplified over previous systems, and 


self-checks on timing accuracy can be per¬ 
formed independent of a gravity meas¬ 
urement. 

Measurements are currently being made 
with a system that incorporates the vacuum 
chamber from the first generation instru¬ 
ment and uses a control system and support 
base (with optics) built at AFGL. The 
method used for measurement is to drop one 
reflector of a two-beam Michelson interfer¬ 
ometer and determine the distance fallen in 
known time intervals by direct meas¬ 
urements of interference fringes. 

The vacuum chamber allows a 60 cm free 
fall path. A smaller vacuum pump is used, 
and the pump magnetic field is reduced con¬ 
siderably from the earlier system. An “old- 
fashioned”, simple, free-fall technique is 
used. The system has a total mass of about 
700 kg when packed for air transport, and it 
is contained in nine boxes that can be 
handled by one or two people. 

The first field measurements were made 
in May 1978, approximately 6 months after 
the decision to convert the old vacuum 
chamber for use with the new system. At 
the time of that field trip, a computation 
technique that used 150 time measurements 
from 3 different positions in the free fall 
path was being usedl This trip was very 
valuable in demonstrating the capabilities of 
the system, and in leading to an improved 
computational technique for data reduction. 

In this new method the time and distance 
data are fit with a least-squares technique to 
the formula for uniform acceleration. The 
results obtained from this least-squares fit 
are: the acceleration of gravity; the initial 
velocity of the dropped reflector and the 
initial position of the dropped reflector; and 
a table of residuals for each drop. The 
residuals for each position in the path can be 
averaged and then plotted as a function of 
position. These residuals represent the de¬ 
viation of the relative path difference be¬ 
tween the reference reflector and the freely 
falling reflector from what it would be if the 
reference reflector were not accelerating at 
all, and the free falling reflector were ac- 





160 


celerating uniformly with the acceleration 
of gravity. The chamber was also isolated 
from the reference reflector and the rest of 
the optics by placing it on a separate vibra¬ 
tion isolation system. 

The most recent value obtained at AFGL 
is: 980378.673+ .007 milligal (one milligal = 
10~ :l cm/sec 2 ). This value is only 0.002 mgal 
different from the average of measurements 
obtained in 1968 and 1969 with the first 
generation AFCRL (Hammond-Faller) sys¬ 
tem. This demonstrates a remarkable sta¬ 
bility in the value of gravity at the Haskell 
Observatory over a ten year period of time. 

Satellite Altimetry: One of the major 
tasks of geodesy is the determination of the 
gravity field over the entire earth. Prior to 
the advent of satellites, global representa¬ 
tion of gravity was severely hampered by 
sparse or poorly distributed gravimetric 
measurements in the oceans. With the 
launching of the GEOS-3 satellite in 1976, 
however, enormous improvements have 
been achieved in our knowledge of the 
ocean’s gravity field. The radar altimeter 
readings from GEOS-3 can be used to 
determine the shape of the ocean’s surface 
with great accuracy, leading to important 
applications not only in geodesy, but also in 
geophysics and oceanography. 

If the earth were all water, right to its 
center, mean sea level would be a simple 
geometrical figure, namely, a spheroid that 
is closely approximated by an ellipsoid of 
revolution. However, the earth is largely 
solid and supports density variations in con¬ 
tinental ajeas and under oceans. These 
density variations cause mean sea level to 
vary by scores of meters from an ideal or 
reference ellipsoid. The irregular, smooth 
surface, called the geoid, formed by the 
extension of mean sea level throughout the 
earth is a fundamental reference surface in 
geodesy. Separations of the geoid above or 
below the reference ellipsoid are dependent 
on the variation of the earth’s gravity field. 
This relationship has been a principal topic 
of investigation by geodesists, who have de¬ 


vised a means for determining the ellipsoid- 
geoid separations from surface gravimetric 
measurements. Now, GEOS-3 satellite alti¬ 
metry can also be used to derive ellipsoid- 
geoid separations and, thus, the gravity 
field over the oceans with great accuracy. 

The GEOS-3 radar altimeter is designed 
to measure the satellite’s distance above sea 
level to a fraction of a meter. If the sat¬ 
ellite’s orbit can be independently estab¬ 
lished with 1 m accuracy, the determination 
of the shape of the mean sea level is a 
straightforward procedure. However, 
standard global tracking nets cannot 
achieve 1 m orbital accuracies, so the high 
precision requires denser nets or other 
advanced schemes. 

At AFGL, the approach to satellite altim¬ 
etry has been to assume that ground track¬ 
ing is only good enough to achieve orbital 
accuracies of about 20 m. If we knew the 
position and velocity of the satellite at any 
epoch and integrated the satellite motion 
over a short arc (less than one quarter of a 
revolution), we could recover the position of 
the satellite to within about 1 m over the 
entire arc. Although the position and veloc¬ 
ity of the satellite on the short arc are not 
known with adequate precision, we can 
refine our knowledge of these quantities by 


ICELAND 



NORTH ATLANTIC GRAVITY ANOMALIES 
FROM GEOS-3 ALTIMETRY 


Perspective diagram of gravity anomaly 
surface in the North Atlantic. Vertical scale is 
greatly exaggerated. 






161 


comparing altitudes from a number of in¬ 
dependent , interlocking short arcs and im¬ 
prove our ability to determine the short 
arcs. Where two short arcs cross, the dif¬ 
ference in measured altitudes to sea level is 
the vertical distance between the two arcs. 
The vertical interorbit ties provide a rather 
tight interlocking of a net of arcs, particu¬ 
larly in the important vertical direction. 
Subtracting the altimeter measurements 
from this net gives, finally, the shajie of the 
ocean surface. To appreciate the magnitude 
of this computational task, one must re¬ 
member that many thousands of GEOS 
tracks are available, containing more than 
one million altimetric values. 

Initial AFGL efforts to exploit GEOS-8 
data produced the computer program 
“Short Arc Reduction of Radar Altimetry" 
(SARRA). Because of the large number of 
measurements available, the North Atlan¬ 
tic and Indian Oceans received particular 
attention. Using only a portion of the avail¬ 
able data (41(> tracks) the SARRA reduction 
showed that geoid heights could be deter¬ 
mined from the altimeter data to an accu¬ 
racy near the meter level. A final version of 
this program was delivered to the Defense 
Mapping Agency Aerospace Center for 
application in operational problems. 

Further research led to the development 
of SAGG (Satellite Altimetry and Ground 
Gravity), which utilizes altimetry aug¬ 
mented by surface gravity measurements 
and leads to a more accurate global solution, 
especially over land areas where altimetry 
cannot be used. 

The most recent research at AFGL has 
led to a further refinement in SAGG, the 
point mass technique. Insertion of point 
masses in areas where detailed gravimetry 
or altimetry already exist can add fine detail 
to a geopotential model based on spherical 
harmonic coefficients. As a result, the short- 
wavelength variations in the geoid can be 
closely examined in a limited area without 
distorting the long-wavelength features. 
Although comparable results might be 
attained by solely utilizing harmonic coeffi¬ 


cients, the point mass approach offers a 
considerable advantage in economy and 
flexibility, an important consideration when 
large amounts of data must be processed. 

A new satellite, SEASAT-1, with an im¬ 
proved altimeter accurate to 10 cm, was 
launched in 1978. SEASAT-1 permits ex¬ 
tension of the altimetry measurements to 72 
degrees north and south latitudes, denser 
global measurements, and increased accu¬ 
racy. Although a power faulure caused 
SEASAT-1 to cease transmitting after sev¬ 
eral months of operation, one global data set 
has been acquired. These data can easily be 
merged with existing G EOS-8 information 
in the short-arc solution so that even higher 
geoid accuracies will be attained. 


GEOID UNDt'iATION CONTOUR! FROM A IRHERICAl HARMONIC (4 DCORtC IOLUTION AND A POINT 
MASS AOJUSTMENT SUPCRlMRQSCO ON THE Oi.O«Ai ADJUSTMENT USING COMBINATIONS OF GRAVITY 
ANOMALY ANO ALTIMETRIC DATA 



IOO* 90* *0* -TO* -BO’ -SO* -40* -SO* -20* 

LONGITUDE (Ml 


REFERENCE FLATTENING I/2M2S 


CONTOUR INTERVAL BO METER! 


Black-bordered rectangle in Atlantic Ocean 
contains grid of inserted point masses. In¬ 
creased short-wavelength detail is evident 
from comparison of contours within and out¬ 
side point mass area. 


Present levels of observational accuracy 
make satellite altimetry much more sensi¬ 
tive to the shape of the earth than gravi¬ 
metry; a 1 m rms geoid height over an area 
of 1 square degree tells much more about 
the shape of the earth than the same square 
with a 8 mgal rms gravity anomaly. Because 











162 


this relative information content applies to 
the description of the earth’s gravity field as 
well, satellite altimetry will make signifi¬ 
cant contributions to gravity mapping. 

Advanced Adjustment Techniques for 
Gravity Field Modeling: Geopotential 
models of regional and of global extent have 
been developed. The simplest approach is 
the standard linear least-squares method, 
which solves for an arbitrarily chosen set of 
parameters (for instance, the coefficients of 
a truncated spherical harmonic expansion) 
from a collection of measurements whose 
relative weights are assigned. Linear least- 
squares methods involving classical integral 
formulas are applicable when homogeneous, 
regularly distributed, and dense data 
coverage is available. With the advent of 
modern techniques for gravity measure¬ 
ments — satellite orbital analyses, satellite 
altimetry, satellite-to-satellite tracking, 
and, eventually, gravity gradiometry — an 
immense amount of information regarding 
the earth's gravity field at different levels is 
provided. However, the data are not uni¬ 
formly distributed over the earth, are 
heterogeneous, and contain errors of 
various types and magnitude. Collocation is 
a refined and sophisticated method to 
handle such complicated problems. 

The least-squares collocation takes into 
account the covariances between the obser¬ 
vations and the cross-covariances between 
the unknowns and the observations. There¬ 
fore, analytical covariance functions must 
be developed. AFGL theoretical and ex¬ 
perimental efforts in this area include: the 
theory and application of least-squares col¬ 
location: the theory and development of co- 
variance functions: and application of col¬ 
location for various combination and gravity 
data-reduetion problems. These include the 
combination of satellite altimetry with air¬ 
borne gradiometry and satellite-to-satellite 
tracking for the recovery of gravity an¬ 
omalies on the surface of the earth. 

Although collocation has a theoretical 
elegance, it is burdened by computational 


difficulties because a pure collocation ad¬ 
justment requires the inversion of a matrix 
of order equal to the number of observa¬ 
tions: a conventional least-squares adjust¬ 
ment requires the inversion of a matrix of 
order equal to the number of unknowns. 
Other generalized least-squares collocation 
models have been investigated and com¬ 
pared with conventional collocation. In 
these techniques the order of the matrix to 
be inverted is equal to the number of un¬ 
knowns instead of to the number of the 
observations. The adjustment is computa¬ 
tionally almost as simple as for ordinary 
least -squares adjustment. 

A priori covariance functions are re¬ 
quired for generalized least-squares ad¬ 
justments (collocation). For this reason, the 
covariance functions of physical geodesy 
have been investigated. In studying the 
morphology of gravity anomaly covariance 
functions, the properties of isotropy, 
harmonicity, and positive definiteness are 
assumed: such functions are conveniently 
specified by three essential parameters: 
variance, correlation distance, and a curva¬ 
ture parameter such as the variance of the 
horizontal gradient. An AFGL contractor 
demonstrated that adopting a spurious 
covariance function has only a relatively 
minor effect in the results of a collocation 
adjustment, but it does have a significant 
effect in changing the estimated accuracies 
of the results. 

Two models were derived for the degree 
variances of global covariance functions and 
they are compatible with a 200 E* horizontal 
gravity gradient variance, (IE = 1 mgal/10 
km) the GEM-9 (Goddard Earth Model 9) 
geopotential coefficients (derived from 
satellite dynamics), and point and mean 
gravity anomaly variances. Bucubic spline 
functions were also used to approximate 
covariance functions to improve the speed of 
collocation adjustments. Anisotropic and 
nonstationary covariance functions have 
also been used for the adjustment and 
prediction of geopotential data. Where 
appropriate, the results of these operations 



163 


are superior to operations assuming iso¬ 
tropic and stationary statistics. Integrals 
for the upward continuation of gravity 
anomaly covariance functions for spherical 
and flat earth formulations have been 
derived. 

Correlations between gravity anomalies 
and other geophysical variables have long 
been used by geophysicists to model the 
earth’s structure from gravity measure¬ 
ments. Recently there has been increasing 
interest in the inverse process: estimating 
gravity anomalies from other geophysical 
observables. Models were derived for the 
cross-covariance functions between topog¬ 
raphy, gravity anomalies, and density 
variations within the earth. No correlation 
was found between gravity anomalies and 
topography on a global scale, but on a scale 
of the order of 5 degrees by 5 degrees, it was 
found that theje are significant correlations 
for 30 percent of the world, mostly over the 
continents. 

Techniques for modeling from terrestrial 
gravity data and satellite dynamics were 
reviewed. Studies were conducted to assess 
the errors due to the disturbing topography 



Geoid profile from SARRA reduction along 
GEOS-3 track in Atlantic Ocean. 


in gravity anomaly downward and upward 
continuation. A mathematical technique 
was developed for the efficient combination 
of various types of physical geodetic data 
into a uniform gravity field model. The 
methodsuses frequency domain techniques. 
Matched asymptotic expansions are used to 
develop improved flat earth approxima¬ 
tions, determine regions of convergence, 
and match global and local gravity models. 

A rigorous theory for the combination of 
airborne gradiometer and accelerometer 
measurements was derived for local and 
regional geopotential models. An accuracy 
and simulation study was performed to de¬ 
termine optimal point and profile configur¬ 
ations from aerial measurements alone and 
in combination with existing satellite altim¬ 
etry data over ocean areas. 

GEOKINETICS 

Improved technology used in the design 
and construction of new Air Force systems 
has spawned increased concern about the 
effects of earth motions (geokinetics) on 
system components. Inertial guidance in¬ 
strumentation is a typical example. Each 
generation of gyros or accelerometers de¬ 
veloped for use in guidance systems exceeds 
the sensitivity of the previous generation by 
an order of magnitude or more. Unfor¬ 
tunately, this enhancement in performance 
increases the sensitivity to geokinetic 
effects, thereby increasing the potential for 
errors caused by the motion environment in 
which the instrument must operate. 

In other instances, the structural re¬ 
sponse of a facility to motion inputs may be 
the principal concern. If the facility must 
provide a relatively stable motion environ¬ 
ment for the instrumentation or operational 
syszem housed in it, then the natural vibra¬ 
tion frequencies of the structure must be 
well outside the bandwidth of significant 
input motions to prevent amplification of 
those motions. 

The apparent solution to problems caused 
by earth motion effects is to develop more 
effective isolation or compensation tech- 



164 


niques. However, complete knowledge of 

the characteristics of the motion environ¬ 
ment and the manner in which this envi¬ 
ronment interacts with system or facility 
performance is needed to do this. The ob¬ 
jective of the geokinetie research and ex¬ 
ploratory development conducted by the 
Terrestrial Sciences Division is to develop 
this knowledge and provide it to system 
designers and engineers. 

Crustal Motion Research: The Terres¬ 
trial Sciences Division conducts a compre¬ 
hensive research program into the causes 
and patterns of earth motions, with em¬ 
phasis on those with present or potential 
future impact on Air Force systems. 
Seismology, geology, and geotectonics are 
studied to predict the spatial and temporal 
properties of motions of the earth’s crust 
over a wide range of frequencies S|)ecific 
efforts include the measurement and inter¬ 
pretation of long-period deformations, the 
modeling of seismic motions with realistic 
geometric and physical properties, and the 
determination of seismic risk to Air Force 
systems and structures. 

A new borehole tiltmeter array was de¬ 
ployed at Maynard, Mass., in early 1975; it 
complements a similar operational array in 
Bedford, Mass., 25 km to the northeast. 
Installation in vertical boreholes minimizes 
the cavity effects that have plagued earlier 
observations made in mines or tunnels. The 
Maynard instruments were emplaced at a 
depth of 120 m in cased holes; the Bedford 
array is at a depth of 20 m in uncased holes. 
Data from both sets of instruments, which 
differ in principle, design, and installation, 
agree within 5 percent at the semi-diurnal 
tidal frequencies, but show little resem¬ 
blance at nontidal periods. A strong annual 
component ranging from 5 to 15 micro¬ 
radians (grad) is present on the shallow 
Bedford instruments, but is not apparent on 
the Maynard instruments at 120 m. Tilt 
steps resulting from teleseisms are not 
present at the 10'" level, in contrast to some 
results reported by others. One Maynard 


instrument, in continuous operation for 3 
years, showed an extraordinarily low 
apparent ground tilt of 0.3grad, although 
repeated geodetic leveling suggests a lesser 
net tilt of O.OSgrad over that interval. 



Borehole Tiltmeter Array Concept. 


Also, a cluster of tiltmeters was emplaced 
at a depth of 3 m at Maynard to compare 
data with those at 120 m and with the data 
from the U.S. Geological Survey network 
straddling the San Andreas Fault in 
California. If satisfactory results could be 
obtained from the shallow’ cluster, consid¬ 
erable cost savings could be realized. 
However, the agreement, both among the 
shallow’ tiltmeters and with the deep tilt- 
meters, was poor over most of the fre¬ 
quency band of interest. The shallow in¬ 
stallation w’as overwhelmed by meteorolog¬ 
ical effects (radiation, temperature, and 
precipitation) and changes in soil proper¬ 
ties. 

A powerful computer processor of 
lengthy time series was developed to 
analyze the tiltmeter data. The processor 
can; accept a multi-channel series with gaps 
and data shifts; apply scale factors; delete 
bad points; solve for linear trends, ocean 
and body tide groups, and correlations; and 
determine tidal ellipse parameters. Con¬ 
siderable progress has also been made in 
analyzing and comparing long-term 
records, using information theory. This 
technique is considerably more flexible than 





165 


conventional least-squares, inasmuch as the 
probability density functions of the data (or 
residuals) do not have to be Gaussian. 
Rather, they may be specified or de¬ 
termined from segments of the time series 
itself. This method might have the potential 
to evoke a fundamental change in data 
analysis in general. 

A 3-year effort began in March 1978 to 
measure long-term tilt and strain in the Yel¬ 
lowstone region of Wyoming and Montana, 
This area is one of moderate seismicity and 
has been postulated to be the surface mani¬ 
festation of an upwelling plume of molten 
material from the earth’s mantle, which 
should be detectable by the effects of its 
anomalous physical properties. A new biax¬ 
ial tiltmeter, suitable for installation in 50-m 
boreholes, has been developed for this 
study. Ten of these, as well as several hori¬ 
zontal laser strainmeters, are being de¬ 
ployed at sites approximately 10 km apart 
and carefully selected to avoid cavity and 
topographic effects or permit their compu¬ 
tation. The earth tides will be analyzed to 
check on the completeness of tidal theory 
and to verify the absence of strain-induced 
tilts. The variations of tilt and strain will be 
interpreted in terms of regional crustal 
structure, tectonics, and seismicity. 

Increased emphasis on seismic wave 
propagation resulted from an earthquake in 
the Pocatello Valley (Idaho) in March 1975. 
The seismic waves from the earthquake 
caused an anomaly in some of the Minute- 
man guidance systems diagnostic para¬ 
meters at Wing V several hundred kilo¬ 
meters away. Only some of the missiles 
were affected, forming a geographic pattern 
that extended through the center of the 
wing from northwest to southeast. A subse¬ 
quent field reconnaissance revealed that the 
missiles sited on plateaus were perturbed, 
while those in the lower-lying valleys were 
not. Normally, ground motion recorded 
from an earthquake of this magnitude at this 
distance would not produce the anomalies 
observed. This suggested that the motions 
were controlled by the geology or topog- 



Borehole Biaxial Tiltmeter. 


raphy, through focusing or some similar en¬ 
hancement mechanism. To investigate this 
possibility, two seismic stations were estab¬ 
lished in geologically contrasting areas 
within Wing V for the purpose of assessing 
ground motion transfer attributes peculiar 
to the area. The stations were in operation 
over the course of a year and recorded both 
earthquake and explosive teleseismic 
events. A contract research effort was initi¬ 
ated to numerically predict the ground 
motions at various locations within the 
wing. The earthquake source was repre¬ 
sented by an equivalent elastic source, and 
the motions were propagated over the 
region using a three-dimensional finite dif¬ 
ference model. It was necessary to program 
the problem for the ILLIAC parallel pro¬ 
cessor computer, because of the number of 
computations required. This technique is 
being extended so that it can be used to 



166 


predict motions from any earthquake or 
nuclear surface burst in the western United 
States. 

In cooperation with AFOSR, a contrac¬ 
tual study was made of the seismicity and 
seismic risk of the central United States, 
the northern Rocky Mountains, and 
Southern California in relation to the re¬ 
gional tectonics. Again with AFOSR, work 
has continued on the development of three- 
dimensional finite element models for the 
simulation of seismic effects on Air Force 
facilities. Improvements have been made to 
earlier computer codes to include damping 
and to minimize model boundary effects. 


Missile Geophysics: In 1976 a silo 
motion study was conducted in a Minuteman 
test silo at Hill AFB, Utah. This study was 
designed to characterize the motion envi¬ 
ronment of the silo and identify those 
motions that introduce alignment and per¬ 
formance errors into the guidance system. 
The 1976 study was a follow-on to a 1974 
study using the latest (Wing V-configured) 
Minuteman missile and suspension system 
without a reentry vehicle. 

Again, the study was split into a seismic 
experiment and an azimuth alignment ex¬ 
periment. The seismic experiment was con¬ 
cerned principally with motions with 
periods of less than 1 minute, while the 
alignment experiment dealt with motion 
periods exceeding 1 hour. Measurements 
were made under ambient conditions as well 
as during selected maintenance activities 
and during two large, distant earthquakes. 

The seismic experiment employed arrays 
of horizontal and vertical seismometers and 
tiltmeters located on the missile, in the silo, 
and in the ground surrounding the silo. 
Results from the seismic experiment indi¬ 
cate that for an event-free, midcontinental, 
rural, seismic environment, the missile roll 
can be modeled as a Rayleigh process which 
roll is caused primarily by air circulation in 
the launch tube from the air conditioning 
system. Due to larger airflow in the silos, 


missiles in other wings could be expected to 
exhibit roll motions up to 2 to 4 times that 
found during this experiment. 

The alignment experiment employed an 
AFGL-developed Automated Azimuth 
Measuring System (AAMS) (described in 
the previous Report on Research) to meas¬ 
ure the long period tilt and rotational 
motions of the silo, the missile skin, and the 
inertial guidance platform. Since tempera¬ 
ture fluctuations induce tilts in both the silo 
and the AAMS instrumentation, tempera¬ 
ture measurements were also made at 
selected points in the silo and near the 
AAMS instrumentation bench. 

Analyses of the alignment experiment 
data were performed in three steps. The 
first step was to estimate the azimuth 
accuracy of the AAMS in the silo environ¬ 
ment. A model of expected behavior of the 
entire AAMS was developed and verified 
using multiple regression analyses of the 
data for two intervals of several days dur¬ 
ation. The second step was to determine the 
motion levels of the silo and missile from the 
AAMS tilt and azimuth measurements. The 
final step was to compare the measurements 
of long-period missile roll with the missile’s 
own estimate of its azimuthal orientation, as 
indicated by the inertial performance data 
from the on-board computer. 

Analyses of the data from the two test 
intervals showed good agreement with the 
theoretical model. Approximately 90 per¬ 
cent of the raw inertial azimuth variations of 
the AAMS were accounted for by the geo- 
kinetic model variables. In addition, the em¬ 
pirically determined coefficients agreed 
closely with the theoretical coefficients. 
Tilts on the silo collimator bench of over 5 
arc sec were seen, and they had a high cor¬ 
relation with small changes in the ambient 
silo air temperature. Missile rotations of up 
to 5 arc sec of azimuth were measured by the 
AAMS during events as well as during a 
2-day quiescent interval when the silo was 
completely sealed. Generally, missile ro¬ 
tations that were not directly related to 
specific events appeared to be related to 



167 


small fluctuations in the silo ambient air 
temperature. Rotations of the missile, 
which is the azimuth reference for Minute- 
man III, were not evident in the guidance 
system’s inertial performance data. 



