VLA observations at 20 and 90 cm of five distant Galactic H II regions in an area including the Sharpless S53 complex have been used to measure their effective sizes and optically thick continuum flux densities. These data have been combined with shorter wavelength, optically thin flux density measurements and electron temperature estimates to determine accurate emission measures where previous results gave only lower limits. Our analysis indicates that existing lower limits to the emission...
Topics: DTIC Archive, Kassim, Namir E, NAVAL RESEARCH LAB WASHINGTON DC E O HULBURT CENTER FOR SPACE...
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Jun 13, 2020
06/20
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Wohlleben, Rudolf, 1936-
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xiv, 210 p. : 25 cm
Topics: Radio interferometers, Radio astronomy, Interferometry
Electrical properties of frozen ground were measured using radio frequency interferometry (RFI) in the very high frequency (VHF) radiowave band. Ice-rich organic silts and sands and gravels of variable ice content were investigated during early April of both 1979 and 1980. Frequencies between 10 and 150 MHz were used with best results obtained between 40 and 100 MHz. Surface impedance and magnetic induction techniques were also used to obtain an independent measure of low frequency resistivity...
Topics: DTIC Archive, Arcone,Steven A, COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH, *PERMAFROST,...
The contractors conducted an experimental and analytical study of the mechanics of fasteners in FGRP composites. Areas of study considered in the contract included multiple-fastener arrays, load spreading washers of three types, bolt preload effects, field measurement, developement of analytical and experimental methods, parametric studies, and creation of design codes. A comprehensive study of literature pertaining to methods of mechanically fastening composites was undertaken, and a summary...
Topics: DTIC Archive, Cloud, Gary, MICHIGAN STATE UNIV EAST LANSING DEPT OF METALLURGY MECHANICS AND...
A high pressure liquid cell interferometer to measure the variation of refractive index of liquids with pressure to 14 kbars has been constructed. The amount of liquid needed is only 3 c.c. Interferometric measurements have been carried out on twelve liquids with widely varying molecular size, shape and structure. These studies show (1) first experimental proof that the Eulerian frame-indifferent analogue strain E is a more useful strain measure than the Lagrangian strain, (2) Keane's equation...
Topics: DTIC Archive, Limsuwan,Pichet, PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB,...
Carbon has been implanted into monocrystalline (100) copper substrates. Owing to the low solubility of C in Cu, it was easily diffused to a clean Cu surface at 550 C in the form of graphite rather than the desired diamond, as shown by Auger electron spectroscopy measurements. Laser reflection interferometry has proven to be a useful technique in the study of diamond growth processes. Nucleation and growth rates were monitored in real time. The problem of surface roughness of the polycrystalline...
Topics: DTIC Archive, Davis, Robert F, NORTH CAROLINA STATE UNIV AT RALEIGH, *MEASUREMENT, GROWTH(GENERAL),...
The Amaldi 10 Parallel Session C2 on gravitational wave(GW) search results, data analysis and parameter estimation included three lively sessions of lectures by 13 presenters, and 34 posters. The talks and posters covered a huge range of material, including results and analysis techniques for ground-based GW detectors, targeting anticipated signals from different astrophysical sources: compact binary inspiral, merger and ringdown; GW bursts from intermediate mass binary black hole mergers,...
Topics: NASA Technical Reports Server (NTRS), GRAVITATIONAL WAVES, LASER INTERFEROMETRY, WAVEFORMS,...
The Naval Space Surveillance Center (NAVSPASUR) is an operational naval command that has the mission of determining the location of all manmade objects in space and transmitting information on objects of interest to the fleet. NAVSPASUR operates a 217 MHz radar fence that has 9 transmitting and receiving stations deployed in a line across southern CONUS. This surveillance fence provides unalerted detection of all satellites overflying CONUS. NAVSPASUR also maintains a space catalog of all...
Topics: DTIC Archive, NAVAL SPACE SURVEILLANCE CENTER DAHLGREN VA, *COMMUNICATION EQUIPMENT, *COMMUNICATION...
Instrumentation for frequency modulation spectroscopy studies of hole burning materials for optical storage, and a phase sensitive interferometric correlator for photon echoes detection has been purchased. Applications of phase sensitive correlator to phase stability characterization and heterodyne detection of optical signals were demonstrated using the equipment.
Topics: DTIC Archive, Gorokhovsky, A., NEW YORK CITY COMMUNITY COLL BROOKLYN, *PHOTODISSOCIATION, *OPTICAL...
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Atiquzzaman, Mohammed; Ivancic, William, et al; Chitri, Jyotsna; Ahamed, Faruque; Su, Hongjun; Bai, Haowei; Jain, Raj; Goyal, Mukul; Chadavala, Bharani; Paul, Arindam
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This viewgraph information provides information on establishing Quality of Service (QoS) for satellite communication networks.
Topics: VERY LONG BASE INTERFEROMETRY, ANTENNAS, GEODESY, SITE SELECTION
Using the technique of heterodyne interferometry, measurements were made of the spatial distribution of 11 micron radiation from four late type stars. The circumstellar shells surrounding VY Canis Majoris, alpha Orionis, and alpha Scorpii were resolved, whereas that of R Leonis was only partially resolved at a fringe spacing of 0.4 sec.
Topics: NASA Technical Reports Server (NTRS), INTERFEROMETRY, LATE STARS, STELLAR ENVELOPES, STELLAR...
A range of very long baseline interferometry experiments applied to Earth physics are covered.
Topics: NASA Technical Reports Server (NTRS), GEODETIC SURVEYS, GEOPHYSICS, VERY LONG BASE INTERFEROMETRY,...
Our long-term scientific goal is to understand the basic physics of low-frequency sound propagation in the ocean, and the effects of environmental variability on signal stability and coherence. We seek to understand the fundamental limits to signal processing imposed by ocean variability to enable advanced signal processing techniques, including matched field processing and other adaptive array processing methods. Work on this project has focused on noise interferometry the process by which an...
Topics: DTIC Archive, Brown,Michael G, University of Miami Miami United States, signal processing, water...
An exploratory research program has been conducted to systematically evaluate the effects of biaxial stress ratio on constant amplitude and variable amplitude fatigue crack growth rates. A series of experiments and analyses have been carried out on the cyclic crack growth behavior of center-cracked cruciform specimens under various biaxial loading conditions.
Topics: DTIC Archive, Liu, A. F., NORTHROP CORP HAWTHORNE CA AIRCRAFT GROUP, *CRACK PROPAGATION, *BIAXIAL...
A new pressure sensing device has been analyzed, built, and tested. The device uses a Michelson interferometer to monitor pressure-induced fluctuations of a polished silicon diaphragm. Probe flexibility is achieved by mounting the diaphragm on the end of a single mode optical fiber; the coupling apparatus used permits interference to occur with the fiber in one leg of the interferometer. The phase of the resulting pattern is locked using a piezoelectric length transducer and phaselock loop...
Topics: DTIC Archive, Preston,Eddie J, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF...
Two methods are described for measuring interferometric fringe contrast with sensing arrays. The absence of air turbulence allows contrast to be determined quickly by measuring the intensity of the fringe pattern at phases 90 deg apart. The presence of turbulence requires that the peak-to-peak fringe intensity be found by sampling the fringes as they are scanned across the array. An analysis is presented showing the relation between maximum error in fringe contrast measurement and the number of...
Topics: DTIC Archive, Seemuller,William, ARMY ENGINEER TOPOGRAPHIC LABS FORT BELVOIR VA, *IMAGE PROCESSING,...
The descriptive model of scintillation-producing irregularities in the F layer contained in Program WBMOD has been improved, along with other aspects of the