Automated Azimuth Measuring System 
(AAMS) 


Recent Minuteman guidance improve¬ 
ment programs have made inertial per¬ 
formance data available from several opera¬ 
tional missile wings. Inertial performance 
data from nearly all wings are expected to 
become available within the next year as the 
guidance improvement programs are com¬ 
pleted. These data will provide an expanded 
data b*ise for evaluating the effects of long- 
period geophysical motions on Minuteman 
guidance systems. Analyses of the spatial 
and temporal characteristics of limited seg¬ 
ments of data have already begun. The re¬ 
sults are being compared with other geo¬ 
physical motion data in the respective areas 
and time periods to evaluate correlations 
between the motion data and guidance sys¬ 
tem anomalies. Studies will continue as 
more data become available. 

As improved generations of inertial guid¬ 
ance systems are developed, the need for a 
portable, accurate azimuth standard that 
can evaluate geokinetic effects on a variety 
of azimuth references is apparent. To sat¬ 
isfy this need, a 2-year program is in prog¬ 


ress to improve the azimuth accuracy, relia¬ 
bility, and automation of the Automated 
Azimuth Measuring System. The objective 
of this improvement program is to achieve a 
fully automated system with an accuracy of 
1 arc sec (one standard deviation) over an 
integration period of 1 hour. 

Unique to the AAMS are highly sensitive 
tiltmeters that are being installed in the 
inertial measuring units. By directly mea¬ 
suring tilts and tilt rates across the sensitive 
axes of the inertial gyrocompasses and re¬ 
moving the effects of high frequency 
motion-induced errors, a much-improved 
azimuth estimate should be possible. The 
approach differs from other inertial mea¬ 
surement systems in that it corrects for the 
effects of environmental motions instead of 
attempting to stabilize the measurement 
device in the motion environment. 

SPECIAL STUDIES 

The Division conducted numerous special 
studies for other Air Force agencies to eval¬ 
uate the effects of ground and acoustically 
induced motions on systems and facilities. 

In support of the Missile-X (MX) weapons 
system, a 2-month seismic study was 
conducted at the Defense Nuclear Agency’s 
CASINO facility in Maryland. The study 
was designed to isolate radiation effects 
from seismic side effects generated during 
simulated electrical and mechanical com¬ 
ponent hardening tests of Third Generation 
Gyros. The study addressed itself exclu¬ 
sively to the nature of the seismic motions 
within the CASINO exposure cell excited 
by the test radiation shots. Seismic contri¬ 
butions for each individual test were delin¬ 
eated and their possible effect on the gyros 
considered. 

In the spring and summer of 1978, the 
Division participated in the MISERS 
BLUFF II Explosion Program in western 
Arizona. Although the principal purpose of 
this program was the simulation of near¬ 
source effects due to close-surface nuclear 
explosions, AFGL’s purpose was to deter¬ 
mine ground transmission and local load 



168 


characteristics for both near and far do¬ 
mains in support of the MX program. 
Seismic, tilt, and pressure sensor arrays 
were established near Parker, Arizona, 
some 35 km from a high explosive simulated 
nuclear source of 100 and 600 tons equiv¬ 
alent weight. In addition to the high explo¬ 
sive source, both train and truck sources 
were monitored for establishing a data base 
for future design criteria. 

Also in 1978, in continued support of the 
SAMSO MX program, the ambient motion 
environment in the southwestern United 
States was surveyed in the Basin and Range 
geologic province. The MX, if deployed, will 
be sited in this region. Besides characteriz¬ 
ing the observed and theoretical nature of 
the ambient motions in the area, ground 
intensity level determinations, formulated 
in terms of displacement and acceleration, 
were computed and compared with con¬ 
tinental and worldwide averages. These 
considerations have import to hostile detec¬ 
tion scenarios. Two follow-on studies in MX 
position location uncertainty will be con¬ 
ducted by the Division early in 1979 at 
Vandenberg AFB and the Nevada Engi¬ 
neering Test Bed. 

The Division is also providing consulting 
services to the SAMSO-sponsored Space 
Transportation System Space Shuttle Pro¬ 
gram. A special study was conducted in 1977 
to establish expected motion levels from 
future Space Transportation System 
launches. The results are being used for the 
engineering definition of vibration effects on 
existing and new facilities that will be sub¬ 
jected to extreme acoustic and ground 
vibration levels during a launch. Ground 
motions were first modeled using three- 
dimensional computer simulation algo¬ 
rithms. These algorithms generated the 
ground response of the local geologic envi¬ 
ronment due to impulse pad loads and 
acoustic loading of the models. The models 
were then field verified using missile launch 
data as well as that from high explosive 
sources within the Vandenberg AFB Space 
Transportation System launch complex. 



Stand Alone Seismic Acquisition System, used 
for Special Studies. 


Follow-on studies are programmed for 
1979 to evaluate the vibro-acoustic effects 
on modified facility designs. These studies 
will provide data necessary to design for 
shock isolation of launch control and payload 
preparation facilities. 


JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 


Bliamptis, E. E. 

Rights to Sunshine 

Appl. Opt., Vol. 15(August 1976) 

C ABAMISS, G. H., and Me CONNELL, R. K., 
J R. (Boston Coll., Chestnut Hill. Mass.) 

Tidal Tilt from Tim Borehole Tiltmeter Arrays in 
Eastern Massachusetts 

EOS Trans, of Am. Geophys. Union Vol. 58, No. 6 
(June 1977) 

Eckhardt, D. H. 

Surveying and Geophyscial Measurements with 
Inertial Rotation Sensors 
Proc., Laser Inertial Rotation Sensors, SPIE 22nd 
Ann. Tech. Symp., San Diego, Calif., Vol. 157(31 
August 1978) 

Eckhardt, D. H., and Hadgigeorge, G. 

GEOS--I Altimetry Reductions in the Australia-New 
Zealand Region 

Space Res., Vol. 18, Pergamon Press, N.Y. (1978) 




169 


HaDGIGEORGE, G., and BLAHA, G. (DBASya., 
Inc., Melbourne, Fla.) 

Grarity Fieid Determination from Combination of 
Altimetric and Graeity Anomaly Data 
Proc., 2nd Inti. Symp., Use of Artificial Sate!, for 
Geod. and Geodyn., Lagonissi, Greece (May 1978) 

H.ADGIGEORGE, G., and TROTTER, J. (DBA 
Sys., Inc., Melbourne, Fla.) 

Shoil Arc Reductions of GEOS-.l Altimetric Data 
Geophys. Res. Ltrs., Vol. 4, No. 6 (June 1977) 

Hammond, J. A. 

AFGL Absolute Graeity System 

Proc., Inti. Conf. on Non-Tidal Variations in Gravity, 

Trieste, Italy (June 1977) 

Hammond, J. A., and Iliff, R. L. 

The AFGl. Absolute Graeity Program 

Proc. of Inti. Symp. on Geod. Appl. to Geodyn., Ohio 

State Univ., Columbus, Ohio (2-6 October 1978) 

King, R. W. Counselman, C. C„ III, and 

SHAPIRO, I. I. (Mass. Inst. ofTechnol.) 

I’nicersnl Time: Results from Lunar Laser Ranging 
J. of Geophys., Vol. 82, No. B7 (10 July 1978) 

King, R. W., Shapiro 1.1., and 
Counselman. C. C. Ill (Mass. Inst, of 

Technol.) 

Lunar Dynamics and Selenodesy: Results tram 

Analysis at VLSI and Laser Data 

J. of Geophys. Res., Vol. 81, No. 25 (10 December 1976) 

Lewcowicz, J. F., Me Connell, R. K.. 

Jr. (Boston Coll., Chestnut Hill, Mass.), and 

Cabaniss, G. H. 

Preliminary Results tram a Shallow fiorehole 

TUtineter Array in Massachusetts 

EOS Trans. Am. Geophys. Union, Vol. 58, No. 6 (June 

1977) 

Me Connell, R. K., Jr. (BostonCoil.. 
Chestnut Hill, Mass,)and CABANISS, G. H. 

On the Resolution of Crustal Deformation from Deep 
Borehole Tilt meter Arrays 

EOS Trans. Am. Geophys. Union, Vol. 58, No. 6 (June 
1977) 

Settle, M., IstLt. 

Thermal Power Output gt Explosive Volcanic 
Eruptions 

J. of Volcanology and Geothermal Res., EwsevierPub. 
Co., The Netherlands, Vol. 3, No. 3/4 (May 1978) 

Thomson, K. C., and Doherty, R. <rda, 

Bedford, Mass.) 

Ltr. to Ed., A Correction to “Elastodynamic Near- 
Field pt a Fin ite Propagating Tensile Fa u It by Haskell 
and Thomson” 

Bull. ofSeismolog. Soc. of Am., Vol. 67, No. 4 (August 
1977) 

Comment on “Elastodynamic Near Field of a Finite 
Propagating Transverse Shear Fault by Ker C. 
Thomson and N. A. Haskell" 

J.ofGeophys. Res., Vol. 83, No. B2(10February 1978) 


WlRTANEN, T. E. 

Automation and Geodesy 

J. of Fedn. of New Eng. Surveying Assoc., Vol. 2, No. 
2 (August 1976) 

Earth Science Technologies Association and Satellite 
Geodesy, 1961-1977 

J. of Earth Sci. Technol. Assoc., Vol. 13, No. 3 (15 
September 1977) 


PAPERS PRESENTED AT MEETINGS 
JULY 1976 - DECEMBER 1978 


Anthony, D. 

Long Period Azimuth Variations in a Minuteman 
Missile Silo 

Am. Geophys. Union 1977 Fall Mtg., San Francisco, 
Calif. (5-9 December 1977) 

Cabaniss, G. H. 

The Measu rement of Long Period and Secular Crustal 
Deformation with Borehole Tiltmeters 
Inti. Symp. onGoed. Appl. to Geodyn. (GE0P9), Ohio 
State Univ., Columbus, Ohio (2-6October 1978) 

Cabaniss, G. H., and Me Connell, R. K., 
Jr. 

(Weston Obsv., Boston Coll., Weston, Mass.) 

Tidal Tilt from Two Borehole Tiltmeter Arrays in 
Eastern Mass. 

Am. Geophys. Union Spring Mtg.. Wash., D. C. (30 
May-3 June 1977) 

Cappallo, R. J. , Counselman, C. C. , III, 

SHAPIRO, I. I. (Dept, of Earth and Planet. Sci., 
Mass. Inst ofTechnol.), and KING, R. W., CAPT. 
Numerical Model of the Moon's Rotation 
Am. Geophys. Union Spring Ann. Mtg., Wash., D. C. 
(30 May-3 June 1977) 

Crowley, F., and Ossing, H. 

On Motion Environment 

AIAA Guid. and Control Conf., San Diego, Calif. (16- 
18 August 1976; 

Eckhardt, D. H. 

AFGL Lunar Libration Tables 

XVI Gen. Assbly., Inti. Astronom. Union, Grenoble, 

Fr, (24 August - 2 September 1976) 

Surveying and Geophysical Measurements with 
Intertial Rotation Sensors 

SPIE 22nd Ann. Tech. Symp., San Diego, Calif. (28-31 
August 1978) 

Eckhardt, D. H., and Hadgigeorge, G. 

GEOS-S Altimetry Reduction in the Australia-New 
Zealand Region 

20th Ann. Comm, on Space Res. (COSPAR) Plen. 
Session, Wkg. Gp. 1 Open Mtg., Tel-Aviv, Isr. (13-18 
June 1977) 



HADGIGEORGE, G., and BLAHA, G. (Nova 
Univ., Ft. Lauderdale, Fla.) 

Combination of Satellite Altimetric Data and Gravity 
Anomaly Data 

Am. Geophys. Union 1977 Fall Mtg., San Francisco, 
Calif. (5-9 December 1977) 

Grarity Field Determination from Combination of 
Altimetric and Gravity Anomaly Data 
2nd Inti. Symp. on The Use of Artificial Satel. forGeod. 
and Geodyn., Lagonissi, Greece (27 May - 3 June 1978) 

HADGIGEORGE, G., and ROONEY, T. P. 
GEOS-d Altimetry Reduction in the North Atlantic 
Region 

Mtg. of GEOS-3 Principal Investigators, New Orleans, 
La. (15-18 November 1977) 

Hammond, J. A. 

AFGL Absolute Grarity System 

Inti. Symp. on Non-Tidal Variations in Gravity, 

Trieste, Italy (20-24 June 1977). 

Hammond, J. A., and Iliff, R. L. 

The AFGL Absolute Grarity Program 

Inti. Gravity Comsn., Paris, Fr. (11-16 September 

1978) 

Inti. Symp. onGeod. Appl. to Geodyn. (GE0P9), Ohio 
State Univ., Columbus, Ohio (2-6 October 1978) 

King, R. W.,Capt. 

Improved Value of the Earth's Gravitational 
Constant trow Analysis of LunarLaserRanging Data 
AF Sys. Command Sci. and Engrg. Symp., Wright- 
Patterson AFB, Ohio (26-28October 1977) 

King, R. W. andCoUNSELMAN, C. C., Ill, 
SHAPIRO, I. I. (Mass. Inst. ofTechnol.) 

Geodetic Results from Lunar Laser Ranging 
Am. Geophys. Union 1977 Spring Mtg., Wash., D. C. 
(30 May - 3 June 1977) 

Lewkowicz, J. F., McConnell, R. K., 

J R. (Weston Obs v. .Boston Coll., Weston, Mass.), and 

Cabaniss, G. H. 

Prel im ina ry Resultsfrom Shallow Borehole T iltmeler 
Army in Massachusetts 

Am. Geophys. Union Spring Mtg., Wash., D. C. (30 
May-3 June 1977) 

McConnell, R. K., Jr. (Weston Obsv Boston 
Coll., Weston, Mass.)j and CABANISS, G. H. 

On the Resolution of Crustal Deformation from Deep 
Borehole Tiltweters 

Am. Geophys. Union Spring Mtg., Wash., D. C. (30 
May-3 June 1977) 

Reasenberg, R. D., Goldstein, R. B., 
Mac Neil, P. E. , Shapiro, 1.1. (Mass inst. of 
Technol.), and KING, R. W. 

The Pole Direction and Precession at Mars 
Am. Astronom. Assoc. Div. of Planet. Sci., Boston, 
Mass (25-30 October 1977) 


SCHNELZER, G. A., ANTHONY, D., and 
Cabaniss, G. H. 

Azimuth Alignment Experiment 

AIAA Guid. and Control Conf., San Diego, Calif. (16- 

18 August 1976) 

Shearer, J. A., Capt., and Atw-ill, W. D. 

(Trustees of Boston Coll., Chestnut Hill, Mass.) 
Description and Applications for an Automated 
Inertial Azimuth Measuring System 
AIAA Guid. and Control Conf., Palo Alto, Calif. (7-9 
AuUST ‘'k&V-( 

SZABO, B. 

Geodetic and G' uphysical Research and Development 
at AFGL 

Second Air Force MX G & G Conf., St. Louis, Missouri 
<l2-i< \pril 1978) 


TECHNICAL REPORTS 
JULY 1976 - DECEMBER 1978 


Anthony, D., et al 

Earth Mot ions a ml Their Effects on Air Force Systems 

AFGL-TR-7S-0141 

(July 1976) 

Cabaniss, G. H. 

SiloTiltan I Azimuth Motion Study, Whiteman AFB. 
Missouri t April-June 197ti) 

AFGL-TM4U2 May 1977) 

Crowley, F., and Hartnett, E. (Boston 

Coll./Weston Obsv., Weston, Mass.) 

Roll Attributes of a Miuuteman Wing V' Missile in a 
Benign, Prelaunch, Seismic Environment 
AFGL-TR-78-0016 (January 1978) 

Crowley, F., Hartnett, E. (Boston Coll./ 
Weston Obsv., Weston, Mass.), and OSSING, H. 
Ground Vibration Level Estimates tor Space 
Transportation System La/inches at Vandenberg AFB 
AFGL-TR-77-0083 (28 March 1977) 

HADGIGEORGE, G. 

Short Arc Reduction of Radar Altimetry Computer 
Program 

AFGL-TR-77-0170 (January 1978) 

HADGIGEORGE, G., and BLAHA, G. (DBA Sys., 
Inc., Melbourne, Fla.) 

Combination of Satellite Altimetric Data in the Short 
Arc Mode and Gravity Anomaly Data 
AFGL-TR-77-0133 (3 June 1977) 

HARTNETT, E. (BostonColl./WestonObsv., 
Weston, Mass.)and CROWLEY, F. 

Pseudo Velocity Spectral Estimates for Space Shuttle 
Launches at Vandenberg AFB 
AFGL-TM- #3(1977) 



171 


MOLINEUX, C. E., WlRTANEN, T. E.,and 
Gray, R. A. 

Terrestrial Effects on Air Force Operations 
AFGL-TR-764)185 (August 1976) 

OSSING, H. 

A Motion Level Survey - AFGLILC Shaker Facility 
AFGL-TM-# 11 (1978) 

Ossing, H., and Crowley, F. 

Wing V Ground Motion Study 
AFGL-TR-78-0277 (15 November 1978) 

Ossing, H., and Gray, R. 

A Suri'ey of the Ambient Motion Environment in the 
Southwestern Vnited States 
AFGL-TR-78-0052 (28 February 1978) 

Shearer, J. A., Capt., and Anthony, D. 

Long Period Azim uthal Motio n Effects on Minuterna n 
Upgrade Missiles 
AFGL-TR-78-012X (1978) 

Thomson, K. C. 

Terrestrial Effects on Air Force Operations 
AFGL-TR-76AI185 (10 August 1976) 


CONTRACTOR JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 


BLAHA, G. (DBA Sys., Inc., Melbourne, Fla.) 

A Fetc Basic Principles and Techniques of Array 
Algebra 

Bull. Geod.,Vol. 51 (1977) 

Least Squares Prediction and Filtering in any 
Dimensions Using the Principles of Array Algebra 
Bull. Geod., Vol. 51 (1977) 

Refinement of the Short Arc Satellite Altimetry 

Adjustment Model 

Bull. Geod., Vol. 51(1977) 

Accurate Formula Expressing the Difference between 
the Normal Gravity and its Radial Component 
Bull. Geod., Vol. 52 (1978) 

An Accurate Noniterative Algorithm for Computing 
the Length of the Position Vector to a Subsatellite Poim 
Bull. Geod M Vol. 52 (1978) 

GlESE, R. F. (The Res. Fdn., State Univ. of N.Y., 
Albany, N.Y.) 

Hydroxyl Orientations in Gibbsite and Bayerite 
Acta Crystallographies, Vol. B32 (1976) 

HELLER, W. G. (The Anal. Sci. Corp., Reading, 
Mass.) 

Developments in Moving Base Gradiometry 
Proc., Inti. Gravity Comsn., Paris, Fr. (11-16 
September 1978) 


JORDAN, S. K. (The Anal. Sci. Corp., Reading, 

Mass.) 

Statistical Model for Gravity Topography , and 
Density Contrasts in the Earth 
J. ofGeophys. Res., Vol. 83 (1978) 

MERTZ, B., and MARCIELLO, A. A. 

(6585th Test Group, Holloman AFB, New Mex.) 

A Unique Design for Active Control of a Test Pad 
AIAA Paper No. 77-1048 (8 August 1977) 

MORITZ, H. (The Ohio State Univ.) 

Integral Formulas and Collocation 
Manuscripts Geodaetica, Vol. 1 (1976) 

RAPP, R. H. (The Ohio State Univ.) 

The Relationship Between Mean Anomaly Block Sizes 
and Spherica' Harmonic Representations 
J. ofGeophys. Res., Vol. &3(1977) 

Detennimtion of Potential Coefficients to Degree 52 
from 5° Mean Gravity Anomalies 
Bull. Geod., Vol. 51 (1977) 

GEOS-J Data Processing for the Recovery of Geoid 
Undulations and Gravity Anomalies 
J. ofGeophys. Res., Vol. 82(1978) 

RUMMELL, R. (The Ohio State Univ.) 

A Model Comparison in Least-Squares Collocation in 

Physical Geodesy 

Bull. Geod., Vol. 50(1976) 

RUMMELL, R., and RAPP, R. H. (The Ohio 
State Univ.) 

The Influence of the Atmosphere on Geoid and 
Potential Coefficient Determinations from Gravity 
Data 

J. ofGeophys. Res., Vol. 81(1976) 


CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 - DECEMBER 1978 


AMEb, C. B., Clark, R. B., La Hue, P. M., 

and PETERSON, R. W. (Hughes Aircraft Co., 
Malibu, Calif.) 

Rotating Gravity Gradiometer Development 
Vol. I, AFGL-TR-77-0098U) (April 1977) 

Rotating Grarity Gradiometer Development. Volume 
J: Analysis of the Requirements for a Gravity 
Gradiometer Platform 
AFGL-TR-77-0098(II) (April 1977) 

ARCHAMBEAU, C. B. (The Regents of Univ. of 
Colo., Boulder,Colo.) 

Investigations of Tectonic Stress 
AFGL-TR-77-0104 (26 April 1977) 




172 


ATWELL. W. C. , T -istces of Boston Coll., 
Chestnut Hill, Mass i 

Rvmiirh on an Auto n 1 1nrtiiul Azimuth 
Mt’asn rintf System 

AF(JL-TR-7S-()285U November 1978) 

RLAHA, G. (DBA Sys., Imp., Melbourne. Fla.) 
Refinements in the Combined Adjustment of Satellite 
Altimetry and (irarity Anomaly Data 
AFGL-TR-77-01li9 (July 1977) 

The Least-Squares CoUoeat ’nm from the Adjustment 
Point at View and Related To/nes 
A FG L-TR-7*MM)7H (March I97f>) 

BRAMMER, R. F., LeScHACK, A. 
Ofenstein, W. t. 

The Anai. Sei. Corp., Reading, Mass.) 

Gravity Data Evaluation Analysis ami the I'i 
'/.era Definition at the Pliysival Geodesy Systeu 
A FGL-tR-78-l) 188 CIO April 197M) 

C.AITALLO, R.. Coi’NSELMAN <\ 0. Ill, 
Shapiro, 1.1., and Kino, R. w. (Mass. inst. <>f 

Techno).) 

A Numerical Mistet at the Moan's Rotation 

AFGL-TR-77-0178 <2r>July 1977) 

CARTER, N. (State llniv. of N.Y. at Stony Brook) 
Meehanieal Propciiics at Granular Silicates at Depth 
AFGL-TR-7ti-018:i(l August 197(1) 

[)E Bra. 0. B.. and PKLKA, K, .1. (Stanford 
I'niv., Calif.) 

Study to Develop Grailiomctcr Compensation 
Teehnigncs 

AFGI.-TR-77 (HUS(December 197(1) 

KRUCH, I). C., andCl’RRAN, I). R. 

(Stanford Res. Inst., Menlo I'k., Calif.) 
Three-Dimensional Seism le Mmlcliny 
AFC.I,-TR-7(M12ir» (August 197(1) 

GlESE, R. F. (The Res. Kdn., State I'niv. of N.Y., 
Albany, N.Y.) 

Crystallographic St allies 
A FGL-TR 7(1-02(1-1 (October 197(1) 

Ha.IEEA, I). P. (The Ohio State l'ni\.) 

Im pm red Procedures tor the Recovery ot.T Mean 
Grant a Anomalies tram A TS-ttlGEOS-l Satellite to 
Satellite Range-Rate <thserrations l 'siay Least 
Squares Collaration 
AFGL-TR-7K-02HO (September 197k) 

Recovery ot T at Mean (Irarity Anomalies in Local 
Arms tram A TS-tilGEOS-l Satellite to Satellite 
Ranye-Rate Obsecrations 
A FGL-TR-77-0272 (September 1977) 

Handin, J., Friedman, M., and Johnson, 

C. B. (Texas A&M Univ.) 

Study Evaluate, Measure, and Calculate the Thermal 
Cracking of Rocks 
AFGL-TR-77-0122(May 1977) 


HARTNETT, E. B. (Boston Coll., Weston Obsv., 
Weston, Mass.) 

A Simulation Study of a Twelve Degree of Freedom 
S ystem 

AFGL-TR-77-0061 (March 1977) 

HELLER, W. G. (The Anal. Sci.Corp., Reading, 
Mass.) 

E rmr Models for Prototype Moving-Ruse Gravity 
G radiometers 

AFGL-TR-77-0W1 CIO April 1977) 

Heller, W, G., Tait, K. S., and Thomas, 

S. W, (The Anal. Sci. Corp., Reading, mass.) 

Geofast - A Fast Gravimetric Estimation Algorithm 

AFGL-TR-77-0195 (25 August 1977) 

JEFFERIES, J. T. (Univ. of Hawaii, Honolulu, 
Haw.) 

Automata Angulation Study 

AFGL-TR-78-0149(2:t August 1978) 

JEKELI, C. (The Ohio State Univ.) 

An Investigation of Two Models for the Degree 
Variances of Globa I Covariance Functions 
AFGL-TR-78-02H5 (September 1978) 

JORDAN, S. K. (The Anal. Sci. Corp., Reading, 
Mass.) 

Fourier Physical Gemlesy 

AFGL-TR-78-0056 (March 1978) 

Kaula, W. M., Cherubini, G., 
BuRKHARD, N., and Jackson, D. D. (Univ. of 
Calif, at Los Angeles, Calif.) 

Applications of Inversion Theory to New Satellite 
Systems for Determination of the Gravity Field 
AFGL-TR-78-0073 (January 1978) 

KEARSLEY, W. (The Ohio State Univ.) 

Non-Slat ionary Estimation in Gravity Prediction 
Problems 

AFGL-TR-77-0186 (July 1977) 

The Estimation of Mean Gravity Anomalies at Sea 
from Other Geophysical Phenomena 
AFGL-TR-78-0069 (December 1977) 

KELLER, G. V. (Colo. Sch. ofMines,Golden,Colo.) 
Research on the Use of Induced Polarization 
Measurements to Study the Mechanical Properties of 
Unconsolidated Materials 
AFGL-TR-77-0050(May 1977) 

Kovach, R. L., and Israel, M. (Stanford 
Univ., Calif.) 

Near Field Patterns of Seismic Radiation 

AFGL-TR-77-0117 (31 May 1977) 

LEWKOWICZ, J., and McCONNELL, R, K., 
JR, (WestonObsv., Boston Coll., Weston, Mass ) 
Preliminary Results from a Shallow Borehole Till 
Army 

AFGL-TR-77-0168 (March 1977) 




173 


Madden, T. R., and Williams, E. (Maas. 

Inst, of Teehnol.) 

NearSu rface Electrical Properties of Rocks ns a Guide 
to Mechanical Properties 
AFGL-TR-76-0305 (December 1976) 

MARSON, I., and ALASIA, F.Unst. di Metrol. “G. 
Colonetti”, Natl. Res. Council. Turin, Italy) 

Absolute Grnrity Measurements in the I ’nited States 
ol America 

AFGL-TR-78-0126(May 1978) 

Me Connell, R. K., Jr. and Lewkowicz, 

J. (Weston Obsv., Boston Coll., Weston, Mass.) 
Research on the Suture of Ground Tilts in the Period 
Ramie UP to III 7 Seconds 
AFGL-TR-78-0105121 April 1978) 

MELCHIOR, P. (Royal Obsv. of Belgium, Brussels. 
Belg.) 

Trans World Tidal Grnrity Protile 
AFGL-TR-77-0037 (December 1976) 

Merchant, H. ('., and Hcggett, G. R. 

(I'niversity of Wash.) 

Stabilized LaserGrariineter 
AFGL-TR-76-0275 (November 1976) 

Moritz, H. (The Ohio State Univ.) 

Cocaria nee Fit net ions in Least-Squares C allocation 
AFGL-TR-76-016T) (June 1976) 

Least-Squares Collocation as a Gradational In rente 
Problem 

A FG I, -TR -76-0278 (November 1976) 

On the Computation at a Global Coucariance Miulel 
AFGL-TR-77-0163 (July 1977) 

Recent Oecelopnients in the Geodetic Boundary-Value 
Problem 

AFGL-TR-78-0002 (December 1977) 

Statistical Eon mint ions of Col load ion 
AFGL-TR-78-0182 (June 1978) 

The <)perational Approach to Physical Geodesy 
A FG L-TR-78-0281 (October 1978) 

MORSE, E. P. (Wellesley Instr. Corp., Waltham, 
Mass.) 

A Dual Electro-Optical Liylit Image Receierrand 
Recorder 

AFGL-TR 77-0002 (January 1977) 

MURPHY, A. J. (Lamont-Doherty Geol. Obsv. of 
Columbia Univ., Palisades, N.Y.) 

Plate Tectonics and the Discrimination of 
Cnderground Explosions from Earthquakes 
AFGL-TR-77-0106 (April 1977) 

Nuttli, O. W., SoGc Kim, Hufi-Yuin 

Wen, and WAGNER, J. A. (St. Louis Univ., Mo.) 
Research in Seismology: Earthquake Magnitudes 
AFGL-T R-76-0238 <11 October 1976) 

PEARLMAN, M. R. (Smithsonian Astrophys. 
Obsv., Cambridge, Mass.) 

Coo/iemtire Laser Ranging Research Program 
AFGL-TR-77-0140 (May 1977) 


PELKA, E. J., and DE BRA, D. B. (Stanford 

Univ., Calif.) 

Study to Derelop Gmdioineter Techniques 
AFGL-TR-76-0297 (June 1977) 

PERSEN, L. N. (Inst, of Appl. Mech., Univ. of 
Trondheim, Norway) 

Ex/ieri mental Study of a Titn net's Collapse Criterion 
AFGL-TR-77-0069 (31 January 1977) 

On Shock Wore* in Rock Created by Surface- and 
Sea r-to-Su rface Detonations 
AFGL-TR-77-0070 (31 January 1977) 

The Application of Theoretical Results in the Design of 
Safe Shelters in Rock 
AFGL-TR-77-0071 (31 January 1977) 

RAPP, R. H, (The Ohio State Univ.) 

The l ’se of Grnrity Anomalies on a Bounding Sphere 
to lntprore Potential Coefficient Determinations 
A FG L-TR-77-0146 (June 1977) 

A Global 1°. Y 1 ° Anomaly Field Combining Satellite, 
GEOS-.t Altimeter and Terrestrial Anomaly Data 
A FGL-TR-78-0282 (September 1978) 

Rol'FOSSE, M. C. (Smithsonian Inst., Astrophys. 
Obsv., Cambridge, Mass.) 

In rest igat ions of the Long-Wavelength Grnrity Field 
of the Oceans 

AFGL-TR-78-0271 (October 1978) 

RUMMELL, R. (TheOhio State Univ.) 

A Model Com/strison in Least Squares Collocation 
AFGL-TR-76-0198 (August 1976) 

Rummell, R.. Hajela, D. P., and Rapp, R. 

H. (The Ohio State Univ.) 

Recorery of Mean Gravity Anomalies from Satellite- 
Satellite Range Rate Data Using Least Squares 
Collocation 

AFGL-TR-76-0291 (September 1976) 

SCHAECHTER, D., KUROSAKI, M., and DE 
BrA, D, B. (Stanford Univ., Calif.) 

Study to Derelop Gmdioineter Techniques 
AFGL-TR-78-0046 (December 1977) 


SCHWARZ, K. -P. (The Ohio State Univ.) 
Goedetic Accuracies Obtainable from Measurements 
of First and SecondsOrder Gravitational Gradients 
AFGL-TR-76-0180 (August 1976) 

Simulation Study of Airborne Gmdiometry 

AFGL-TR-77-0129 (May 1977) 


Shapiro, 1.1., and Counselman, C. C., III 

(Mass.Inst. ofTechnol.) 

Laser Ranging and Very-Long-Baseline 
Interferometry for Geodetic Applications 
AFGL-TR-78-0057 (February 1978) 



174 


SJOBERG, L. (The Ohio State Univ.) 

A Comparison of Bjerhammar's Methods and 
Collocation in Physical Geodesy 
AFGL-TR-78-0203 (July 1978) 

On the Errors of Spherical Harmonic Developments of 
Gravity at the Surface of the Earth 
AFGL-TR-77-0229 (August 1977) 

Potential Coefficient Determinations from Itf 
Terrestrial Gravity Data by Means of Collocation 
AFGL-TR-77-0241 (September 1978) 

The Accuracy of Gravimetric Deflections of the 
Vertical as Derived from the Gem 7 Potential 
Coefficients and Terrestrial Gravity Data 
AFGL-TR-77-0287 (November1!) 7 ') 

SOLOMON, S. C. (Mass Inst oi'Teehnol.) 

The Relationship Between Marine Gravity and 
Bathymetry 

AFGL-TR-78-0234 (27 September 1978) 

SUNKEL, H. (The Ohio State Univ.) 
Approximation of Covariance Functions by Non- 
Positive Definite Functions 
AFGL-TR-78-0177 (May 1978) 

Syverson, C. R., Blaney, J. I., Jr., 
Hartnett, E. B., and Molineux, C. E. 

(Boston Coll., Chestnut Hill, Mass.) 


Geokinetic Environment Stuaies 
AFGL-TR-78-0124 (May 1978) 

Thomas, S. W., and Heller, W, G. (The 

Anal. Sei. Corp., Reading, Mass.) 

Efficient Estimation Techniques for Integrated 
Gravity Data Processing 
AFGL-TR-76-0232 (30 September 1976) 

Trotter, J. (DBA Sys., Inc., Melbourne, Fla.) 
Short Arc Reduction of Radar Altimetry Computer 
Program 

AFGL-TR-77-0170 (July 1977) 

TSCHERNING, C. C. (Ohio State Univ.) 
Covariance Expressions for Second and Lower Order 
Derivatives of the Anomalous Potential 
AFGL-TR-76-0052 (January 1976) 

UOTILA, U. A. (The Ohio State Univ.) 

Studies in Gravimetric Geodesy 
AFGL-TR-78-0302 (December 1978) 

UOTILA, U. A., and RAPP, R. H. (TheOhio 
State Univ,) 

Final Report on Studies of the Earth’s Gravity for 
Geodezic Purposes 
AFGL-TR-78-0301 (December 1978) 


J 






''T TWmrwTWtijij** 


VII OPTICAL PHYSICS DIVISION 


The Optical Physics Division conducts re¬ 
search on the optical and infrared properties 
of the natural and man-made environment 
and radiation sources. This includes atmos¬ 
pheric transmission, infrared backgrounds, 
target signatures, and the development of 
new optical and spectroscopic techniques. 
Infrared backgrounds include the earth, 
atmosphere, aurora, airglow, horizon or 
earthlimb, celestial sky, zodiacal emission, 
and such man-made backgrounds as urban 
areas or nuclear weapon detonations. The 
research ranges from field measurements 
using aircraft, balloons, rockets and satel¬ 
lites to laboratory studies on molecular 
spectroscopy and interactions, electron 
excitation and high velocity collision phe¬ 
nomena, and theoretical studies and anal¬ 
yses. 

The goal is to develop “tools” that can be 
used directly in the design and operation of 
Air Force and DoD systems. These tools 
include various data bases, models and 
computer codes such as the LOWTRAN 
atmospheric transmission and HITRAN 
laser transmission computer codes, the 
AFGL IR Star Atlas, and the LWIR Earth 
Limb Model. 

The portion of the electromagnetic spec¬ 
trum studied extends in wavelength from 
2,000 A in the ultraviolet to 1 cm where the 
far infrared blends into the microwave radio 
spectrum. 

The research in the Division is divided 
into studies of: the visible and near visible 
properties of the atmosphere, where aero¬ 
sol and molecular scattering is the pre¬ 
dominant mechanism of attenuation; the in¬ 
frared properties of the lower atmosphere 


176 


where thermal equilibrium usually prevails; 
the optical and infrared properties of the 
upper atmosphere (including auroras and 
airglow) where individual molecular inter¬ 
actions must be considered; the infrared 
properties of exoatmospheric sources — 
stars, nebulae, zodiacal dust; measure¬ 
ments of the radiation from man-made 
sources such as missile or aircraft plumes or 
urban areas; and development of improved 
techniques for spectroscopic measure¬ 
ments. 

A major area of investigation by the Divi¬ 
sion concerns atmospheric attenuation or 
transmission of radiation by the atmos¬ 
phere, including laser beams. Atmospheric 
molecules absorb optical and infrared radi¬ 
ation selectively at discrete wavelengths. 
Extensive computer programs have been 
developed which make use of the vast collec¬ 
tion of spectroscopic data for molecules 
(AFGL Atmospheric Absorption Line 
Parameters Compilation) and which permit 
the calculation of this transmission, par¬ 
ticularly for laser beams (HITRAN). De¬ 
tailed atmospheric absorption curves and 
tables for high resolution and laser trans¬ 
mission are available. The well known 
LOWTRAN atmospheric transmission 
computer code is used for determining the 
low resolution (approximately 20 wavenum¬ 
bers) transmission of the atmosphere for 
any path through the atmosphere for a wide 
range of tactical weapon delivery problems 
under various meteorological conditions. 
Both the LOWTRAN and HITRAN codes 
have been designated as the standard 
atmospheric codes for the Department of 
Defense as part of the DoD transmission 
program and for the international research 
community as part of the Technical Coor¬ 
dination Program and the International 
Radiation Commission. The application of 
these codes to the emission and trans¬ 
mission of radiation from hot gases and 
plumes is under way. 

The measurement and use of atmospheric 
transmission and emission also provide a 
method for remotely sensing atmospheric 


composition and meteorological conditions 
such as temperature, humidity, and ozone 
content. The transmission codes have been 
extensively applied to the design and im¬ 
provement of remote atmospheric sensing 
instrumentation on the Air Force meteoro¬ 
logical satellites. 

Scattering by aerosols and molecules in 
the atmosphere also contributes both to at¬ 
tenuation and to reduction in the contrast of 
a target seen through the atmosphere. Ex¬ 
tensive measurements in Europe as part of 
the NATO OPAQUE Program and from the 
Division’s C-130 Flying Laboratory have 
been made to determine the geographic, 
seasonal and altitude variations, as well as 
the optical properties of these aerosols. The 
results of these measurements are applied 
to target acquisition and detection prob¬ 
lems. 

Similarly, infrared backgrounds against 
which a target must be located are a major 
concern of the Division efforts. Such emis¬ 
sions from the atmosphere or celestial sky 
represent interfering background noise 
superimposed on the optical/IR target sig¬ 
natures that a surveillance system may be 
trying to detect. The emission of the lower 
atmosphere can be calculated from com¬ 
puter programs similar to those discussed 
previously. However, the emission from the 
upper atmosphere (above about 70 km) re¬ 
quires a much more detailed knowledge of 
the interactions and collisions among the 
individual molecules, many of which will be 
in excited states with excess energy. The 
amount and wavelength of the radiation re¬ 
sulting from this non-equilibrium chem¬ 
istry, and the effects of disturbances by pro¬ 
tons and electrons as would occur during an 
aurora or a nuclear burst are also being 
studied. Therefore, a sizable laboratory and 
theoretical research program is conducted 
to study the physics and chemistry of the 
atmosphere, particularly those molecular 
interactions which lead to infrared emis¬ 
sion, as well as an extensive measurement 
program. This has included both the use of 
the Division’s NKC-135 optical/infrared 



177 



The exterior of the LABCEDE tank. The 
facility is approximately 15 feet long and 4 feet 
in diameter. The 32 inch diffusion pumps ex¬ 
tend through the floor into the pump room be¬ 
low. The original electron beam was installed 
at the right hand end but has since been re¬ 
placed by one mounted perpendicular to the 
axis, approximately at the center of the tank. 

flying laboratory, and rockets, particularly 
in Alaska, where the infrared emission of 
the aurora is studied. Computer programs 
have been developed to predict and compute 
the IR emission of the earth limb and upper 
atmosphere, both for natural and disturbed 
conditions. Such background emission, par¬ 
ticularly during disturbed conditions such 
as auroras, could seriously impair the opera¬ 
tion of surveillance, detection, tracking, or 
terminal guidance systems. 

A satellite or rocket-borne infrared sys¬ 
tem looking away from the atmosphere will 
still see the celestial sky as a background. 
Consequently, the Division is carrying out a 
rocket program to map the celestial sky as 
well as zodiacal emission in the infrared. 
Also, measurements of missile and aircraft 
plumes are being obtained from rockets and 
aircraft. 

An inseparable part of these measure¬ 
ments and studies is the development and 
use of very sensitive advanced cryogen- 
ically cooled infrared sensors and spec¬ 
trometers by the Division. Such a technique 
to which the Division has made significant 
contributions is multiplex spectroscopy," 


where all wavelengths entering the spec¬ 
trometer-interferometer are analyzed 
simultaneously. This has included the devel¬ 
opment of a unique liquid-helium cooled 
high-resolution interferometer (HIRIS) 
which has been flown successfully on a 
rocket and is planned to be flown on future 
shuttle sorties. In addition, novel optical 
techniques are being explored to 
discriminate targets from these back¬ 
grounds. 

ATMOSPHERIC TRANSMISSION 

The atmospheric transmission of electro¬ 
magnetic radiation in the ultraviolet, 
visible, infrared and even in the millimeter 
wave region is affected by molecular 
absorption and scattering and by extinction 
from particulates (dust, haze, fog, rain) in 
the atmosphere. The relative importance of 
these different attenuation processes de¬ 
pends on the wavelength of the radiation 
and on the atmospheric conditions. 

In general, molecular absorption dom¬ 
inates the infrared to millimeter region of 
the spectrum, whereas aerosol extinction 
dominates the visible part of the spectrum. 
This domination is not complete, however, 
and a full understanding of atmospheric 
propagation requires thaz we deal with the 
appropriate molecular and aerosol effects at 
all wavelengths. Molecular absorption is 
highly wavelength dependent, whereas 
aerosol extinction varies much more slowly 
with wavelength. In the infrared, this rapid 
wavelength dependence tends to determine 
the “windows” within which atmospheric 
propagation is possible, whereas the trans¬ 
parency within these windows tends to be 
determined by more slowly varying molec¬ 
ular “continuum” and aerosol effects. As a 
result, aerosol and cloud attenuation can be 
the critical factor not only for visible wave¬ 
lengths, but also for infrared radiation in the 
window regions. 

Aerosol and cloud drop attenuation can 
affect radiation propagation in several 
ways. Particulate scattering and absorption 



NUMBER 


178 


along with molecular attenuation reduces 
the intensity of a beam of radiation as it 
travels along an atmospheric path and 
thereby becomes a factor in determining 
beam transmittance (e.g., in laser beam 
propagation). For many applications one is 
not only concerned with the extinction loss 
in a beam of radiation, but also with the 
intensity and angular distribution of the ra¬ 
diation scattered out of the direction of 
propagation of the direct (incident) beam. 
One of the most important effects of this 
scattered radiation is the reduction of con¬ 
trast in imaging systems at visual and near 
IR wavelengths. The scattered light from 
the sun forms the background sky radiance 
against which objects may have to be 
viewed and detected. 



I_i-1- 

o i to 

SIZE (microns) 

Changes in particle size distributions as air 
masses change. Winds from the southwest 
brought air containing large numbers of small 
particles (lee ithan Vm) on July 26,1977 (light 
curve). On July 26, the winds shifted to the 
northwest, and the number of small particles 
dropped by a factor of 10 (dotted curve). On 
July 27, the wind returned to the southwest, 
and the numer of particles less than 1 /im rose 
again to the concentrations noted on July 25 
(heavy curve). 


With some exceptions, which are dis¬ 
cussed below, the attenuation processes by 
atmospheric molecules are sufficiently well 
understood to make accurate predictions of 
the attenuation effects when the basic 
atmospheric properties such as molecular 
concentrations, air temperature, and pres¬ 
sure are known. 

It is much more difficult to predict accu¬ 
rately the optical properties of particulate 
matter in the atmosphere, especially those 
of haze and dust particles. Their optical 
effect is not only a function of particle con¬ 
centration, but also of particle size, shape, 
chemical composition and physical struc¬ 
ture. All these properties are highly vari¬ 
able with weather conditions and location 
and they are very difficult to measure. Be¬ 
cause of the extreme variability of these 
properties, it is also very difficult to develop 
models for the optical/IR properties of aero¬ 
sol particles or droplet clouds. 

The final goal of this research in the Op¬ 
tical Physics Division has been the devel¬ 
opment of computer codes which allow an 
efficient and accurate calculation of these 
various atmospheric propagation prop¬ 
erties. 

Measurements: The Optical Physics 
Division has directed a significant portion of 
its efforts toward experimental studies of 
the aerosol optical/IR properties and the 
development of realistic and representative 
models for these properties. One of these 
experimental efforts during the past two 
years was performed as part of a larger 
measurement program involving several 
NATO countries in Europe. Under this pro¬ 
gram, called Project OPAQUE (OPtical 
Atmospheric Quantities in Europe), rou¬ 
tine measurements of visible and IR trans¬ 
mittance, path radiance, illuminance, and 
meteorological parameters including aero¬ 
sol properties are being made at selected 
sites. 

The Air Force Geophysics Laboratory, in 
cooperation with the Federal Republic of 
Germany, has been conducting these mea¬ 
surements on a regular basis since the win- 



179 


< 


1 

1 


i 



ter of 1976-1977 in Northern Germany. This 
measurement program has already resulted 
in a number of important conclusions on the 
physics of aerosols and on the effect of aero¬ 
sols on the propagation of radiation. A few 
examples are presented below. 

Aerosol Data and Models: Air mass 
optical and aerosol properties are modified 
by continental and anthropogenic in¬ 
fluences. In particular, the maritime polar 
air masses reaching Northern Germany 
from the North Atlantic are modified by 
their passage over England, France and/or 
the industrialized low countries. The degree 
of modification is directly related to the tra¬ 
jectory followed by the air mass and the 
residence times along that trajectory. 
Aerosol data taken on three consecutive 
days, 25 to 27 July 1977, during a “surge” of 
maritime polar air, illustrate the effects of 
continental modification. 

The synoptic regime was relatively dis¬ 
tinct. During most of the day of 25 July, the 
measurement site was in front of a north¬ 
east-southwest oriented cold front in an 
area of light southwesterly winds. On 26 
July, after the frontal passage and a 
strengthening of the low pressure center 
over Norway, a surge of cool maritime polar 
air moved rapidly from the open ocean, over 
England and into Northern Germany. As 
this flow weakened during the night of the 
26th, a new frontal system was passing over 
France. As a consequence, on the 27th, the 
winds at the OPAQUE site swung back to 
the southwest After the frontal passage, 
the northwesterly flow was associated with 
better visibilities and rain showers. The 
associated aerosol samples indicate that 
with this change, the number of particles 
smaller than lp.m decreased by a factor of 10 
while the number of 10 n m particles 
increased by a factor of 10. The aerosol data 
from the 27th then i idicate that with the 
return of the southwesterly flow, the num¬ 
ber of small particles returned to the num¬ 
bers observed two days earlier in the south¬ 
westerly flow, and that the number of large 


particles decreased slightly from those in 
the northwesterly flow. 

The suggestion in these data is that the 
surge of air from the northwest was much 
cleaner overall than the air present on 25 
July, but that the maritime air is charac¬ 
terized by large numbers of larger particles. 
The data from the 27th are also probably 
from maritime polar air, but with a longer 
trajectory over industrialized areas. The 
result of this trajectory is the introduction 
of large numbers of small particles while at 
the same time larger particles are being 
removed by various physical processes. 
These results were expected and confirm 
some of the many concepts about air mass 
modification. It remains for us to broaden 
the knowledge base with appropriate cor¬ 
relation studies and to develop a useful 
statistical base for determining air mass 
characteristics after a given migration or 
stagnation. 

Another important question is: How does 
the composition, especially the size distri¬ 
bution of aerosols change with altitude? 
Vertical aerosol size distribution and ex¬ 
tinction coefficient variations were meas¬ 
ured on a number of aircraft survey flights 
in Europe in connection with the surface 
measurement program. Very often one 
finds in industrial urban environments a 
very distinct low level haze layer near the 
surface. The aircraft measurements show 
that the size distribution and also the com¬ 
position of aerosols can vary considerably 
with altitude, depending on the vertical 
structure of the atmosphere. 

Within the OPAQUE measurement pro¬ 
gram, aerosol particles have also been col¬ 
lected with high volume air samplers, and 
the aerosol substance subsequently 
analyzed for its refractive index and ab¬ 
sorption properties. From these studies it 
was found that the composition of aerosols 
varies not only with time and location, but 
that it is not uniform throughout the whole 
size range of particulates. The refractive 
index components (real and imaginary part) 
show some distinct spectral variations 



180 


TOTAL AEROSOL PARTICLE NUMBER (cm) 



TOTAL VOLUME SCATTERING COEFFICIENT (PER M) 

Comparative vertical profiles of measured 
scattering coefficients and aerosol number 
densities, as measured on a C-130 flight over 
the Baltic Sea on October 26, 1976. 

which can be associated with different 
chemical components. 

Based on the OPAQUE data and other 
experimental data from various research¬ 
ers, aerosol models have been developed 
and their optical and infrared extinction and 
scattering properties have been derived. 

Since measurements and theoretical 
studies by several scientists have shown 
that the aerosol size distribution and their 
refractive index change significantly at high 
relative humidities, these humidity de¬ 
pendent changes and resulting optical prop¬ 
erties were also incorporated into the op- 
tical/IR aerosol models. At relative humid¬ 
ities above approximately 70 percent, and 
especially in the 90 percent region, aerosol 
particles begin to adsorb water molecules 
and grow. The rate of growth is not the 
same for all particles. In general, it is 
higher, the more hygroscopic and the larger 
the particles. As a consequence, the optical 
properties of aerosols change and the wave¬ 


length dependence of the extinction coeffi¬ 
cient decreases. 

This change in optical properties of aer¬ 
osols with relative humidity depends very 
strongly on the chemical composition of the 
aerosols. Hygroscopic particles in maritime 
aerosols (sea salt) grow much more rapidly 
and at lower values of relative humidity 
than non-hygroscopic dry dust particles in a 
rural continental type aerosol. 

Such models of the optical/IR properties 
of aerosols have little reliability unless they 
can be verified against experimental data. 
Measured optical/IR propagation prop¬ 
erties from the OPAQUE program in 
Germany offer an extensive data base for 
such tests. They show that, in general, the 
IR extinction and scattering properties of 
the model describe the measured param¬ 
eters very well, using visibility and relative 
humidity as input parameters. The major 
uncertainty in such model calculations is the 
decision on which type of aerosol model best 
represents the aerosol composition at the 
time of the measurements of the optical/IR 
propagation properties; 

Atmospheric Transmission Modeling: 
The transmission modeling program in¬ 
cludes the effects of extinction by both 
molecular and particulate (aerosol) con¬ 
stituents of the atmosphere. Models for 
predicting the transmission, thermal emis¬ 
sion, and scattered radiation properties of 
the atmosphere have been developed for 
both high and low spectral resolution appli¬ 
cations. Two basically different trans¬ 
mission models have been developed. The 
underlying basis for their development is 
the spectral resolution of the calculated 
transmission which is primarily governed 
by the widths and spacing of atmospheric 
molecular absorption lines. 

The LOWTRAN 4 model differs from 
previous LOWTRAN models in its ability to 
compute thermal emission as well as atmos¬ 
pheric transmission. It maintains all the ca¬ 
pabilities included in its predecessor LOW¬ 
TRAN models: contributions by absorption 
lines, continuum absorption by water vapor 



181 


i 


i 


i 


i 


1 

j 

J 

l 


8 


f 

» 



and other molecular species, and the 
absorption and scattering by atmospheric 
aerosols. Work is proceeding to obtain new 
laboratory measurements of the water 
vapor continuum absorption, particularly in 
the 3 to 5 pun spectral region. A revised 
continuum model is planned for a forth¬ 
coming LOWTRAN model. Current LOW- 
TR AN modeling efforts are centered on the 
validation of the LOWTRAN code by 
comparison of the models with measure¬ 
ments made in the atmosphere. The empha¬ 
sis in these validation efforts is on aerosols. 


5 _ woe- "OOP 800 goo <00 a ocm'' 



AAVEIENGTH 


Absorption indexes of aerosols taken at the 
OPAQUE site in Northern Germany for par¬ 
ticles larger and smaller than 1 pm. 

The second atmospheric transmittance 
model, HITRAN, uses the summation of 
the individual molecular absorption line 
profiles of the various atmospheric gases to 
determine the monochromatic trans¬ 
mittance at each wavelength. This method 
is known as a “line-by-line calculation" and 
can be used to determine the transmittance 
of the atmosphere at any given spectral 
resolution by averaging over the required 
spectral interval. This is the only approach 
capable of computing very high resolution 
spectra for the transmittance of laser beams 
through the atmosphere. This approach 
may also be used to predict atmospheric 
propagation characteristics for spectral res¬ 
olution up to the 20 wavenumber capability 


of LOWTRAN. A new HITRAN routine 
known as FASCODE - (Fast Atmospheric 
Signature Code) has been developed 
recently. It computes high resolution 
spectra at a substantial saving of computer 
time. It has been published as FASCODE - 
Fast Atmospheric Signature Code 
(Spectral Transmittance and Radiance), 
AFGL-TR-78-0081. The FASCODE 
algorithm is based on an optimal sampling of 
simple mathematical functions, the sum of 
which is equal to a particular absorption line 
shape. 

A frequently asked question is: What 
laser frequencies are attenuated the least 
by the atmosphere? This question has been 
answered for carbon monoxide, hydrogen 
fluoride, deuterium fluoride and carbon 
dioxide laser systems in a summary report 
on laser transmittance (AFGL-TR-78-0029) 
which describes the new “LASER” code 
now available for distribution. In addition to 
addressing the problem of laser propagation 
of these specific laser systems, the summary 
report provides synthetic spectra for a large 
portion of the infrared, allowing a quick 
estimate of atmospheric attenuation for 
laser propagation. The compilation of 
atmospheric absorption lines used as a basis 
for much of our work is described in the 
AFCRL Atmospheric Absorption Line 
Parameters Compilation (AFCRL-73- 
0096). Since the publication of this report in 
early 1973, we have made available over 200 
copies of these data on magnetic tape. 
Additional short articles have been pub¬ 
lished to inform the scientific community of 
significant modifications and additions to 
the data base. Detailed information on over 
140,000 spectral lines in the spectral region 
from 0.68 ^im to the microwave region are 
contained on this tape. Atmospheric species 
included in the compilation are: H>0, COa, 
Q t , N-.0, CO, CH, and ft. 

A special version of the HITRAN code 
has been developed to calculate atmospheric 
transmission (attenuation) in the micro- 
wave, millimeter, and submillimeter wave 
regions. The frequency range considered is 





182 


1 to 1000 GHz or 0.03 to 33 wavenumbers. 
The clear atmosphere transmission spectra 
is calculated by a computer-efficient exten¬ 
sion of the HITRAN code. The hydro¬ 
meteor transmission of fog, clouds and rain 
(as calculated by Mie scattering) is ap¬ 
pended to this HITRAN code. This new 
code calculates atmospheric transmission 
for "all weather” transmission through an 
arbitrary atmospheric path. 



WAVELENGTH (MICROMETERS) 

57Sp 5775 577p 5765 

-F--—I-4-—i-)-(—-+-J-1 

1729.00 173000 I73IOO 173200 1733.00 173400 1735.00 

FREQUENCY (WAVENUMBERS) 

Comparisons of experimentally measured 
absorption lines of water with the AFGL line 
compilation. The low amplitude sinusoidal 
variation at the top of the measured spectrum 
is a channel spectrum caused by multiple 
reflections within the instrument. The wave- 
numbers predicted by theory and the differ¬ 
ences between theoretical and experimental 
values are noted for each line. 

Current efforts involve improving the 
HITRAN data base, both by correcting 
existing data and adding new material. New 
material to be added includes weak absorp¬ 
tion features of the major atmospheric ab¬ 
sorbing gases. Absorption parameters for 
trace atmospheric and pollutant gases com¬ 
prise a separate tape which is also available 
to the scientific community. The gases in¬ 
cluded on this trace gas tape are NO, NO>, 
NHi, and SO.-. Work is also under way on 
OH, HNQi, HC1 and HF. 

Research on molecular spectroscopy is 
being conducted to provide the capability of 
calculating molecular spectroscopic 
parameters related to some of these at¬ 
mospheric gases. The parameters being 


studied include transition frequencies, 
intensities, line widths, line shapes, and 
radiative lifetimes. Molecular constants are 
determined from available spectroscopic 
data and used to predict spectral informa¬ 
tion at desired conditions of temperature, 
pressure, and abundance. Computer codes 
have been developed to calculate molecular 
constants that are difficult to measure, 
including those for high vibrational states 
populated at high temperatures and for 
isotopic species that are significant in weak 
absorption regions of the atmospheric 
spectrum. 

Applications: During the past several 
years, a great deal of the modeling effort has 
been in direct response to specific applica¬ 
tion requirements. The development of the 
LOWTRAN code was spurred by such re¬ 
quirements. Both HITRAN and LOW¬ 
TRAN have been applied to a wide variety 
of laser and broadband tactical system 
design and application problems. 

Another application of the transmittance 
modeling activity is the problem of the satel¬ 
lite remote sensing of meteorological vari¬ 
ables. The Line Parameters Compilation 
has been used as a data base for such calr.t- 



WAVELENGTH (pm) 

Atmospheric transmission along a vertical 
path from sea level to space, computed with 
the LOWTRAN model. 




I Mil TAMM i VJCJ m 


l'« 


lations to determine the spectral channels 
most suitable for use in satellite sensor 
design. In addition, transmittance calcula¬ 
tions performed with these models are 
being used in the development of software 
packages for the reduction of satellite-mea¬ 
sured radiances in terms of the three dimen¬ 
sional structure of temperature and 
moisture. 

The Line Parameters Compilation has 
also been applied to the understanding of 
the sugnature of a hot gas (for example, the 
exhaust plume of an aircraft) as viewed 
through a colder intervening atmosphere. 
In conjunction with aircraft-borne measure¬ 
ment programs, these calculations allow us 
to investigate the altitude and range 
dependence of exhaust plume emission 
signatures. 


COMPARISON OF LOWTHAN AND OPAQUE TRANSMITTANCE 



Comparison of LOWTRAN calculation of 
transmittance along a path in Northern 
Germany with OPAQUE program measure¬ 
ments. 


Remote Sounding: The first meteoro¬ 
logical satellites were designed to transmit 
cloud pictures. It was soon realized that the 
atmospheric emission in the thermal infra¬ 
red region of the spectrum was related to 
the temperature of the atmosphere, so that 
remote passive temperature sensing was 
possible. This possibility follows from the 
relation between the atmospheric emission 


in the thermal infrared region of the spec¬ 
trum and the vertical atmospheric temper¬ 
ature field. Vertical temperature infer- 
encing became operational in 1970 with the 
orbiting of the Vertical Temperature Profile 
Radiometer (VTPR) sounder aboard a 
NASA-NOAA meteorological satellite. 
Similar data observed by the Defense 
Meteorological Satellite Program (DMSP) 
became generally available in 1974. Later 
versions of these vertical sounding systems 
also contain spectral channels intended to 
sound the vertical distribution of water 
vapor, a parameter of substantial interest to 
the Air Force. 

Work in the Division has been concen¬ 
trated in two areas. First, the trans¬ 
mittance modeling described above has 
been applied to the development of new 
design concepts and data anai.,si- -•! 
for the remote sounding of the »•< ,1 ■ . 
tributions of temperature and v.a 
in the infrared and microwave regions ol'the 
spectrum. Modifications to existing infr -a 
sensors have been proposed and con¬ 
structed and these modified sensors will be 


SATELLITE TEMPERATURE SOUNDING 
USING ISpm BAND 



Satellite temperature sounding using the 
15^m band. Arrows indicate the approximate 
atmospheric levels from which the radiation at 
the frequencies of the DMSP channels is 
emitted to space. 



184 


flown on future Defense Meteorological 
Satellites. A study of water vapor and 15- 
/im carbon dioxide transmittances is under 
way to aid in the understanding and inter¬ 
pretation of discrepancies found in compar¬ 
ison of satellite measured and computed 
atmospheric radiance distributions. Sec¬ 
ond, the ultimate utilization of the satellite 
measured radiances in the thermal infrared 
requires an inversion procedure, a mathe¬ 
matical device whereby either the vertical 
distribution of temperature (or water 
vapor) or the vertical distribution of the 
sources and sinks of radiation in the atmos¬ 
phere are derived from a spectral scan of the 
upwelling radiance. This information is then 
fed into dynamical models of atmospheric 
motion as a key element of weather fore¬ 
casting on various scales. 

Using such a spectral scan to determine 
the temperature (or moisture) at each level 
in the atmosphere has proved to be very 
difficult. All levels of the atmosphere con¬ 
tribute at each particular frequency, so that 
the radiance sensed by the satellite is a mix¬ 
ture of thermal information from all levels. 
Probing different frequencies merely 
weights radiation according to height, de¬ 
pending on the transmittance of the atmos¬ 
phere. 

Mathematically, the radiation is expres¬ 
sible as an integral transform of the temper¬ 
ature-related Planck intensity summed 
over the atmosphere. Typically, the radi¬ 
ances are observed over six to eight dif¬ 
ferent frequency channels. The vertical 
temperature distribution is then recover¬ 
able as an inverse transform of the radiance 
profile; hence, the name inversion given to 
this particular inference problem. The heart 
of the problem is that the vertical tempera¬ 
ture distribution is deduced from intensity 
differences between neighboring frequency 
channels, a second order effect. First, the 
finite number of channels of observation 
means that many solutions for the tempera¬ 
ture profiles are possible. Second, most 
inversion methods use some a priori algo¬ 
rithm in an attempt to smooth out the inevit 


WAVELENGTH IHICRON) 



Average spectral radiance values of snow and 
clouds as measured from the AFGL KC-135 
aircraft. 

able noise in the data and thus run the risk of 
discarding useful information. Techniques 
are being developed which will recognize 
noise in the radiation measurement data and 
eliminate it from the data base which is then 
used to infer temperature profiles. 

Snow Cloud Discrimination: Near 
infrared spectral measurements were taken 
of snow, cirrus, and cumulus backgrounds 
by the Air Force Geophysics Laboratory’s 
KC-135 aircraft. Based on an analysis of 124 
aircraft measured spectra, the spectral re¬ 
flectance characteristics of snow, cirrus and 
cumulus between 5500 and 7000 wave- 
numbers were determined. Certain snow 
cloud discrimination design parameters 
were identified, i.e., slope of the spectral 
radiance, absolute spectral and/or total 
radiance and the location and value of the 
maximum spectral radiance for each back¬ 
ground. It was suggested that an optimum 
snow cloud discrimination should be based 



185 


on the measurement of the slope of the 
spectral radiance in this near infrared 
region. 

INFRARED BACKGROUNDS 

It is impossible for a sensor to observe or 
look in any direction without encountering 
the emission or radiation from some “back¬ 
ground” — whether it is the celestial sky, 
the earth and clouds, the horizon or earth 
limb, the aurora or airglow, the atmosphere 
itself or even manmade backgrounds such as 
nuclear explosions or urban areas. Much of 
the research of the Division is devoted to 
obtaining direct measurements of these 
backgrounds, and developing data bases, 
models and codes to describe these back¬ 
grounds and the phenomenology related to 
them. 

In particular, the optical/infrared prop¬ 
erties of the upper atmosphere, both under 
normal conditions and when it is disturbed 
by auroras or nuclear backgrounds, is a ma¬ 
jor scientific area. At the altitudes consid¬ 
ered, thermal equilibrium usually does not 
exist, and it is necessary to consider the 
collisions or interactions of individual pairs 
or triads of molecules, one or more of which 
may be an excited state (that is, with excess 
internal energy). Extensive laboratory and 
theoretical studies, as well as rocket and 
aircraft measurements of upper atmos¬ 
pheric optical/infrared phenomena, are 
carried out. The results of these laboratory 
studies and aircraft measurements also 
apply to missile or jet engine plume infrared 
radiation. The goal of the research is to gen¬ 
erate both directly measured data and 
models and computer codes that permit the 
prediction of the optical/infrared emission of 
the upper atmosphere, particularly under 
disturbed conditions. Such data and codes 
are particularly applicable to surveillance 
and detection systems operating in space or 
near space. 

Aircraft Measurement Program: AFGL 
uses a modified NKC-135 aircraft as an 
Infrared Flying Laboratory. This aircraft is 



The AFGL Infrared Flying Laboratory. The 
viewing ports, except for those looking 
straight up or straight down, are visible in this 
picture. 

configured with 55 viewing windows and 
ports behind which various radiometers, 
interferometers, spectrometers, and spatial 
mappers can be operated to collect basic 
infrared data. The range of this aircraft 
allows worldwide deployment and permits 
the infrared research scientists to study the 
environment well above obscuring clouds 
and atmospheric constituents. This NKC- 
135 has been serving as a reliable platform 
to study geographic and seasonal impacts 
upon infrared processes in the aurora and 
atmosphere. These studies are coordinated 
with balloon and rocket-borne measure¬ 
ments with the data used to test specific 
theoretical and laboratory-based modeling. 

A variety of unique instrumentation is 
carried on board the Infrared Flying Lab¬ 
oratory. Three Michelson interferometers 
are utilized, two of which are mounted at 
side-looking windows and the third at a 
down-looking window in the converted 
refueling “boomer’s compartment.” These 
instruments have been designed and built 
by a member of the scientific air crew and 
the data obtained are widely acclaimed by 
the DoD infrared community. Two thermal 
scanners are operated simultaneously with 
the interferometers, providing infrared 
imagery that serves a dual purpose: 1) pro- 


4 ," 





186 




viding independent sensor data of phenom¬ 
ena being measured; and 2) providing visual 
support enabling better interpretation of 
interferometric spectral data. One scanner 
is mounted at a side window and the second, 
with a cryogenically cooled detector, is 
mounted at a downward window adjacent to 
the down-looking interferometer. Temporal 
data are obtained from a four channel 
radiometer mounted at a side window. An 
array of 16 mm tracking cameras and a 
television camera provide visual docu¬ 
mentation of subjects being observed. 

The data obtained with these various in¬ 
struments are recorded on analog tape re¬ 
corders and the tapes returned to the labo¬ 
ratory for reduction. From the interfer¬ 
ometers come digital plots of infrared spec¬ 
tra in units of absolute spectral radiant in¬ 
tensity for targets, or absolute spectral 
radiance for backgrounds and extended 
sources. The infrared scanners provide 
computer enhanced imagery that gives dif¬ 
ferential radiance with respect to the mean 
radiance of the scene. The radiometer pro¬ 
vides calibrated source radiances that can 
be compared with integrated spectral data; 
if the source varies in intensity, curves may 
be obtained from computer plots showing 
time history of the measured radiation. 

Interferometric and spatial data products 
are generated in the laboratory by a power¬ 
ful array of minicomputer hardware. The 
interferometric data are transformed from 
raw analog interferograms into digitized 
spectra with a minicomputer and Fourier 
analyzer. The spatial imagery data are 
processed and converted to television 
images that are calibrated relative to an 
arbitrary background level by the mini¬ 
computer. The images are displayed on a 
standard TV monitor in a 16-step grey scale 
format by a video display unit. 

The airborne infrared measurements pro¬ 
gram is collecting large amounts of data on a 
variety of targets and backgrounds. Spec¬ 
tral and spatial background data have been 
collected on desert, urban, rural, culti¬ 
vated, mountain, snow, and water back¬ 


grounds. Sky background data consists of 
several cloud types viewed from above and 
below at several altitudes and various solar 
azimuth and elevation angles. In addition, 
continuous urban and rural data have been 
obtained for a period of approximately five 
hours, beginning before sunset and ending 
after sunset for three different seasons of 
the year. 

The aircraft missions have obtained data 
necessary to Air Force and DoD research 
and development programs. A typical ex¬ 
ample of field data is taken from a mission of 
December 1975 over the desert of Death 
Valley, California. Circling at 25,000 ft 
above the desert floor, the interferometer 
and the spatial mapper recorded the infra¬ 
red signature during the entire 360 degree 
orbit. Such measurements show that spec¬ 
tral radiance reaches maximum intensity 
when the viewing angle is away from the 
sun and minimum when the viewing angle is 
into the sun. This occurs because the per¬ 
centage of shaded surface is minimized and, 
therefore, reflection of solar radiation is 
maximized when viewing away from the sun 
and vice versa. Comparison of calculated 
surface temperature based upon spectral 
analysis has been close to weather data 
surface readings in view of the uncertainties 
of thermal coupling of the surface with the 
atmosphere, intermittent shading by 
clouds, and so forth. This has helped estab¬ 
lish confidence in the reliability of the data. 

Design, construction, and testing con¬ 
tinues with follow-on generations of in¬ 
strumentation. An interferometer has been 
equipped with an automatic mirror 
alignment system that promises to con¬ 
tribute even more stability to the data. A 
new interferometer is under construction 
which incorporates a unique linear drive 
system for the primary mirror and an im¬ 
proved servo-controlled alignment system. 
This new instrument will be capable of 
producing data with 0.1 wavenumber 
resolution. A new FLIR spatial mapper 
system has recently been installed in the 
NKC-135 and will begin testing in January 





187 


1979. It will provide thermal imagery with 
four times the resolution of the infrared 
scanners currently in use. 

Balloon-Borne Measurements: The 
purpose of the Balloon Altitude Mosaic 
Measurements (BAMM) Program is to ob¬ 
tain infrared background data related to the 
stability of the earth/atmosphere as a radia¬ 
tion source. The measurements are de¬ 
signed to measure the scintillation produced 
by the atmosphere, characterize the IR 
emission properties of clouds, obtain earth 
emission correlation lengths and observe 
the noise spectrum of the radiation from the 
earth/atmosphere system. To measure 
these parameters, it is necessary to observe 
them from a stabilized platform from which 
the optical path always traverses the same 
portions of the atmosphere. Consequently, 
a high-altitude, slow-moving balloon carry¬ 
ing a trainable platform was selected as the 
vehicle to carry the IR instruments. The 
platform performs mechanical maneuvers 
to compensate or eliminate balloon motions 
of rotation, pendulation, and drift. A gyro¬ 
sensor-servo system automatically con¬ 
trols, through a microprocessor, a three- 
axis gimbal to maintain continuously point¬ 
ing stability to better than one arc-sec per 
sec. With this very accurate inertial stabil¬ 
ization, a point on the earth’s surface can be 
observed in a staring mode Such that the 
observed image does not move appreciably 
in over three minutes. Measured changes in 
the intensity of radiation recorded in the 
stare mode may be directly related to 
atmospherics affecting the radiation; for 
example, twinkling. In addition to main¬ 
taining a constant line-of-sight, the platform 
is capable of scanning 360 degrees in azi¬ 
muth and horizon-to-horizon in elevation to 
obtain spatial frequency measurements and 
thus isolate the scintillation from changes 
produced by ground structure. 

A radiometer and Michelson interfer¬ 
ometer located on the balloon platform 
measure the infrared. Both instruments 
have 4x4 mosaic detector arrays in the focal 
plane which image 0.8 x 0.8 km of the earth 



A typical desert background measurement. 
The visual photo, spectrum, and thermal 
image were taken at the same time from 
25,000 feet altitude. The sun was in the 
sout hwest (216 degrees) and 22 degrees above 
the horizon. The aircraft banked 45 degrees 
and was flying northwest (286 degrees) when 
the picture was taken. 









surface on each detector in the array. The 
radiometer contains fixed band filters which 
may be changed on ground command while 
the interferometer covers the 2.5 to 5.5 ^m 
spectral range with ten wavenumber reso¬ 
lution. Spectral measurements are recorded 
in the staring mode so as to obtain the back¬ 
ground temporal changes within each spec¬ 
tral element over the frequency range of DC 
to 10 Hertz. 

A TV camera mounted on the pointing 
platform is used for visual real-time back¬ 
ground scene acquisition and system navi¬ 
gation. The TV package is a standard 
camera modified optically to provide a 
ground resolution of 1,000 feet at the balloon 
altitude of 100,(KM) feet. With a motorized 
zoom feature, the TV scene can be changed 
to increase the spatial resolution by a factor 
of 10 to give 100 feet ground resolution. All 
instruments are boresighted to view identi¬ 


The gondola for the Balloon Altitude Mosaic 
Measurements (BAMM) Program. The sensor 
and television camera have been rotated so 
that they are looking sideways. 


cal scenes on the earth’s surface in order to 
analyze and compare the infrared intensity 
of different background scenes, such as 
clouds, mountains, lakes, or desert, with 
the visible scene. 

The first measurements using the special¬ 
ized payload were made in September 1978 
from Holloman AFB, New Mexico, from a 
2.7 million cubic foot balloon. Infrared data 
and TV video pictures were collected on a 
variety of backgrounds typical of the desert 
surroundings. Preliminary analysis of the 
data shows that the infrared power de¬ 
creases with the square of the spatial fre¬ 
quency. Measurements are planned for the 
spring and fall of 1979 ir, the southeastern 
and southwestern parts of the United 
States. 



The BAMM payload and balloon ready for 
launch. 


Background Measurements in Space: 

The Air Force needs to detect infrared 
emitting targets in space at the greatest 
possible range. Because these targets are 
always viewed against background radi¬ 
ance, knowledge of this radiation is neces¬ 
sary to permit discrimination of the target 
from the background. These backgrounds 
include the celestial sky, zodiacal emission 
and radiation from the earth limb, aurora 
and upper atmosphere. 

The scope of the problem is determined 
by the requirements of the space surveil- 










189 


lance program. The first requirement is a 
specification of the celestial background. 
We must be concerned not only with stars 
but, in addition, take into account the 
effects of zodiacal radiation — that is, 
thermal emission from particles distributed 
about the ecliptic plane caused by the ab¬ 
sorption of solar radiation. The additional 
requirement to observe ow-altitude satel¬ 
lites means that we mast determine the 
lower limit set by the earth’s upper atmos¬ 
pheric limb radiance. 

The Division has conducted a series of 
experiments to obtain infrared survey data 
on the celestial background with state-of- 
the-art cryogenically cooled sensors flown 
on rocket probes. The thrust of the program 
has been threefold: to obtain the most 
complete sky coverage possible with as high 
a sensitivity as comparable with the need to 
cover a large area on each flight; to generate 
from these data a background map; and to 
apply these data to the model to extend 
statistically the empirical data base to faint 
irradiance levels. 

To date, about 79 percent of the sky has 
been surveyed at an effective wavelength of 
4.2 ym, 90 percent at 11 p.m, 87 percent at 
20 fim and 36 percent at 27 ym. The data 
have been published in The AFGL Four 
Color Infrared Sky Survey: Catalog of 
Observations at 4.2, 11.0, 19.8 and 274 ym 
(AFGL-TR-76-0208). A subsequent catalog 
(AFGL-TR-77-0160) extends the data to 
sources observed with low confidence. 
Many of these latter sources have been con¬ 
firmed by ground-based observations. 

Present plans are to develop instru¬ 
mentation to be flown on an ARIES compat¬ 
ible payload which gimbals the cryogenic 
sensor. Each flight will survey approxi¬ 
mately 35 percent of the sky at effective 
wavelengths of 11,20 and 28 ym. The optics 
will permit scanning to -55 degrees in dec¬ 
lination from White Sands Missile Range 
with no degradation in sensitivity, permit¬ 
ting coverage of the important area south of 
the galactic center. 


Preliminary data for the earth limb and 
zodiacal radiances were obtained August 3, 
1976, from a rocket probe launched at White 
Sands Missile Range, New Mexico. The 
experiment took advantage of the excellent 
out-of-field-of-view rejection character¬ 
istics of the sensor. The combined exper¬ 
iment obtained data of the earth’s atmos¬ 
phere as well as zodiacal data, particularly 
at angles close to the sun. The zodiacal 
light represents the limiting background for 
observations made in deep space. The 
present program envisions experimental 
flights to provide the basis for a complete 
model of the zodiacal light. The cryogenic 
sensors for carrying out these meas¬ 
urements are being designed and con¬ 
structed at AFGL. 

Parallel efforts to develop computer 
codes which model the infrared radiance 
from the upper atmosphere have been 
under way for the past five years. The model 
incorporates photochemical and thermal 
emission mechanisms for the major infrared 
active molecular species. Radiance profiles 
can be generated in the 5 to 25 /xm region up 
to 500 km altitude. A new model (AFGL- 
TR-77-0271) which incorporates revisions 
made since 1974 is now available. A rocket 
probe program to measure the vertical dis¬ 
tribution of atmospheric radiation is cur¬ 
rently under way. Launches are scheduled 
for sunrise, noon and sunset to obtain the 
diurnal variation of the atmospheric back¬ 
ground. The data, which will cover the 3-22 
region, are intended to update the cur¬ 
rent infrared limb radiance model. 

CIRRIS: An experiment called CIRRIS 
(Cryogenic Infrared Radiance Instrumen¬ 
tation for Shuttle) is being conducted by 
AFGL with flights on space shuttle planned 
for 1982 and 1984. This experiment will 
obtain high resolution spectral and spatial 
data of the infrared emissions from aurora, 
airglow and earth limb backgrounds as well 
as obtain much needed data on contamin¬ 
ation of the space shuttle environment. The 
CIRRIS I sensor to be flown in 1982 will be a 




190 


combined interferometer-radiometer con¬ 
taining a single detector element. The 
CIRRIS II sensor will have a 14 element 
detector array in both the interferometer 
and radiometer to provide simultaneous 
data on spectral radiance and spatial distri¬ 
bution of emissions over the broad spectral 
range from 2.7 to 25 /am. The sensor design 
is based on the liquid helium cooled inter¬ 
ferometer-spectrometer technology devel¬ 
oped at AFGL. The experiment is planned 
for 7 to 14 day shuttle sortie flights with low 
altitude, high inclination orbits. 

SPIRE: A rocket experiment called 
SPIRE (Spectral Infrared Rocket Exper¬ 
iment) was conducted by AFGL under the 
sponsorship of the Defense Nuclear Agency 
to investigate earth limb infrared emis¬ 
sions. The 2100 lb. payload was launched on 
a Talos Caster rocket on September 28, 
1977, near dawn from the University of 
Alaska’s Poker Flat Research Range and 
achieved an apogee of approximately 285 
km. Primary sensors on the payload in¬ 
cluded two circular variable filter (CVF) 
infrared spectrometers covering the wave¬ 
length region from 1.40 to 16.5 p.m and a 
dual channel photometer to measure visible 
emissions in narrow bands centered at 4977 
A and 6972 A. The sensors were coaligned 
and equipped with high off-axis rejection 
telescopes with nominal fields of view of 1/4 
degree full angle which provided an optical 
footprint size of about 8 km at the tangent 
height point. The payload attitude during 
ballistic flight was controlled by an inertial 
system programmed to accomplish vertical 
spatial scanning through the day, termin¬ 
ator and night portions of the earth limb 
region. Excellent data were obtained from 
the primary sensors during rocket ascent 
and descent resulting in over 1500 infrared 
spectral scans from the spectrometers and 
400 seconds of continuous photometer data. 
The emission data encompasses 12 vertical 
spatial scans from tangent heights of250 km 
down * j full viewing of the hard earth, as 
well as one spatial azimuth scan from full 


night, through the terminator, to full sun¬ 
light conditions. 


Artist's concept of the SPectral Infrared 
Rocket Experiment (SPIRE) mission showing 
the relationship of 12 spatial scans to the earth 
limb at the dawn terminator. 

High quality, first-of-a-kind spectra of 
high and low altitude molecular emission 
were obtained throughout the 1.4 to 16 /am 
spectral range. Non-equilibrium emissions 
above 60 km include the OH fundamental 
and overtone, NO at 5.4 pm, O 3 at 9.6 pm 
and CO 2 at 4.3 and 15 pm. Comparisons of 
these measurements with the AFGL devel¬ 
oped high altitude radiance model yield 
generally excellent agreement, with several 
notable discrepancies in the radiance pro¬ 
files. These include evidence of a second 
hydroxyl layer at 65 km and the apparent 
interruption in the steady drop of CO 2 15 
fjim radiance with altitude in the 100- to 
110-km region. This latter effect is similar to 
an “anomalous” CO 2 profile obtained earlier 
by a vertical viewing spectrometer during 
the ICECAP program. 

SPIRE’s limb viewing aspect combined 
with the high off-axis rejection capabilities 
of its sensors made it possible to probe down 
to altitudes within 15 km of the hard earth. 
This allowed measurements through the 
transition region to thermodynamic equi¬ 
librium (70 to 40 km) where models are in¬ 
accurate and in situ sounding rocket and 
balloon measurements do not overlap. 








191 


Results show a smooth transition for strato¬ 
spheric water at 6.5 /im, fluorescent O 2 'A, 
nighttime NO 2 , combination bands of CO 2 
and Os, and day to night invariant HNO 3 at 
11.3 /xm. Both spectra and radiance profiles 
of these emissions agree well with AFGL’s 
LOWTRAN 4 and other local thermal equi¬ 
librium models below 40 km. From 40 to 15 
km, several near infrared spectra of aerosol 
scattering were obtained on each of the four 
sunlit scans. These data will be used in 
conjunction with simultaneous photometer 
measurements to update the FLASH 
Monte Carlo scattering code. 



The spectrum of the earth limb at night taken 
by SPIRE at a 40 km tangent altitude. 


Auroral Studios: The first infrared emis¬ 
sion measurements (1.5 to 23 /xm) of the 
atmosphere above 50 km had been obtained 
by rocket probes in 1972. These experi¬ 
ments were launched out of Poker Flat, 
Alaska, under an AFGL/DNA sponsored 
program called ICECAP (Infrared Chem¬ 
istry Experiments for the Coordinated 
Auroral Program). This program obtained 
auroral enhancements at 2.8 and 5.3 /xm 
from nitric oxide, and 4.3 pirn emission from 
carbon dioxide. Analysis indicates that the 
observed temporal and spatial behavior of 
the 4.3 /xm auroral radiation can be ex¬ 
plained by a mechanism involving vibra¬ 
tional excitation of nitrogen by direct elec¬ 
tron impact, followed by a collisional reso¬ 
nance vibrational transfer to excite carbon 
dioxide, followed by emission by the carbon 
dioxide at 4.3 /xm. This mechanism is com¬ 


plicated by repeated transfers of the vibra¬ 
tional energy back and forth between nitro¬ 
gen and carbon dioxide, and by repeated 
absorption and emission by the carbon 
dioxide, which is optically thick enough 
below 90 km to ensure that the 4.3 /xm radia¬ 
tion will be absorbed and re-emitted many 
times as it escapes from the atmosphere. 
Another significant result caused by the ab¬ 
sorption and re-emission of all the radiation 
is that the time response for the auroral 4.3 
/xm emission is of the order of 5 to 10 min 
after the electron deposition. 

To test further the complex 4.3 /xm radi¬ 
ation transport theory, an auroral dynamics 
experiment was conducted on 26 October 
1978. Two rocket probes, one carrying the 
most sensitive cryogenic radiometer yet 
built and one monitoring the auroral particle 
flux and local electron density profile, were 
launched into and over a bright stable 
auroral arc. The first probe carried three 
co-aligned radiometric channels: 4278^ for 
instantaneous energy deposition, 2.7 /xm for 
OH airglow and NO overtone (auroral 
produced), and 4.3 /xm for CO 2 (ia) emis¬ 
sion. In addition, supporting ground based 
optical data and incoherent back-scatter 
radar measurements were made. 

The 4278 A (N 2 + first negative band, 0-1) 
photometer measurements showed that the 
rocket instruments were viewing a fairly 
bright auroral region throughout the entire 
rocket ascent. The precessional motion of 
the rocket axis caused maxima to be ob¬ 
served at 78, 98, and 112 km, where the 
rocket axis swung through nearest the 
direction of the brightest portion of the arc. 
The magnitude of the first two maxima of 
about 3 kR would correspond to a 5577 A 
auroral intensity of around 20 kR. The slight 
drop off with altitude and much less varia¬ 
tion with respect to rocket precessional 
motions indicate that the rocket was ascend¬ 
ing through some of the auroral deposition 
region vertically, and at the same time was 
moving into the brighter region due to the 
horizontal motion of the rocket. The ob¬ 
served intensity of over 2 kR at apogee indi- 




i 


192 


cates that a substantial portion of the aurora 
still remained above the rocket. The prelim¬ 
inary results from the Chatanika radar ; ndi- 
cate that the auroral deposition region was 
relatively high (around 120-km peak). On 
descent the rocket passed through the main 
arc region horizontally with a drop off of 
intensity at about 102 km. At 95 km the 
descent value was an order of magnitude 
lower than that on ascent. 

The measured ascent profiles of the 2.7 
jim emission generally follow the energy 
deposition as monitored by the 4278 A 
photometer. The region up to about 90 km 
shows a fall-off of about a factor of 2 super¬ 
imposed on a structure very similar to the 
photometer data. The descent 2.7 jxrn data 
also show structure closely related to the 
4278 A results except the region below 90 
km looks like the ascent 2.7 /urn data. 

Comparison with the equivalent N 2 * 3914 
A emission, which is commonly used to 
indicate the instantaneous energy deposi¬ 
tion, gives a ratio of about 7 photons of 2.7 
jim per photon of 3914 A emission. This 
value is nearly independent of altitude 
above 85 km. On an energy basis this means 
that about equal energy is converted to the 
2.7 jim band and the 3914 A band over the 
range from 85 to 122 km. 

The measured ascent 4.3 jxm profile rad¬ 
iation, in general, does not follow the in¬ 
stantaneous energy deposition as monitored 
by the 4278 A photometer. At 100 km the 
ascent zenith radiances of the 4.3 jim emis¬ 
sion are nearly an order of magnitude 
brighter than measured on rocket descent 
with the two profiles converging below 85 
km. 

A quick comparison of these results with 
previous investigation indicates that at 95 
km, the intensity on ascent would lie be¬ 
tween the value found on an IBC 11+ 
auroral arc and quiet values, whereas the 
descent value was near that of the quiet 
background. 

The first high resolution spectra of an 
auroral event were obtained by the cryo¬ 
genic interferometer-spectrometer, 


tariiiftGTH nie»0M(n«i 



Atmospheric spectra obtained by HIRIS on 
the upleg from 99 km altitude (105 seconds 
after launch) with the sensor viewing at an 
elevation of approximately 45 degrees (from 
horizontal). The obvious spectral features are 
due to the 15 /im m fundamental of CO) at 2350 
wavenumbers. For presentation purposes 
there is a split scale at 700 wavenumbers; the 
left scale applies to the 15 fim CO< band which 
has a peak spectral radiance value of 83 x 10 
W em-sr wavenumbers for the Q branch and 
the right hand scale applies to the rest of the 
spectrum (700 to 2500 wavenumbers). 



"leai 1700 isoo 1900 iooo 

wavenumber 


A selected portion (160 wavenumbers to 2000 
wavenumbers, the fundamental Av= 1, region 
of nitric oxide) of two spectra obtained by 
HIRIS at approximately the same sensor al¬ 
titude, 98 km, and the same elevation angle, 15 
degrees, but observed at different times and, 
consequently, representing different auroral 
conditions. The lower spectrum was obtained 
during the upleg at 102 sec after launch (3 sec 
before the scan shown above) viewing at an 
azimuth angle of 64 degrees (northeast). The 
upper curve was obtained during the downleg 
(+255 sec) viewing an azimuth angle of 247 
degrees (southwest). 


W3-J9JS- UJ3/SM0* 01 









ii*w*. ------- -|| i i nni iim~ i nii iwiwpn 


193 


HIRIS. This rocket-borne sensor was 
launched into an auroral breakup from 
Poker Flat, Alaska, on April 1, 1976. The 
interferometer covered the spectral region, 
600 to 2500 wavenumbers with approxi¬ 
mately 2 wavenumber resolution. The flight 
was designed to view vertically from 96 km 
on the upleg to an apogee of 125 km and to 70 
km on the downleg. However, the attitude 
control system failed to hold the sensor in a 
vertical position after initiating a turnover 
command (the interferometer was inte¬ 
grated in a down-looking configuration). 
This resulted in the payload rotating at 10.5 
deg/sec and performing six full rotations, 
vertical to down-looking, during the flight. 

The auroral activity was documented by 
all-sky photographs obtained by the Uni¬ 
versity of Alaska, scanning and fixed 
photometers by Utah State University and 
bakkscatter radar (Chatanika site) by Stan¬ 
ford Research Institute. These diagnostic 
data clearly show a Class III arc (100 kR) in 
the field of view during the time of the 
downleg spectrum (viewing southwest). 
The conditions for the upleg data show a 
more patchy auroral environment with less 
electron deposition occurring in the line of 
sight. The previously reported auroral en¬ 
hanced infrared emissions did not cover the 
wavelength region beyond about 5.3 p.m and 
were of too low resolution to identify NO 
uniquely as the principal radiator. 

Two spectra obtained near 98 km and 100 
km were analyzed to obtain relative NO(v) 
popuwations and estimates of NO(Av=l) 
fluorescence efficiencies. The vibrational 
population distributions were derived by a 
spectral simulation technique using a least 
squares method to determine the best 
match between computed and measured 
spectra. Because of the high resolution of 
the measurement, the accuracy of the line 
frequency calculation was carefully estab¬ 
lished. 

The derived vibrational population dis¬ 
tributions were found to be non-Boltzmann 
with pronounced local minima at v = 2 and 
exponential “tails” (v = 3-6) characteristic 


of temperatures of 2500 to 3500 K. The 
rotational temperature was determined to 
be approximately 235 K, which is repre¬ 
sentative of the local kinetic temperature at 
approximately 100 km. Populations of 
vibrational levels above v=6 could not be 
determined due to the noise level of the 
measurements. 

The integrated NO (Av=l) band inten¬ 
sities for the two data sets were used to 
deduce NO (v) column densities along the 
line of sight and fluorescence efficiencies for 
the fundamental band. The fluorescence 
efficiencies estimated from the two scans 
are in fair agreement in view of the con¬ 
siderable variations of auroral intensity 
sampled by the detector during each scan; 
the preliminary results indicate that, at alti¬ 
tudes near 100 km, roughly, 2 to 5 NO 
(Av=l) photons are emitted per ion pair 
formed in the aurora. 

A group of optical instruments for air¬ 
craft-based auroral measurements consist¬ 
ing of a multiple field infrared radiometer, a 
scanning photometer, and a low light level 
television is scheduled for installation into 
the NKC-135 Infrared Flying Laboratory in 
March 1979. This new system will enable 
spatially correlated visible and infrared 
measurements of infrared and visible 
aurora at a footprint size of 0.5 km. The 
infrared radiometer has a detector and 
optical system cooled by liquid nitrogen and 
a window and baffle which is cooled and 
flushed by cold nitrogen gas. This results in 
an order of magnitude increase in sensitiv¬ 
ity compared to instruments with warm 
optics flown previously. 

The data from these visible and infrared 
instruments will be used to determine the 
spatial and temporal characteristics of infra¬ 
red aurora at selected wavelengths and to 
determine the spatial and temporal correla¬ 
tion between infrared and visible aurora. 

The development of a totally liquid nitro¬ 
gen cooled Michelson interferometer has 
continued and the installation of a vibra- 
tionally isolated nitrogen cooled interfero¬ 
meter into the aircraft is scheduled for early 


1980. This will enable spectral meas¬ 
urements of auroral emissions out to 5.5 
/am. 

EXCEDE: The AFGL/Defense Nuclear 
Agency program called EXCEDE uses 
rocket-borne electron accelerators to simu¬ 
late atmospheric processes induced by the 
deposition of energetic electrons as in 
auroras and high altitude nuclear detona¬ 
tions. The primary scientific interest is the 
investigation of the detailed production and 
loss processes of various excited electronic 
and vibrational states resulting in optical 
and infrared emission as energetic primary 
electrons and their secondary and all subse¬ 
quent generation electrons are stopped in 
the atmosphere. The EXCEDE experiment 
uses pulsed rocket-borne electron accele¬ 
rators with well-defined excitation condi¬ 
tions of electron energy and power, deposi¬ 
tion volume, deposition altitude and dosing 
duration to provide measurements of time 
dependent optical and infrared emissions 
which are interpreted in terms of chemical 
processes, reaction rates, and photon 
yields. These data are utilized in various 
computer codes to calculate optical/infrared 
backgrounds for auroral and nuclear dis¬ 
turbed atmospheres. The codes assess the 
effects of enhanced atmospheric back¬ 
grounds on optical and infrared systems. 

On December 13, 1977, PRECEDE II, 
one of a series of artificial auroral exper¬ 
iments in the EXCEDE program, was 
launched from the White Sands Missile 
Range, New Mexico, at 05:50 UT. 
PRECEDE II was designed to serve as an 
engineering test of an electron accelerator 
module providing a pulsed 3 kV, 7 A elec¬ 
tron beam, to provide an engineering test 
for a newly designed liquid nitrogen cooled 
rocket-borne infrared Michelson interfer¬ 
ometer, and to observe the ultraviolet and 
visible emissions induced in the night sky by 
the rocket-borne electron source with a 
number of ground based imaging, spectro- 
graphic, and photometric instruments. The 
accelerator, 38 cm in diameter, 91 cm long, 
and weighing 160 kg, w r as designed to pro¬ 


PRECEDC 1 ■ SEOOSS IMA8ES 


ALTITUDE, 94 M. DESCENT : ACCELERATOR POWER, I0«w 
(TIMES ERDM THE START OF THE ACCELERATOR PULSE ARE INDICATED I 



Itiiiigrs of the electron induced optical emis¬ 
sions induced in the night atmosphere by the 
rocket-borne electron accelerator in the 
PRECEDE II artificial auroral experiment. 

The emission developing slowly after the ac¬ 
celerator is pulsed on and persisting after the 
accelerator is pulsed off at 4.3 seconds is due to 
the lorg lived 0( 'S> auroral green line. 

vide a 20-kW beam of 3-kV electrons. A 
pulse period of 6 sec composed of a 4.3-sec 
beam on and a 1.7 sec beam off component, 
was intended to be repeated for the duration 
of the experiment, anticipated to be on the 
order of 3 min, assuming nominal rocket 
performance. The PRECEDE II launch 
w r as designed, in part, as an engineering 
test of a prototype electron accelerator 
module to be used on the subsequent 
EXCEDE spectral experiment. The accel¬ 
erator used two tungsten filaments directly 
heated to approximately 2800 K. 

The accelerator door was opened, fila¬ 
ments heated and high voltage applied 108 
sec after launch, at an upleg altitude of ap¬ 
proximately 83 km. The accelerator arced 
due to high voltage breakdown within the 
accelerator structure for approximately 30 
sec, until the payload achieved an altitude of 
97 km at 138 sec after lift-off. A latch-out 
protection circuit limited the maximum 
energy dissipation during the arcing and 
prevented catastrophic failure due to fusing 






196 


of any accelerator components. At approx¬ 
imately 138 sec after launch, the accelerator 
produced a 4.3-sec pulse of 3-kV electrons 
depositing 20 kW into the night atmos¬ 
phere. The electron induced ultraviolet and 
visible emissions were readily recorded by 
the ground based optical instruments which 
included film cameras, telephotometers, 
and image intensified spectrographs. 

The accelerator power output showed 
slight loading characteristics during a given 
pulse and the power output decreased from 
approximately 20 kW at 138 sec after launch 
(97 km on payload ascent) to approximately 
13 kW at 212 sec (95 km on payload descent). 
At lower descent altitudes, the accelerator 
continued operation, pulsing sporadically 
and providing an electron beam of several 
kilowatts to a descent altitude of approxi¬ 
mately 64 km. The PRECEDE II rocket 
flight was a severe test of an accelerator 
module to be launched on the EXCEDE 
SPECTRAL experiment. 

The two major innovations in the pro¬ 
posed EXCEDE SPECTRAL experiment 
are: (1) a significant increase in the power of 
the rocket-borne electron accelerator; and 
(2) the addition of optical and infrared spec¬ 
tral instruments to record detailed band 
profiles rather than photometric and 
radiometric instruments that isolate specific 
wavelength intervals as used in the earlier 
launches. The proposed nominal electron- 
accelerator power is 120 kW (3 kV, 40 A) 
using 4 electron-gun modules each provid¬ 
ing a 10 A beam. Rocket-borne spectral 
instrumentation includes two grating spec¬ 
trometers, a Michelson interferometer 
using liquid nitrogen cooled optics to pro¬ 
vide the minimal detectable radiance as 
limited by thermal emissions of the instru¬ 
ment and two circular variable filter spec¬ 
trometers operating at both liquid nitrogen 
and liquid helium temperatures. The optical 
bandwidth of the spectral sensors extends 
from approximately 0.15 to 25 /xm. The 
EXCEDE SPECTRAL experiment is ex¬ 
pected to provide sufficient resolution to 
identify uniquely the species emitting in the 


UV, visible and IR under experimental 
conditions that simulate auroral and nuclear 
disturbed atmospheres. 



Payload orientation for the EXCEDE 
SPECTRAL experiment with only electron 
gun module 3 shown operating. The attitude 
control system maintains the indicated posi¬ 
tion in pitch, yaw and roll for the duration of 
the experiment. 

Analysis of the time dependent O CS) 
5577 A emission induced in the night 
atmosphere by a pulsed rocket-borne elec¬ 
tron accelerator in the initial EXCEDE 
launches has been completed. Energy 
transfer from the N 2 (A 'Su + ) state to O( 'P) 
is the principal O('S) production process in 
the 95- to 160-km altitude range, accounting 
for as much as 75 percent of the total O('S) 
production at some altitudes. The O('S) 
production and loss processes inferred from 
the EXCEDE experiments have been used 
to compute the time dependent 0( 'S) auro¬ 
ral emission rate as a function of altitude in a 
model aurora. The accurate reproduction of 
auroral O('S) emission rates by the model 
calculations is considered a significant test 
of validity of the O('S) production and loss 
processes determined in the initial EX¬ 
CEDE launches. 

Optical Infrared Code (OPTIR): A com¬ 
puter code and modeling effort, OPTIR, 
describes the optical infrared characteris- 



196 


tics of natural and high energy sources in 
the atmosphere. The code is particularly de¬ 
signed to model nuclear detonations in the 
atmosphere and predict their effects on 
optical/infrared systems. Modular sub¬ 
elements of the OPTIR code have been 
adapted for specific radiation and energy 
deposition applications, such as low-altitude 
burst signatures (TACTIR), auroral depo¬ 
sition and radiative characteristics 
(OPTAUR), and observations by surveil¬ 
lance systems (SIMDRIV). 

Computer code models have been devel¬ 
oped for infrared radiation sources in the 2.0 
to 5.0 /xm region arising from nuclear bursts 
in the atmosphere. Such models include the 
infrared chemistry sources in regions af¬ 
fected by the passage of strong shocks, 
thermal pulse output from nuclear fireballs 
and spatio-temporal variations in emissions 
from beta tubes. Scaling laws of fireball sig¬ 
natures in the visible and infrared spectrum 
as a function of wavelength and time after 
burst have been developed. The OPTIR 
capability has been used effectively in pro¬ 
grams to determine the nuclear effects on 
optical/infrared systems. 

Instrumentation Development: De¬ 
tailed knowledge of the spectral character¬ 
istics of background radiation and of at¬ 
mospheric emission and absorption is re¬ 
quired to design high sensitivity sensors for 
optimum performance. Concurrently, 
research on techniques to enhance the sensi¬ 
tivity of sensors is being performed. Multi¬ 
plex/high-throughput techniques can yield 
the required detailed spectral information 
and, at the same time, be used to develop 
more sensitive sensors. 

Research is being carried on leading to 
the development of a state-of-the-art high 
resolution (0.1 wavenumber) cryogenic 
interferometer for field measurements. 
New techniques, such as the Spectrometer 
Interferometer with Selective Modulation 
(SIMS being its French acronym), are being 
studied. The potential of this technique lies 


in the fact that the spectrum is obtained 
directly without Fourier transformation, 
while still using a scanning interferometer 
of high throughput. It also should prove to 
be a more stable instrument since the two 
interfering beams use the same optical com¬ 
ponents. 

The new AFGL facility, called COCHISE 
iCold Chemi-excited Infrared Simulation 
Experiments), implements detection tech¬ 
nology and concepts initially developed for 
space surveillance systems, achieves infra¬ 
red detection sensitivities up to six orders of 
magnitude better than available in any 
other laboratory, and concurrently provides 
a truly novel low-pressure, “wall-less” capa¬ 
bility for simulation and study of high- 
altitude phenomena. Experiments are con¬ 
ducted entirely within a large cavity held at 
20 K by a closed-cycle gaseous helium re¬ 
frigeration system. Part of the refrigeration 
capacity is also used to provide a cryo- 
pumping capability within a closely temper¬ 
ature-controlled reaction chamber located 
inside the large 20 K cavity; an infrared 
scanning monochromator also stationed in 
the 20 K environment measures the radia¬ 
tion produced by processes occurring in the 
cryo-pumped hyper-fast-flow reaction vol¬ 
ume. By reducing to a totally negligible 
level the thermal background radiation, an 
IR detectivity has been achieved which per¬ 
mits the observation of emissions from ex¬ 
cited species with number densities as low 
as 10" cm Operation of the facility is aug¬ 
mented by an unusually large and complex 
minicomputer system which executes au¬ 
tomatically a multitude of control, measure¬ 
ment, and analysis tasks; the computer 
system is hard-wired to and totally dedica¬ 
ted to support of the COCHISE facility. 

In initial applications, experiments have 
been conducted by mixing the products 
from a synchronized set of electrodeless 
microwave discharges with non-excited tar¬ 
get gases; with a contact time well under 
one msec, the radiation observed is repre¬ 
sentative of the initial undisturbed product 


197 


molecule vibrational distribution, A quanti¬ 
tative definition of the IR photon yield from 
chemi-excited nitric oxide produced by 
N(-D) + O 2 has been completed and it has 
been established that 27 percent of the en¬ 
ergy released in this reaction is converted to 
vibrational excitation of the NO product 
molecule. By experimentally defining the 
quantum details of the process, which pro¬ 
duces IR radiation in the 2.7- and 5.3-^m 
regions, its altitude dependence in the at¬ 
mosphere has also been determined. Data 
have also been collected in the COCHISE 
program which begin to define the extent to 
which the 10- to 12 -fim atmospheric 
“window” can be degraded by ozone infra¬ 
red emission; in this case, it is the recombin¬ 
ation of atomic oxygen (via the process 0 + 
O 2 + M—» O 3 + M, yielding vibrationally 
excited ozone) which is being subjected to 
scrutiny. 

Development of ultraviolet resonance ab¬ 
sorption and tunable laser diagnostics for 
ionic and non-radiating species is well under 
way. This step will substantially enhance 
the value of COCHISE for a broader range 
of problems. 


IR Emission from Electron Excited Air: 

Electron excitation and subsequent energy 
transfer processes by atmospheric species 
occur in the upper atmosphere either natur¬ 
ally as in the aurora or following a high 
altitude nuclear event. Detailed information 
concerning these exchange processes, 
which control the radiative state of the at¬ 
mosphere, are obtained by using our labora¬ 
tory simulation facilities and measuring the 
visible and infrared emission produced by 
energetic electron irradiation of atmos¬ 
pheric gases. Excitation is accomplished by 
electrically pulsing an electron beam of 0-20 
mA over a 5000 to 50,000 V energy range 
into a target chamber containing atmos¬ 
pheric gas mixtures at pressures of 
1/1,000,000 to 1 atmosphere. 



- 

■i 


Seale drawing of COCHISE facility chamber; 
overall length is nearly 11 feet. Only the major 
components are shown here. System cooling is 
provided by a 0.5 kw closed-cycle gaseous 
helium refrigerator. 

Recent experiments have concentrated 
on determining the dynamic behavior of ex¬ 
cited gases by observing the evolutionary 
history of the radiation produced during and 
after electron impact. The measurement 
technique of Fourier Time Resolved 
Spectroscopy is used to obtain the time de¬ 
pendence of the infrared emissions. This 
technique, developed at AFGL, is based on 
time gating the signal of a Michelson inter¬ 
ferometer-spectrometer at corresponding 
sampling positions of the interferometer 
stroke to obtain a series of time sequenced 
interferograms. Fourier tranformation of 
the series of interferograms gives the entire 
infrared radiation evolution of the excited 
gas. 

Typically, the radiation to be observed is 
weak; hence, the throughput and multiplex 
advantages of Fourier interferometry are 
essential to perform the required spectral 
measurements. The capability of our time- 
resolved technique has been improved by 
utilizing a minicomputer to control the ex¬ 
periment and record the interferograms. As 
the interferometer mirror is scanned, its 
motion dictates both the computer process¬ 
ing and interferogram recording. With this 
arrangement the ultimate time resolution 





m 


k 

r 


achieved is the limit of the response time of 
the infrared detector. 

A background optical suppression scheme 
(BOSS), conceived at AFGL, is being pur¬ 
sued for use in various applications. It has 
the potential of allowing the detection and 
spectral signature measurements of faint 
targets immersed in interfering background 
radiation. Laboratory data have been ob¬ 
tained which demonstrate a background 
suppression ratio of about two orders of 
magnitude. 

Several highly sophisticated laboratory 
measurement efforts support and add to the 
extensive field measurement and modeling 
programs discussed. These include high res¬ 
olution spectral measurements of molecular 
parameters, study of specific atomic and 
molecular excitation processes responsible 
for infrared emission in the upper atmos¬ 
phere, infrared emission from molecules 
excited by electrons, and investigation of 
high velocity collisions between gaseous 
species. Such basic research studies provide 
the data fundamental to our scientific under¬ 
standing of the measurements on atmos¬ 
pheric IR transmission and emission (back¬ 
grounds) and particularly to the develop¬ 
ments of the codes and models describing 
these atmospheric phenomena. 

Cryogenic IR Cheml-Excitation Ex¬ 
periment*: The laboratory has built and is 
now operating an awesome new exper¬ 
imental facility to study specific atomic and 
molecular excitation processes which are 
important sources of atmospheric IR radia¬ 
tion, and which could compromise the per¬ 
formance of DoD IR surveillance systems. 
Detailed definitions of the microscopic proc¬ 
esses which control production and relax¬ 
ation of energetically excited species are re¬ 
quired, to make reliable predictions and 
assessments of atmospheric radiation per¬ 
turbations resulting firom natural and arti¬ 
ficially induced atmospheric disturbances. 
The long radiative lifetimes typically asso- 



A double beam scheme applied to Michelson 
interferometer to nullify the effects of win¬ 
dows. The beam labeled 1 contains wanted 
information, the absorption spectrum of the 
discharge, plus a contribution from the cell 
windows which is not wanted. The portion 
reflected upwards at the dielectric beam 
splitter differs in phase by n from the portion 
transmitted forward. Another beam, contain¬ 
ing only the unwanted cell spectrum is re¬ 
flected by mirrors and brought to the beam 
splitter on its other side. The portion reflected 
to the right undergoes a phase change of it and 
so is out of phase with the contribution coming 
from the discharge and if the amplitudes are 
adjusted properly, will cancel out the cell 
signal. Similarly, the upwards going beams 
are also in anti-phase. The final beam, 2 is thus 
free of the effects of the cell, and contains the 
absorption of the gas only. 


dated with molecular vibrational transi¬ 
tions demand that experiments be operated 
at pressures low enough to simulate upper 
atmosphere densities and simultaneously 
not be compromised by spurious surface ef¬ 
fects such as wall collisions. 

Time-resolved infrared measurements 
have been performed on carbon dioxide and 
various gas mixtures subjected to electron 
bombardment. Fluorescence of the gas mix¬ 
tures in the 3 to 6 /nm spectral region is 
predominantly due to the carbon monoxide 
fundamental bands up to the nineteenth vi¬ 
brational level and the fundamental 4.3 /±m 
band of carbon dioxide. By employing the 





199 


electron beam in a short pulse, low duty 
cycle mode, the rise and decay behavior of 
the spectrally resolved fluorescence has 
been determined. Observation of the global 
radiative spectrum hits proved invaluable in 
determining and quantifying the relevant 
electron, ionic and neutral chemical kinetics 
occurring in the irradiated system. Speci¬ 
fically, it has permitted the origin of highly 
excited carbon monoxide to be determined, 
that is, ionization of carbon dioxide followed 
by disassociative electron recombination. 
Based on the known energy input, the fluo¬ 
rescence measurements show that 5 percent 
of the energy deposited in the gas appears 
as excited carbon monoxide with, on the 
average, one vibrationally hot molecule 
being produced per ion pair. The decay of 
the infrared emission is characterized by 
relaxation rate constants with a vibrational 
quanta being communicated in a step-down 
process from carbon monoxide to carbon 
dioxide. The rate constants for sixteen 
levels have been determined from data col¬ 
lected. Additionally, experimentally deter¬ 
mined values for the fundamental Einstein 
coefficients for emission have been obtained 


•'Ml W PINO* NT I MISSIONS Of 
KIv'RON iRRADlATfO liASE S 



Excitation buildup observed during electron 
pulse. The pulse (32 kV, 1 ma) is terminated 
after 4 msec. The buildup of CO in the region 
2250 to 1800 wavenumbers, and CO 2 in the 
region 2400 to 2300 wavenumbers is clearly 
shown. 


1 1 Ml (XPtMKNT l MISSIONS L* 
ELECTRON IRRADIATE U OASES 


ICO, *OA 



Decay of excited species observed after pulse 
termination. The decay of the vibrationally hot 
CO (T v approximately 20,000 K) and CO 2 may 
be followed as a function of time and vibra¬ 
tional level. 


on levels seven through twelve. This is the 
first determination by direct measurement 
and the values appear to be in good agree¬ 
ment with theoretical estimates. 

A major effort has been directed toward 
determining the mechanisms responsible 
for producing 2.7 pm radiation in the quies¬ 
cent and aurorally disturbed atmosphere. 
The generally accepted thesis is that a ma¬ 
jority of emission is due to the first overtone 
vibration rotation bands of nitric oxide. Sev¬ 
eral sets of measurements by various at¬ 
mospheric probes are known to be inconsis¬ 
tent with the nitric oxide model. Ratios of 
emission between the fundamental and first 
overtone bands appeared too small and car¬ 
bon dioxide combination band emission was 
offered as an explanation. This possibility 
has been explored in our laboratory by spec¬ 
trally resolving the 2.7 p.m emission pro¬ 
duced by electron irradiated air which con¬ 
tains carbon dioxide and comparing similar 
measurements performed on air from which 
the carbon dioxide has been removed. Spec¬ 
tral measurements established that the 
combination bands are l/25th as strong as 





200 


the 4.3 band, and, hence, are not 
responsible for the observable emission at 
the shorter wavelength. The laboratory 
measurements also show that the nitric 
oxide formed is highly excited and suggests 
that a possible explanation of the observed 
anomaly is due to incorrect transition prob¬ 
abilities or hydroxyl emission. 

To study the IR emission at longer wave¬ 
lengths (5 to 25 /am) and lower pressures, a 
large tank, 4 1/2 feet in diameter and 15 feet 
in length, is used. At these wavelengths, 
the emission by the room surroundings is 
larger than that produced by electron excit¬ 
ation of the experimental gases. To over¬ 
come this thermal background, the entire 
internal surface of the tank, transfer optics 
and IR instrumentation are cooled to liquid 
nitrogen temperatures. With this added 
temperature control, the sensitivity of the 
measurements is effectively increased by 
one thousand or more, and measurements 
which were previously impossible are now 
possible. 

Molecular Beam Studiea: High velocity 
collisions occurring at high altitudes (above 
300 km) between plume and atmospheric 
gaseous species are investigated in the 
molecular beam facility. At these altitudes 



The LABCEDE tank showing the liquid 
nitrogen lines and controls. 


the main atmospheric species is atomic 
oxygen. For lower altitudes, interaction 
with molecular nitrogen and oxygen become 
significant. Consequently, the experimental 
efforts are directed toward production of 
fast beams for the species 0, N 2 and O 2 . For 
the permanent gases N 2 and O 2 , the beam 
production technique used is the well-estab¬ 
lished method of isentropic expansion of a 
gaseous mixture from a heated supersonic 
nozzle. Beam velocities and their speed dis¬ 
tributions are studied by time of flight meas¬ 
urements. Beam intensities of 5 x 10parti¬ 
cles per steradian per second are readily 
achieved. In the early stages of this pro¬ 
gram, the plume particles (CO 2 and CO) 
were introduced into a gold-plated integra¬ 
ting sphere where they interacted with fast 
beams of N 2 or O 2 . As reported, no signals 
were observed in this preliminary warm 
background experiment. Analysis showed 
that background temperature had to be con¬ 
siderably lowered to achieve higher signal- 
to-noise ratios. The major improvements 
undertaken were design and construction of 
a new liquid nitrogen cooled collision 
chamber, design and construction of a 2.4 to 
4.8 fim CVF-spectrometer, and introduc¬ 
tion of the target gases CO 2 and others in 
the form of another molecular beam flowing 
opposite to the fast beam of atmospheric 
species, in the so-called 180 degree geom¬ 
etry. These major improvements have 
finally been incorporated in the molecular 
beam facilities and the apparazus is now 
operational and producing significant meas¬ 
urements. Emission from CO 2 in the 4.3-pim 
band spectral region has been recorded fol¬ 
lowing vibrational excitation of the 03 mode 
of CO 2 by molecular oxygen and nitrogen in 
an elastic collision with relative velocity 
ranging from 2 to 4.2 km/sec. Spectra have 
been obtained at all these velocities and data 
have been analyzed to obtain the extent of 
the rotational excitation in the observed 
modes and to extract cross sections for the 
collisions. 

For the study of the atomic oxygen col¬ 
lisions, a new beam source utilizing DC arc 






201 


heating and isentropic expansion was 
designed and its construction is almost com¬ 
plete. After installation and diagnostics 
measurements, the reactions of CO 2 and 
H 2 O with 0 atoms will be studied in detail. 

Molecular Spectroscopy: A substantial 
laboratory program aimed at measuring the 
spectral parameters of atmospheric gases 
includes high resolution laboratory data on 
H 2 O, CH 4 and CO 2 using a 2-meter path 
difference interferometer-spectrometer. 
Data have been obtained at room and at 
elevated temperatures. Upon analysis of 
such spectra, any discrepancies between 


calculations and measurements can be used 
to determine an improved spectroscopic 
dataset. In addition, absorption data at 0.01 
wavenumber resolution at 625 K were 
obtained. This high-resolution facility is 
being modified to allow the measurement of 
high resolution (0.005 wavenumber) spectra 
up to flame temperatures around 2400 C. 
High-resolution (0.1 wavenumber) strato¬ 
spheric emission data of dominant and trace 
constituents will be obtained in future bal¬ 
loon flights using an advanced state-of-the- 
art interferometer. These measurements 
are being made to upgrade the HITRAN 
transmission model. 


1 

i> 

1 


1 

•1 

4 

i 


JOURNAL ARTICLES 
JULY 1976 • DECEMBER 1978 


Cress, T. S., and Fenn, R. W. 

Climatology of Atmospheric Aerosols in Europe: 
Project OPAQUE 

Proc. ofSPIE Tech. Symp., Opt. Properties of the 
Atm., Vol. 142 (April 1978) 

CUNNIFF, C. V. 

Cleaning Procedures for the AFGL Infrared Survey 
Experiments 

Opt. Engrg., Vol. 16(1977) 

Gibson, F. W. 

A Rare Event in the Stratosphere 
Nature. Vol. 263, No. 5577 (7 October 1976) 

In Situ Photometric Observations of Angular 
Scattering from Atmospheric Aerosols 
Appl. Opt., Vol. 15(October 1976) 

GlRNIUS, R. J., (Unto. ofWisc., Madison, Wise.), 
FAIRBAIRN, A. R., and WOLNIK, S. J. 
Infrared Radiation Facility for Upper Atmospheric 
Physics 

Bull, of Am. Phys. Soc., Vol. 23(1978) 

KENNEALY, J. Py Delgreco, F. P., 
Caledonia, G. E., and Green, B. D. (Phys. 
Sci., Inc., Woburn, Mass.) 

Nitric Oxide Chemi-excitation Occurring in the 
Reaction Between Metastable Nitrogen Atoms and 
Oxygen Molecules 

J. of Chem. Phys., Vol. 69, No. 4 (15 August 1978) 


KENNEALY, J. P., and MOORE, W. M. 

A Numerical Method for Chemical Kinetics Modeling 
Based on the Taylor Series Expansion 
J. of Phys. Chem., Vol. 81, No. 250977) 

Kneizys, F. X. 

Atmospheric Transmittance and Radiance: The 
LOWTRANCode 

Proc. of Soc. of Photo-Opt. Instmn. Engrs., Vol. 142 
(1978) 

McClatchey, R. A. 

Tra remittance Functions for Remote Sensing 
Proc. of the Symp. on Radn. in the Atm. 1976, 
Garmisch-Partenkirchen, Germany (1977) 

McClatchey. R. A., Fenn, R. W., 
Selby, J. E. A., Volz, F. E., andGARiNG, 
J.S. 

Optical Properties of the Atmosphere 

Chap. 14, Handbook of Opt., Spons. by Opt. Soc. of 

Am., Ed. by W. G. Driscoll, Publ by McGraw-Hill 

(1978) 

McClatchey, R. A., Kelley, P. L., <mit 

Lincoln Lab, Lexington, Mass.) LONG, R. K., (Ohio 
State Univ.) and SNELSON, A. (IIT Res. Inst., 
Chicago, Ill.) 

The Molecular Contribution to the Infrared Laser 
Transmittance of the Natural Atmosphere 
Opt. and Quantum Elect., Vol. 8(1976) 

McClatchey, R. A., andSHETTLE, E. P. 

Atmospheric Optical Transmission Modelling and 
Prediction Schemes 

AGARDConf. Proc. No. 238, Operational Modelling of 
the Aerospace Propagation Environment (November 
1978) 


t 

% 


'1 



202 


Miranda, H. A., Jr, (Epsilon Labs Inc., 
Bedford, Mass.), and DEARBORN, F. K. 

Altitude Profiles of Atmospheric Aerosols Obtained 
urith the Epsilon/AFGL Balloon-Borne Sizing 
Spectrometer 

Proc. of Topical Mtg. on Atm. Aerosols, Their Opt. 
Properties and Efif., NASA CP-2004 (13-15 December 
1976) 


MuRCRAY, F. H., MuRCRAY, D. G. (Univ.of 
Denver, Colo.), SNIDER, D. (Atm. Sci. Lab., White 
Sands Missile Range, N. M.), and McCLATCHEY, 

R.A. 

COi Radiant Temperature Measurements 
NASA Tech. Rpt., “Stratcom-VIII Tech. Paper (31 
December 1978) 


Murdock, T. L., and Price, S. D. 

Infrared Emission from the Interplanetary Dust 
Cioud 

Bull, of Am. Astronom. Soc., Vol. 10, No. 2(June 1978) 

Murphy, R. E. 

Measurements of Infrared Transient Phemmiena 
Spectrometric Techniques 

G. Vanasse, Ed., Academic Press, Vol. 1, Ch. 6(1977) 

Murphy, R. E., Rogers, J. W., Cook, F. 

H. , and Caledonia, G. E. (Phys. Sci., inc. 
Wobum, Mass.) 

Fmirier Spectroscopic Measurements of Transient CO 
Emissions 

J. of Opt. Soc. of Am., Vol. 61, No. 2(1977) 

Murphy, R. E., and Sakai, H. 

Improvements in Time Resolved FourierSpectroscopy 
Appl. Opt., Vol. 17(1 May 1978) 

Nadile, R. M., Wheeler.N. B.,Stair, 
A. T., JR., and FroDSHAM, D. G., and 
Wyatt, C. L. (Utah State Univ.) 

SPIRE — Spectral Infrared Experiment 
Modem Utilization of IRTechnol. Ill, Vol. 124 
(August 1977) 

O’NEIL, R. R., BlEN.F. (Aerodyne Res., Inc., 
Bedford, Mass.) BURT, D, (Space Sci. Lab., Utah 
State Univ.), SANDOCK, J. A., and STAIR, A. 
T., Jr. 

Summarized Results of the Artificial Auroral 

Experiment, PRECEDE 

J. of Geophys. Res., Vol. 83, No. A7 (July 1978) 

O’Neil, R. R., and Lee, E. T. P. 

EXCEDE Experiment: Ground Based 
Telephotometer Measurements ofNC IN S9I4 A and 
O('S) 5577A Emissions 

EOSTrans., Am. Geophys. Union, Vol. 58, No. 6(June 
1977) 


O’Neil, R. R., Shepherd, 0., Reidy, W. 
P., Carpenter, J. W. (Visidvne, inc., 
Burlington, Mass.), DaVIS, T. N. (Geophys. Inst., 
Univ. of Alaska), NEWELL, D., ULWICK, J. C., 
and Stair, A. T., Jr. 

EXCEDE II Test, An Artificial Auroral Experiment: 

Ground Based Optical Measurements 

J. of Geophys. Res., Vol. 83, No. A7 (July 1978) 

Pine, A. S., Dresselhaus, G., Palm, B. 

(MIT Lincoln Lab., Lexington, Mass.), DAVIES, R. 
W. (Ctr. for Atm. Res., Lowell Univ.), and 

Clough, S.A. 

Analysis ol the 4 fim(vi'in) Combination Band of SO* 
J. of Mol. Spectros., Vol. 67(1977) 

Price, S. D. 

The AFGL Infrared Celestial Survey Program 
Proc. of AIAA 4th Sounding Rocket Technol. Conf., 
23-25 June 1976 

Calibration of the AFGL Survey Instruments 
SPIE Proc., Utilization of IR Detectors, Vol. 132 
(1978) 

PRICE, S. D., andMARCOTTE, L. P. 

Infrared Observations of the Zodiacal Dust Cloud 
Bull, of Am. Astronom. Soc., Vol. 10, No. 2 (June 1978) 

Rogers, J. W., Stair, A. T., Jr., Degges, 

T. C. (Visidyne, Inc., Burlington Mass.)and 
Wyatt, C. L., Baker, D. J. (ElectroDyn. 
Labs., Utah State Univ.) 

Rocketbome Measurements of Mesospheric HtO in the 
Auroral Zone 

Geophys, Res. Ltrs., Vol. 4, No. 9(September 1977) 

Rogers, J. W., Stair, A. T., Jr., 
Wheeler, N. B., and Wyatt, C. L., 

BAKER, D, J. (Electrodyn. Labs., Utah State 
Univ.) 

Rocketbome Measurements of Atmospheric 

Emissions from 7 to -14 Micrometers 

EOS Trans., Am. Geophys. Union, Vol. 58, No. 6 (June 

1977) 

Rothman, L. S. 

Atmospheric Optics Technical Group Meeting 
Appl. Opt., Vol. 16, No. 2(February 1977) 

Update of the AFGL Atmospheric Absorption Line 

Parameters Compilation 

Appl. Opt., Vol. 17(15November 1978) 

High Resolution Atmospheric Transmittance and 
Radiance: HITRAN and the Data Compilation 
Proc. of Soc. of Photo-Opt. Instmn. Engrs,, Vol. 142 
(1978) 

Rothman, L. S. , and Benedict, W. S. (Inst. 

for Phys. Sci. and Technol., Univ. ofMd.) 

/ nfrartd Energy Levels and Intensities of Carbon 
Dioxide 

Appl. Opt,, Vol. 1705 August 1978) 





203 


Rothman, L. S., Clough, S. A., 
McClatchey, R. A., Young, L. G. (Phys. 

Dept., Texas A&M Univ.), SNIDER, D. E. (Atm. 
Sci. Lab., White Sands Missile Range, N. M.), and 
GOLDMAN, A. (Dept. ofPhys., Univ. of Denver, 
Colo.) 

AFGL Trace Gan Compilation 

Appl. Opt., Vol. 17, No. 4 (15 February 1978) 

Rothman, L. S., and McClatchey, R.A. 

Updating o) the AFCRL Atmospheric Absorption Line 

Parameters Compilation 

Appl. Opt., Vol. 15(November 1976) 

Sakai, H. 

High -Resolving Power Foil rier Spectroscopy 
Book, Speetrometrie Techniques, Ed. by G. Vanasse; 
Pub. by Acad. Press, Inc. (April 1977) 

Sakai, H., and Murphy, R. E. 

Improvements in Time Resolved Fwirier Spectroscopy 
Appl. Opt., Vol. 17 No. 9(1 May 1978) 

SHARMA, R. D., and HART, R. R. (Oakwood 
Sch., Poughkeepsie, N. Y.), 

Comparison of Distorted Wave and Close-Coupling 
Results For Scattering of HD by He at Thermal 
Energies 

J. ofChem. Phys., Vol. 69(1 August 1978) 

Shettle, E. P. 

Radiative Transfer in Rural, Urban and Maritime 
Model . 1 'niospheres 

Proc. of Topical Mtg. on Atm. Aerosols, Their Opt. 
Properties and Eff., NASA-CP-2004 (13-15 December 
1976) 

Effects of Humidity Variations on Atmospheric 

Aerosol Optical Properties 

Preprint Vol.: 3rd Conf. on Atm. Radn., 28-30 June 

1978, Davis, Calif., Pub. by Am. Met. Soc., Boston, 

Mass. 

Atmospheric Aerosol Estimates for Atmospheric 
Optical Models 

Proc. ofWkshp. on Remote Sensing of the Maritime 
Boundary Layer, Vail, Colo. (9-11 August 1976), NRL 
Memo. Rpt. 3430 (June 1977) 

Shettle, E. P., and Volz, F. E. 

Optical Constants fora Meteoric Dust Aerosol Model 
Proc. of Topical Mtg. on Atm. Aerosols, Their Opt. 
Properties and Eff., NASA CP-2004 (13-15 December 
1976) 


SHIVANANDEN, K., and Me NUTT, D. P., 

S aval Res. Lab., Wash., D. C.) PRICE, S. D., and 
URDOCK, T. L. 

Far Infrared Sky Survey Experiment 

Proc. of Soc. of Photo-Opt. Instmn. Engrs., Vol. 132 

(1978) 


Stair, A. T., Jr. 

Cryogenic Spectrometry for the Measu cement of 
Airglow and Aurora 

Proc. ofSoc. of Photo-Opt. Instmn. Engrs., Vol. 91, 
Methods for Atm, Radiometry, San Diego, Calif. (26-27 
August 1976) 

ULWICK, J. C., and BAKER, K. D. (UtahState 

Univ.) 

Measurements of Electron Density Structure in 
Striated Barium Clouds 

Geophys. Res. Ltrs., Vol. 5, No. 8 (August 1978) 

Vanasse, G. 

Data Compression forFmirier Spectroscopy 
Proc. of 1976 Conf. on Inf. Sci. and Sys., Dept, of Elec. 
Engrg., Johns Hopkins Univ., Baltimore, Md. (1976) 

Volz, F. E. 

The Kmkatoa Volcanic Turbidity— A Reassessment; 
Trend of Twilight Color Ratios and Converted LIDAR 
Data of the Fuego Dust Cloud 
Proc. of Mtg. on Atm. Aero., Their Opt. Properties and 
Eff., Williamsburg, Va„ NASA CP-2004 (13-15 
December 1976) 

Twilights at MLO and Samoa 
GMCC Ann. Rpt. (June 1978) 

Observations and Measurements of the Solar Aureole 
Infrared Characterization of Some Worldwide Aerosol 
Fractions 

Preprint Vol.: Third Conf. on Atm. Radn., Pub. by 
Am. Met. Soc. (28-30 June 1978) 

Young. L. D., Young, A. J. (Texas a&m 
U niv), Clough, S. A., and Kneizys, F. X. 

Calculation of Spectroscopic Data for the V=0 and 
V= I States of Nitric Oxide 

J. of Quantitative Spectros. and Radiative Transfer, 
Vol. 20(19781 

PAPERS PRESENTED AT MEETINGS 
JULY 1976 - DECEMBER 1978 

Baker, K. D. (Utah State Univ.), ULWICK, J. 
C. , and CLARK, J. (Def. Nuc. Agcy., Wash., D. C.) 
Rocket Measurements of Electron Density 
Irregularities in the Auroral Zone 
3rd Gen. Sci. Asbly. of Inti. Assoc, of Geomag. and 
Aeron., Univ. of Wash., Seattle, Wash. (22 August-3 
September 1977) 

Clough, S. A., Kneizys, F. X., 

Rothman. L. S., and Smith^H. S. P., 
Dube, D. J., Gardner, M. E. (Visidyne, 

Burlington, Mass.) 

A Fast Atmospheric Transmittance and Radiance 
Algorithm: FASCODE 

Opt. Soc. of Am., 1978 Ann. Mtg., San Francisco, Calif. 
(30 October - 3 November 1978) 

Cress, T. S., and Fenn, R. W. 

Climatology of Atmospheric Aerosols in Europe: 
Project OPAQUE 

SPIETech. Symp. East78, Wash., D. C. (28-31 March 
1978) 





204 


CUNNIFF, C. V. 

AFOL Infrared Survey Experiments Cleaning 
Procedure 

USAF/NASA Inti. Spacecraft Contamination Conf., 
USAF Acad., Colo. Springs, Colo. (7-9 March 1978) 

Del Greco, F. P., Kennealy, J. P., 
Robert, F. X., and Caledonia, G. E. (Phys. 

Sci., Inc., Woburn, Mass.) 

Nitric Oxide Vibrational Partitioning in the Reaction 
of Metaslable Atom ic Nitrogen ivith Molecular Oxygen 
Am. Chem. Soc. Natl. Mtg., New Orleans, La. (21-25 
March 1977) 

FENN, R. W. 

OPAQUE, A Measurement Program on Optical 
Atmospheric Quantities in Europe 
MORS Wkg. Gp., 42nd MORS Mtg., Naval War Coll., 
Newport, R. I. (6 December 1978) 

FENN, R. W., and SHETTLE, E. P. 

Models of the Optical Properties of Atmospheric 
Natural Background Aerosols 
TTCP Sub-Gp. J Mtg., Royal Signal Res. 
Establishment, Great Malvern, U K. (22-24 May 1978) 

Gibson, F., and Poirier, N. C. 

Measurement of Optical Scattering from Atmospheric 
Aerosols as a Function of Altitude 
10th AFGL Sci. Balloon Symp., The Wentworth-By- 
The-Sea, Portsmouth, N. H. (21-22 August 1978) 

Green, B. D., Caledonia, G. E. (Phys. sd., 
Inc., Woburn, Mass.)KENNEALY, J. P., and DEL 

Greco, F. P. 

Vibrationally Excited Nitric Oxide Produced in the 
Reaction Between Metastable Nitrogen Atoms and 
Oxygen Molecules 

Opt. Soc. of Am. Topical Conf. on Atm. Spectres., 
Keystone, Colo. (29 August - 1 September 1978) 

Kennealy, J. P„ Del Greco, F. P., 
Robert, F. X., Corman, A., and Moore, 

W. M. (Utah State Univ.) 

COCHISE: A Major Experimental Advance in the 
Study of Vibrational State Excitation by Infrared 
Emission Spectroscopy 

Am. Chem. Soc. Natl. Mtg., New Orleans, La. (21-26 
March 1977) 

Kennealy, J. P., and Del Greco, F. P. 

A Model and Evaluation of Atmospheric Nitric Oxide 
IR Radiation as an Essential Energy Transport 
Process 

Opt. Soc. of Am. Topical Conf. on Atm. Spectres., 
Keystone, Colo. (29 August -1 September 1978) 

Kennealy, J.P., and Moore, W.M., (Utah 

State Univ.) 

A Numerical Method for Chemical Kinetics Modeling 
Based on the Taylor Series Expansion 
Am. Chem. Soc. Natl. Mtg., New Orleans, La. (21-25 
March 1977) 


KNEIZYS, F. X., and SELBY, J. E. A. 
(Grumman Aerosp. Corp., Bethpage, N. Y.) 
LOWTRAN i Atmospheric Radiance Model 
26th Natl. IR Inf. Symp., AF Acad., Colo. (9-11 May 
1978) 


Kneizys, F. X. 

Atmospheric Transmittance and Radiance: The 
LOWTRAN Code 

Soc. of Photo-Opt. Instmn. Engrs. Tech. Symp., 
Wash., D. C. (28-31 March 1978) 

Me Clatchey, R. A. 

Transmittance Functions for Remote Sensing 
Symp. on Radn. in the Atm., Garmisch-Partenkirchen, 
Ger. (18-28 August 1976) 

New Developments in Laser Transmission Codes 
Mil. Ops. Res. Soc., U. S. Naval Postgrad. Sch., 
Monterey, Calif. (13-14 December 1977) 

How Far Can You See in the Infrared I 
(Invited Paper), Opt. Soc. of Am. Topical Conf. on 
Atm. Spectres., Keystone, Colo. (29 August -1 
September 1978) 

Atmospheric Propagation Modelling and 
Measurement 

DOD Tech. Exchange Conf., AF Acad., Colo. (28 
November - 1 December 1978) 

Me Clatchey, R. A., and Shettle, E. P. 

Atmospheric Optical Transmission Modelling and 
Prediction Schemes 

NATO/AGARD EPPSymp. on Op. Modeling of 
Aerosp. Prop. Envmt., Ottawa, Canada(24-28 April 
1978) 

Me Intyre, A. 

MSMP Results and Status 

Soc. of Photo Instmn. Engrs. Mtg., San Diego, Calif. 

(31 August 1978) 

Murdock, T. L., and Price, S. D. 

Infrared Emission from the Interplanetary Dust 
Cioud 

152nd Mtg. of Am. Astronom. Soc., Madison, Wis. 
(24-28 June 1978) 


Murphy, R. E. 

The BAMM System and Capabilities 

Def. Adv. Res. Projects Agcy., Strat. Sci. Symp., 

Menlo Pk„ Calif. (14-16 March 1978) 

Murphy, R. E., Rogers, J. W., Cook, F. 
H., and Caledonia, G. E. (Phys. sd„ inc., 

Woburn, Mass.) 

Fourier Spectroscopic Measurements of Transient CO 
Emissions 

Opt. Soc. of Am. Mtg., Tucson, Ariz. (18-22 October 
1976) 



206 


Nadile, R. M., Stair, A. T„ Wheeler, 
N. B., and FRODSHAM, D. J. GRIEDER, W. 
F. (Utah State Univ.) 

SPIRE — Spectral Infrared Rocket Experiment 
(Preliminary Reunite), II April 1978 
Def. Adv, Res. Projects Agcy. Strat. Sci. Symp., 
Menlo Pk., Calif. (14-16 Marc); 1978) 

Nadile, R. M., Wheeler, N. B., and 
Stair, A. T.,Jr. 

Spire-Spectral Infrared Experiment 

SPIE Soc. of Photo-Opt. Instmn. Engrs., San Diego, 

Calif. (23-26 August 1977) 

O’NEIL, R. R., and LEE, E. T. P. 

EXCEDE Experiment: Ground Baaed 
Telephotometer Measurements pfNt* in J91iA a>ul 
OCS) 5577A Eminsions 

Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 
(30 May-3 June 1977) 

Price, S. D. 

Calibration of the AFGL Survey Instruments 

L. A. Tech. Symp. (SPIE), Los Angeles, Calif. (16-18 

January 1978) 

Price, S. D., and Marcotte, L. P. 

Infrared Observations of the Zodiacal Dust Cloud 
152 nd Mtg. of Am. Astronom. Soc., Madison, Wis. 
(24-28 June 1978) 

Rothman, L. S. 

High Resolution Atmospheric Transmittance and 
Radiance: HITRAN and the Data Compilation 
Soc. of Photo-Opt. Instmn. Engrs. Tech. Symp., 
Wash., D. C. (28-31 March 1978) 

Status of the AFGL Atmospheric Absorption Line 
Parameters Compilation 

Atm. Opt. Tech. Gp., Opt. Soc. of Am., Tucson, Ariz. 
(October 1976) 

Rogers,J. W Stair, A. T.,Jr., 
Wheeler, N. B., and Wyatt, C. L., 

BAKER, D. J. (Electrodyn. Labs., Utah State 
Univ.) 

Rocketbome Measurements of Atmospheric 
Emissions from 7 toil, Micrometers 
Am. Geophys. Union 1977Spring Mtg., Wash., D. C. 
(30 May-3 June 1977) 

Sakai, H. 

Study of the i. 7 Micron COi Band at 625° K 
Mol. Spectros. Symp., Ohio State Univ., Columbus, 
Ohio (13-17 June 1977) 

High Resolution Fourier Spectroscopy at AFGL 
1977 Inti. Conf. on Fourier Transform IR Spectros., 
Univ. of So. Carolina, Columbia, S. C. (20-24 June 
1977) 

Sakai, H., and Murphy, R. E. 

Time-Resolved Fourier Spectroscopy 
(Invited Paper) 1977 Inti. Conf. on Fourier Transform 
IR Spectros., Univ. ofSo. Carolina, Columbia, S. C. 
(20-24 June 1977) 


SHETTLE, E. P. 

Atmospheric Aerosol Estimates for Atmospheric 
Optical Models 

Wkshp. on Remote Sensing of the Marine Boundary 
Layer, Vail, Colo. (9-11) August 1976) 

Radiative Transfer in Rural, Urban and Maritime 
Model Atmospheres 

Topical Mtg. on Atm. Aerosols: Their Opt. Properties 
and Eff., Williamsburg, Va. (13-16December 1976) 
Effects of Humidity Variations on Atmospheric 
Aerosol Optical Properties 
3rd Conf. on Atm. Radn., 

Univ. of Calif., Davis, Calif. (28-30June 1978) 

SHETTLE, E. P., and VOLZ, F. E. 

Optical Constants for a Meteoric Dust Aerosol Model 
Topical Mtg. on Atm. Aerosols: Their Opt. Properties 
and Eff., Williamsburg, Va. (13-16Dec 1976) 

Silverman, S. M. 

Auroral Frequency and Solar Activity 

Solar Terres. Coupling Conf., Yosemite, Calif. (8 

February 1978) 

Stair, A. T., Nadile, R. M., and 
Frodsham. D. G., Baker, D.J., and 
GRIEDER, W. F. (Utah State Univ.) 

Atmospheric Emission Spectra ( 148-16 pm) of the 
Earth's Limb (SPIRE) 

Topical Mtg. on Atm. Spectros, Opt. Soc. of Am., 
Keystone, Colo. (29 August -1 September 1978) 

Turner, V., Fenn, R., and Shettle, E. 

Atmospheric IR Transmittance and Scattering 
Properties in Europe 

8th DOD Conf. on Laser Technol., Naval Training 
Ctr., San Diego, Calif. (14-16 November 1978) 

VANASSE, G. A., EsPLIN, R., and HUPPI, R. 
(Stewart Rad. Lab., Bedford, Mass.) 

The SIMS Technique Applied to Background 
Suppression 

22nd Inti. Tech. SPIE Symp., San Diego, Calif. (28-31 
August 1978) 

VANASSE, G., and HUPPI, E. R. (Utah State 

Univ.) 

Enhanced Measurement Capability Using a 
Background Suppression Scheme 
1978 Jt. AF/Navy Sci. and Engrg. Symp., San Diego, 
Calif. (16-19 October 1978) 


VANASSE, G. A., and ZEHNPFENNIG, T. 

(Visidyne, Inc., Burlington, Mass.) 

Background Suppresion in Double-Beam 
Interferometry Using Tailored Modulation Transfer 
Functions 

22nd Inti. Tech. SPIE Symp., San Diego, Calif. (28-31 
August 1978) 





206 


Volz, F. E. 

The Nature of Atmospheric Aerosols from IR 
Spectroscopy 

Atm. Sci. Sem., Harvard Univ., Cambridge, Maas. (21 
April 1978) 

Infrared Characterization of Some Worldwide Aerosol 
Fractions 

Observations and Measurements of the Solar Aureole 
3rd Conf. on Atm. Radn., Univ. of Calif., Davis, Calif. 
(28-30 June 1978) 


TECHNICAL REPORTS 
JULY 1976 - DECEMBER 1978 


Baker, K. D., Baker, D. J. (Utah state 
Univ.), ULWICK, J. C., and STAIR, A. T., JR. 
Rocketbome Measurement of an Infrared 
Enhancement Associated with a Bright Auroral 
Breakup 

AFGL-TR-77-0157 (5 July 1977) 


Billingsley, F. P. 

Theory a nd Implementation of Velocity Compensation 
on the BAMM Sensor Platform 
AFGL-TR-77-0175 (3 August 1977) 

Caledonia, G. E., Green, B. D., Simons, 

G. A. (Phys. Sci., Ine.^Wobum, Mass.) 

Kennealy, J. P Robert, F. X„ 
CORMAN, A., and DEL GRECO, F. P. 
COCHISE Studies I: Fluid Dynamical and Infrared 
Spectral Analyses 

AFGL-TR-7741281 (9 December 1977) 


Clough, S. A., Kneizys, F. X., and 
Chetwynd, J. H., Jr. 

Algorithm for the Calculation of Absorption 
Coefficient-Pressure Broadened Molecular 
Transitions 

AFGL-TR-77-0164 (22 July 1977) 

CRESS, T. S., MaJ., and FENN, R. W„ Eds. 
OPAQUE Aerosol Counter Intercomparison, 25 
April -i May 1977 
AFGL-TR-78-0004 (9 January 1978) 

Climatology of Atmospheric Aerosols in Europe: 
Project OPAQUE 
AFLG-TR-78-0215 (March 1978) 


ESPLIN, R. W. (Electro-Dyn. Labs., Utah State 
Univ.), VANASSE, G. A., BAKER, D. J. (Utah 
State Univ.), and HUPPI, R. J. 

Increasing the Throughput of Hadamard 
Spectrometers by the Use of Curved Slots 
AFGL-TR-78-0232 (22 September 1978) 

Fenn, R. W. 

OPAQUE — A Measurement Program on Optical 
Atmospheric Quantities in Europe. Volume I — The 
NATO OPAQUE Program 
AFGL-TR-78-0011 (17 January 1978) 


Green, B. D., Caledonia, G. E. (Phys. Sci., 
Inc., Woburn, Mass.), and MURPHY, R. E. 
SWIR-MWIR Electron Fluorescence Measurements 
in NtlOt and Air 
AFGL-TR-78-0083 (4 April 1978) 

McClatchey, R. A. 

Satellite Temperature Sound)ng of the Atmosphere: 
Ground Truth Analysis 
AFGL-TR-76-0279 (19 November 1976) 

McClatchey, R. A., and D’Agati, A. P. 

Atmospheric Transmission of Laser Radiation: 

Computer Code LASER 

AFG L-TR-78-0029 (31 January 1978) 

Moore, W. M. 

Design a nd Fa brication of a Prototype Cold 
Background Experimental Reaction Chamber and 
Spectral Detection System 
AFGL-TR-77-0306 (December 1977) 

Murdock, T. L. 

Separation of Earth Limb Radiation from Infrared 
Zodiacal Light 

AFGL-TR-78-0040 (October 1977) 

Infrared Emission from the Interplanetary Dust 
Cioud at Small Sola> Elongation Angles 
AFGL-TR-77-0280 (Dt<-ember 1977) 

Murphy, R. E, Cook, F. H., Caledonia, 
G. E, and GREEN, B. D. (Phys. Sci., Inc., 
Woburn, Mass.) 

Infrared Fluorescence of Electron Irradiated COi in 
the Presence of Nt, Ar, and He 
AFGL-TR-77^0205 (15 September 1977) 

Nadile, R. M., Stair, A. T., Jr., 
Wheeler, N. B., Frodsham, D. G., 
Wyatt, C. L., Baker, D. J., andGRiEDER, 
W. F. (Utah State Univ.) 

SPIRE — Spectral Infrared Rocket Experiment 
(Preliminary Results) 

AFGL-TR-78-0107 (11 April 1978) 

O’Neil, R.R., Ed. 

PRECEDE II: Summarized Results of an Artificial 
Auroral Experiment 
AFGL-TR-78-0063 (16 March 1978) 

O’Neil, R.R., Lee, E. T. P., Stair, A. T., 
JR., and ULWICK, J. C. 

EXCEDEII 

AFGL-TR-76-0308 (21 December 1976) 

Pelzmann, R. F., Jr., 

Final Report: SUPER HI-STAR Experiment 
AFGL-TR-78-0047 (21 February 1978) 

Price, S. D. 

The AFGL Four Color Infrared Sky Survey: 
Supplemental Catalog 
AFGL-TR-77-0160(12July 1977) 





• r rr m* p. 


207 


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Price, S. D., Akerstrom, D. S.. 
Cunniff, C. V., Marcotte, L. P., Tandy, 
P. C., and WALKER, R. G. (NASA Ames Res. 
Ctr., Moffett Fid., Calif.) 

Aspect Determination for the AFGL Infrared Survey 
Experiments 

AFGL-TR-78-0253 U6 October 1978) 

Price, S. D., Cunniff, C. V.,and 

WALKER, R. G. (NASA Ames Res. Ctr., Moffett 
Fid., Calif.) 

Cleanliness Considerations for the AFGL Infrared 
Celestial Survey 
AFGL-TR-78-0171 (6 July 1978) 

Price, S. D., and Walker, R. G. 

The AFGL Four Color Infrared Sky Survey: Catalog 
of Observations at i.2, 11.0, 19.8 and 274 pm 
AFGL-TR-76-0208 G7 September 1976) 

Calibration of the HI STAR Sensors 
AFGL-TR-78-0172 (3 July 1978) 

Rahbee, A., Gibson, J. J., and Dolan, C. 

Vibrational Excitation of Carbon Dioxide and Carbon 
Monoxide by High Velocity Collision with Molecular 
Oxygen 

AFGL-TR-77-0025 (26 January 1977) 

Rogers, J. W.. Stair, A. T., Jr., 
Wheeler, N. B., and Wyatt, C. L. 

BAKER, D. J. (Electro-Dyn. Labs., Utah State 
Univ.) 

LWIR (7-2i pm) Measurements from the Launch of a 
Rocketbome Spectrometer into an Aurora (1973) 
AFGL-TR-76-0274 (15 November 1976) 

LWIR <7-21, pm) Measurements from the Launch of a 
Rocketbome Spectrometer into a Quiet Atmosphere 
(197!,) 

AFGL-TR-77-0113 (24 May 1977) 

Sakai, H. 

High-Resolution Spectra ofCH • in the 2700 to 3200 
cm ' Region 

AFGL-TR-76-0280 (29 November 1976) 

Sakai, H. and Vanasse, G. A. 

High Resolution Spectra ofCOt in the 3500 to 3770 
cm 1 Region at 625° K 
AFGL-TR-77-0039 (10 February 1977) 

Selby, J. E. A., Kneizys, F. X., 
Chetwynd, J. H., Jr., and McClatchey, 
R. A. 

Atmospheric Transmittance!Radiance: Computer 
Code LOWTRAN k 
AFGL-TR-78-0053 (28 February 1978) 

Selby, J. E. A.. Shettle, E. P., and 
McClatchey, R. A. 

Atmospheric Transmittance from 0.25 to 28.5 pm: 
Supplement LOWTRAN SB <1976) 

AFGL-TR-76-0258 (1 November 1976) 


Shettle, E. P. 

Effects of Humidity Variations on Atmospheric 
Aerosol Optical Properties 
AFGL-TR-78-0197 (June 1978) 

Smith, H. J. P., Dube, D. J. (Visidyne, 

Burlington, Mass.), GARDNER, M. E., CLOUGH, 

S. A., Kneizys, F. X., and Rothman, L. S. 

FASCODE — Fast Atmospheric Signature Code 
(Spectral Transmittance and Radiance) 
AFGL-TR-78-0081 (1978) 

Valovcin, F. R. 

Spectral Radiance of Snow and Clouds in the Near 
Infrared Spectral Region 
AFGL-TR-78-0289 (17 November 1978) 

Snow/Cloud Discrimination 
AFGL-TR-76-0174 (4 August 1976) 

Meteorological Satellite Measurements 
AFGL-TR-77-0035 (3 February 1977) 

Vanasse, G. A., and Sakai, H. 

Study of the Dual-Input Mode with the AFGL Two- 
Meter Path Difference Interferometer 
AFGL-TR-77-0213 (4 October 1977) 


Vanasse, G. A., Esplin, R. W., and 

HUPPI, R. J. (Stewart Radiance Lab., Utah State 
Univ.) 

The SIMS Tech n ique Applied to Backgrou nd 
Suppression 

AFGL-TR-78-0222 (18 September 1978) 


Vanasse, G. A., Stair, A. T., Jr., 

SHEPHERD, 0., and ReIDY, W. (Visidyne, Inc., 
Burlington, Mass.) 

Background Optical Suppression Scheme (BOSS) 
AFGL-TR-77-0135 (17 June 1977) 

Volz, F. E. 

Atmospheric Turbidity in Europe, 1963-1969 
AFGL-TR-78-0108 (21 April 1978) 

Wheeler, N. B., Stair, A. T., Jr., 
FRODSHAM, G. , and BAKER, D. J. (Utah State 
Univ.) 

Rocket-Borne Spectral Measurement of Atmospheric 
Infrared Emission During a Quiet Condition in the 
Auroral Zone 

AFGL-TR-76-0252 (27 October 1976) 


ZEHNPFENNIG, T. F. (Visidyne, Inc.. 
Burlington, Mass.), and VANASSE, G. A. 
Background Suppression in Double-Beam 
Interferometry Using Tailored Modulation Transfer 
Functions 

AFGL-TR-78-0221 (18 September 1978) 





208 


CONTRACTOR JOURNAL ARTICLES 
JULY 1976 - DECEMBER 1978 

Baker, K. D., Baker, D. J. (Utah state 
Univ.), ULWICK, J. C., and STAIR, A. T., JR. 
Measurements of 1.5- to 5.3- pm Infrared 
Enchancements Associated with a Bright Auroral 
Breakup 

J. of Geophys. Res., Vol. 82, No. 25 (1 September 1977) 

W HITNEY, C. (The Charles Stark Draper Lab., 
Inc., Cambridge, Mass.) 

Extendi ng Radiative Tra nsfer Models bg l ’seof Bayes' 
Rule 

J. of Atm. Sei., Vol. 34, No. 5 (May 1977) 

Wyatt, C. L., and Frodsham, D. G. 

(Electro-Dyn. Lab., Utah State Univ.) 

Short Wavelength Rocket borne Infrared Spectrometer 
Proc. ofSoc. ofPhoto-Opt. Instmn. Engrs., Vol. 124 
(25-26 August 1977) 

CONTRACTOR TECHNICAL 
REPORTS 

JULY 1976 - DECEMBER 1978 


BAKER, D. J. (Eleetro-Dyn. Labs., Utah State 
Univ.) 

Studies of Atmospheric hlfmred Emissions 
Ah GL-T R-78-0251 (December 1977) 

Baker, K. D., Eaker, D. J., Howlett, L. 
C., and JENSEN, L. L. (Space Sci. Lab., Utah 
State Univ.) 

Studies of the Disturbed Vpper Atmosphere Utilizing 
Rocket borne Instrumentation 
AFGL-TR-77-0223 (October 1977) 

BARAKAT, R., (Bolt, Beranekand Newman, Inc., 
Cambridge, Mass.) 

A« Approach to the Analysis of Vibrational- 
Rotational Interactions in Molecules 
AFGL-TR-76-0277 (September 1976) 

BlEN, F. (Aerodyne Res., Inc., Bedford, Mass.) 
Analysis of Electron Retarding Potential Analyzer 
Measurements of Vehicle Skin Potential in the 
PRECEDE Experiment 
AFGL-TR-78-0050 (January 1978) 

BRIOTTA D. A., Jr., PlPHER, J. L. and 
Houck, J. R. (Cornell Univ., Ctr. for Radiophys. 
and Space Res., Ithaca, N. Y.) 

Rocket Infrared Spectroscopy of the Zodiacal Dust 
Cloud 

AFGL-TR-76-0236 (1 Oi tober 1976) 

Davies, R. W., and OLI, B. A. (Univ. ofLowell, 
Ctr. for Atm. Res., Lowe'l, Mass.) 

Theoretical Calculations ofHtO Linewidths and 
Pressure Shifts: Compa ris< mo/Anderson Theory with 
Quantum Many-Body Theory for Nt and Air 
Broadened Lines 

AFGL-TR-78-0001 (December 1977) 


DEGGES, T. C., and SMITH, II. J. P, (Visidyn. 
Inc,, Burlington, Mass.) 

A High Altitude Infrared Radiance Model 
AFGL-TR-77-0271 (November 1977) 

Duntley, S. Q- , Johnson, R. W., and 

GORDON, J. L. (Visibility Lab., Univ. of Calif, at 
San Diego) 

Airborne Measurements of Optical Atmospheric 
Properties, Summary and Review III 
AFGL-TR-78-0286 (December 1978) 

Airborne Measurements of Optical Atmospheric 
Properties in Northern Germany 
AFGL-TR-76-0188 (September 1976) 

Airborne Measurements of Atmospheric Volume 
Scattering Coefficients in Northern Europe. Fall 1976 
AFGL-TR-77-0239 (January 1978) 

Airborne Measurements of Atmospheric Volume 
Scattering Coefficients in Northern Europe, Spring 

1976 

AFGL-TR-77-0078 (March 1977) 

Airborne Measurements of Atmospheric Volume 
Scattering Coefficients in Northern Europe, Summer 

1977 

AFGL-TR-78-0168 (June 1978) 

Dyke, T. R., Mack, K. M., and Muenter, 

J. S. (Univ. of Rochester, N. Y.) 

The Structure of Water Dimer from Molecular Beam 
Electric Resonance Spectroscopy 
AFGL-TR-76-0216 (1 September 1976) 

Eng, R. S., and MANTZ, A. W. (Laser 
Analytics, Inc., Lexington, Mass.) 

Tunable Diode Laser Measurements ofHtOand COt 
Line Parameters in the 10-15 pm Spectral Region 
AFGL-TR-78-0178 (June 1978) 


Green, B. D., Wilemski, G., and 
Caledonia, G. E. (Phys. sci., inc., Wobum, 
Mass.) 

Remote Infrared Monitoring of Selected Tritiated 
Molecides 

AFGL-TR-78-0114 (December 1977) 

Hansen, P., Sakai, H., and Strong, J. 

(Astron. Res. Facility, Univ. of Mass.) 

/ n fra red E m ission Spectroscopy of Low Pressure 
Gaseous Discharges 
AFGL-TR-77-0251 (1 November 1977) 

Grieder, W. F., Messuri, D. J., 
Whelan, T. P., and Bucknam, R. D. 

(Visidyne, Inc. Burlington, Mass.) 

Design and Test of a Mobile Mission Control Station 
for Use in Balloon-Borne Infrared Research 
Experiments (B AMM Project) 

AFGL-TR-78-0104 (10 April 1978) 



209 


GRYVNAK, D. A., and Burch, D. E, (Ford 
Aerosp. and Comm. Co;p., Newport Beach, Calif.) 
Infra red Absorption by COt and HtO 
AFGL-TR-78-0154 (May 1978) 

Gryvnak, A., Burch, D. E., and Alt, R. 

L. (Ford Aerosp. and Comm. Corp., Newport Beach, 
Calif.) 

Infrared Absorption by Chi, HtO and COt 
AFGL-TR-76-0246 (December 1976) 

Hansen, P.. Lauzzana, R., Sakai, H., and 

STRONG, J. (Astron. Res. Facility, Univ. of Mass.) 
Theoretical Study of Background Radiance in Upper 
Atmosphere 

AFGL-TR-78-0013 (December 1977) 

HEGBLOM, E. R. (Boston Coll., Chestnut Hill, 
Mass.) 

Analysis of Auroral Electron Data 
AFGL-TR-78-0127 (1 May 1978) 

HOWLETT, L. C., and BAKER, K. D. (Utah 
State Univ.) 

Development of a Rocket-Borne Resona nee Lamp 
System for the Measurement of Atomic Oxygen 
AFGL-TR-77-0227 (August 1977) 

HUPPI, R. J. (Utah State Univ.) 

Radiometric Instrumentation and Techniques for 
Measuring Infrared Emissions from the Atmosphere 
and Targets 

AFGL-TR-76-0253 <29 October 1976) 

HUPPI, R. J., and Reed, J. W. (Utah State 
Univ.) 

Aircraft-Borne Measurements of Nitric Oxide 
Enhancements [hiring ICECAP 1975 and 1976 
AFGL-TR-77-0232 (September' 1977) 

HUPPI, R. J., and SCHUMMERS, J. H. (Utah 
State Univ.) 

Aircraft-Borne Infrared Measurements 
AFGL-TR-78-0039 (1 January 1978) 

Hurd, A. G., Degges, T. C., Reidy, W. 
P., Shepherd, 0., andGRiEDER, W. F. 
(Viaidyne, Inc,, Burlington, Mass.) 

Comparison of ICECAP and EXCEDE Rocket 
Measurements with Computer Code Predictions 
AFGL-TR-77-0060 (15 February 1977) 

KRYGER, D., and ROBERTSON, D. (Aerodyne 
Res., Inc., Bedford, Mass.) 

Medium Resolution Data Analysis 
AFGL-TR-77-0044 (January 1977) 

LlN, C. C. and CHUNG, S. (Univ. of Wisconsin) 
Molecular Reaction Rates 
AFGL-TR-78-0262 (30 October 1978) 

McCue, R. A., Harris. R. D., Baker, K. 
D. , and WESTLUND, C. D. (Utah State Univ.) 
Analysis of the Faraday Rotation Differential 
Absorption Technique for D-Region Measurements 
AFGL-TR-77-0184 (August 1977) 


MlGEOTTE, M. V. (Inst, of Astrophys., Univ. of 
Liege, Belgium) 

High Resolution Transmission Measurements of the 
Atmosphere in the Infrared (Sci. Rpt. No. 1) 
AFGL-TR-77-0172 (31 May 1977) 

High Resolution Transmission Measurements of the 
Atmosphere in the Infrared (Sci. Rpt. No. 2) 
AFGL-TR-78-0165 (28 April 1978) 

Miranda, H. A., Jr., and Dulchinos, J. 

(Epsilon Labs., Bedford, Mass.) 

Improvements and Modifications to the Epsilon / 
AFGL Balloon-Borne Sub-Micron Particle Counter 
AFGL-TR-76-0211 (September 1976) 

Moore, W. M. (Utah Stale Univ.) 

Design and Fabrication of a Prototype Cold 
Background Experimental Reaction Chamber and 
Spectral Detection System 
AFGL-TR-77-0306 (31 December 1977) 

Mount, W. D., Fow, B. R., Gustafson, 

D. E., and LeDSHAM, W. (Geo-Atm. Corp., 
Lincoln, Mass.) 

Error Analyses of Operational Satellite Soundings of 
Vertical Temperature Profiles 
AFGL-TR-77-0248(31 December 1977) 

Murcray, D. G., Murcray, F. H., 
MuRCRAY, F. J., and WILLIAMS, W. J. (Univ. 
of Denver) 

InfraredF -.ckgroundMeasurements 
AFGL-TR-78-0249 (September 1978) 

POWERS, J. E., and DIRKMAN, R. J. (Univ. of 
Lowell, Mass.) 

The Development and Support of the NATO Project 
OPAQUE USAF System Control Programs 
AFGL-TR-78-0176 (July 1978) 

PRITCHARD, J. L. (Idealab, Inc., Franklin, Mass.) 
Cryogenic Airborne Interferometer 
AFGL-TR-76-0311 (December 1976) 

Cryogenic Enclosure for a Coolable Interferometer 
AFGL-TR-77-0226 (15 October 1977) 

ROBERTSON, D., and SPECHT, R. (Aerodyne 
Res., Inc., Bedford, Mass.) 

A User's Guide to MIDTRAN — A Combination of 
LOWTRAN and HITRAN Technologies 
AFGL-TR-78-0184 (June 1978) 

ROMICK, G. J. (Geophys. Inst., Univ. of Alaska) 
Report on the Geophysical Description and Available 
Data Associated with Rocket PF-SGT-116 
AFGL-TR-77-0073 (March 1977) 

Shepherd, 0., Zehnpfennig, T. F., 

REIDY, W. P., (Visidyne, Inc., Burlington, Mass.), 
VANASSE, G. A., and STAIR, A. T., JR. 

IR Background Suppression Studies 
AFGL-TR-77-0277 (May 1977) 



210 


Shuler, M. P., Jr., and Stewart, H. S. 

(HSS. Inc., Bedford, Mass.) 

Remote Sensing of Atmospheric Visibility: A Critical 
Review 

AFGL-TR-78-0216 <30 April 1978) 

Sluder, R. B. (PhotoMet., Ine., Lexington, 
Mass.) 

Photographic Measurements of Electrical Discharges 
AFGL-TR-78-0006 (15 November 1977) 

SLUDER, R. B., and KOFSKY, I. L. (PhotoMet., 
Inc., Lexington, Mass.) 

Aircraft Program for Target and Background 
Measurements 

AFGL-TR-77-0048 (18 February 1977) 

Sluder, R. B., Villanucci,D. P., 
Andrus, W. S., and Kofsky, I. L. 

(PhotoMet., Inc., Lexington, Mass.) 

Aircraft Program for Target, Background, and Sky 
Radiance Measurements 
AFGL-TR-78-0123 (18 May 1978) 

Smith, H. J. P. , Dube, D. J. , Gardner, M. 

E. (Visidyne, Inc., Burlington, Mass.). CLOUGH , 
S. A., KNEIZYS, F. X., and ROTHMAN, L. S. 
FASCODE —- Fast Atmospheric Signature Code 
(Spectral Transmittance and Radiance) 
AFGL-TR-78-0081 (16 January 1978) 

Smith, H. J. P., Gardner, M. E ., and 
CARPENTER, J. W. (Visidyne, Inc., Burlington, 

Mass.) 

The TACTIR Code 
AFGL-TR-77-0291 (February 1976) 

SMITH, M. A. (Utah Suite Univ.) 

Design and Development of a Telemetry Logging 
System 

AFGL-TR-78-0180 (June 1978) 


Staelin, D. H., Rosenkranz, P. W., 
Cassel, A., McDonough, D., and 

STEFFES, P. (Mass. Inst, of Technol.) 
Atmospheric Measurements Near 1 IS GHz with 
Passive Microwave Techniques 
AFGL-TR-78-0183 (June 1978) 

SHOU-CHI Sue, and Baker, D. J. (Utah State 

Univ.) 

Computer-Aided Estimates of the Rotational 
Temperatures of Ot in the Mesosphere 
AFGL-TR-76-0212(July 1976) 

Whitney, C. K., and Malchow, H. L. (The 

Charles Stark Draper Lab., Cambridge, Mass.) 

Study of Radiative Transfer in Scattering 
Atmospheres 

AFGL-TR-78-0101 (June 1977) 

WILLIAMSON, W. R. (Honeywell Radn. Ctr., 
Lexington, Maas.) 

High-Rejection Telescopes, Utah State University 
Telescopes HS-i, S’S-J, AND TPM-t 
AFGL-TR-77-0099 (31 January 1977) 

ZACHOR, A. S. (Honeywell Electro-Opt. Ctr., 
Lexington, Mass.) 

Study of TempendurelMoisture Retrieval Capabilities 
of DMSPISSH Sensor Cha nnels 
AFGL-TR-78-0279 (September 1978) 

Zehnpfennig, T. F., Rappaport, S., 

REIDY, W. P., and SHEPHERD, 0. (Visidyne, 
Inc., Burlington, Mass.) 

Tailored Modulation Transfer Function and the 
Application to Dual Beam Interferometry 
AFGL-TR-78-0077 (March 1978) 



211 


Appendix A 


AFGL PROJECTS BY PROGRAM ELEMENT 


Program Project Number, Title, and Agancy 

6110IF ILIR Laboratory Director’s Fund 

61102F DEFENSE RESEARCH SCIENCES 

2303G1 Upper Atmosphere Chemistry 

2303G2 Plume-Atmosphere Interactions 

2309G1 Earth Sciences and Technologies 

2309G2 Crustal Motion Studies 

2310G1 I nfrared and Optical Techniques 

2310G2 Atmospheric Dynamics 

2310G3 Upper Atmosphere Composition 

2310G4 Infrared Non-Equilibrium 

Radiation Mechanisms 
2310G5 Cloud Physics 

2311G1 Energetic Particles and Magnetic Fields 

2311G2 Electrical Structure of Aerospace 

2311G3 Solar Environmental Disturbances 

62101F GEOPHYSICS 

4642 Aerospace Radio Propagation 

6670 Meteorological Development 

6687 Stratospheric Environment 

6690 Upper Atmosphere Technology 

7600 Terrestrial Sciences 

7601 Magnetospheric Effects on Space Systems 

7659 Aerospace Probe Technology 

7661 Spacecraft Charging Technology 

7670 Optical/IR Properties of the Environment 





r 


212 


In addition to the above continuing Air Force funded projects, 
AFGL participates in joint programs supported by the following 
agencies: 

1) U. S. Air Force: 

Air Force Avionics Laboratory 

Air Force Technical Applications Center 

Air Force Weapons Laboratory 

Air Weather Service 

Electronic Systems Division 

Space and Missile Systems Organization 

Ogden Air Logistics Center 

2) Army 

3) Advanced Research Projects Agency 

4) Defense Mapping Agency 

5) Defense Nuclear Agency 

6) Department of Energy 

7) NASA 





AFGL ROCKET PROGRAM: JULY 1976 - DECEMBER 1978 


214 





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2s SS U5U, S2 SHgSSiS 2 88 882 




215 




APPENDIX C 


Air Force Geophysics Laboratory 

HANSCOM AIR FORCE RASE. BEDFORD. MAH. 



AS OF 17 JULY 1978 
•ACTING 





















216 


cc 

COMMANDER 

COL. 6 S. MORGAN. Jfl 

cv 

VICE COMMANDER 

COL C G.R. CZEPYHA 


XO TECHNICAL PLANS 6 OPERATIONS 



su 

RESEARCH SERVICES 



Director S J. Falkowtki 



Duaclor 

L_- 

J.D Murphy 


Af GL TECHNICAL CONSULTATION SERVICE 

Technical Consultation Services Officer 

R T Po0*edlo 
AFGL Staff Meteorologists 


Col. G W. King 

AFSC 

Lt. Col. R F Wachtmann 

SAMTEC 

Lt. Col. W E. Buchan 

AFETR 

Lt. Co( J Sartor 

ADTC 

Lt. Col C H Bush 

AFFTC 

Lt Col F, Fowler 

SAMSO 

Lt Col J Lasley 

ASD 

Maj. D A Morss 

FTD 

Capt. S Y. Strader 

6685 TG 

Capt 0 E. Bialick* 

AFRPL 

Maj 0 8 Johnson 

RADC 

Lt Col. E W Frey 

AFWL 

Mai P. Soliz 

AFAL 

Capt G. Jackson 

AFFOL 

Mai J B Hooten 

AFCEC 

Lt. Col C B Givans 

ESD 

Lt. Col H.J.E. Fischer 

i SCF 


XOP 

TECHNICAL PROGRAMS BRANCH 

Chief 

R.A. Skrwanek 


XOR 

Chief 

RESOURCES BRANCH 

J.l. Matey. Jr. 


AT 

Chief 

WEST COAST OFFICE 

El Segundo. California 

J Hess 


SUO OPERATIONAL SERVICES BRANCH 

Chief 

J.P. Cushman 

SUOCLMCA 

G Smkevich 

SUOF Technical Facilities 

W K Foss 

SUOR Field Requirements 

J.F Murphy 

SUOS R6D Fabrication 

R J Campbell 


SUD C’ATA PROCISSING BRANCH 


Chief 


SUDA Computer Operations 
1st Shift 
2nd Shift 
3rd Shift 

SUDC Systems Programming 


R G Gosselm 

0 J LaChanca 
R.R. DaPolito 
J R DeVito 
S- Smith 


SUL MANAGEMENT b ADMINISTRATIVE 

SERVICES BRANCH 


Chief 

t G CorliM 

DA Administrative Services SSgl R Plamondon 

SULL Research Library 

E L Cunha 

SULR Research Publications 

A . G Mueller 

SULM Management Services 

E G Corliu* 


SUA ANALYSIS & SIMULATION BRANCH 
Chut R.E. Mclnernay* 


SUH 

Chief 


DECOMMUTATION BRANCH 

R C. Penney 


SUP technical PHOTOGRAPHY BRANCH 
(Special mimon photographic laboratory) 

Chraf C. Rod bar g 


SUM MECHANICAL ENGINEERING BRANCH 
Chi«* S. Rosenthal 


AS OF 18 September 1978 

•ACTING 






















•m 



AS OF 17 JULY 1978 
• ACTING 


☆ U.S. GOVERNMENT PRINTING OFFICE: 1981 -A-2161/26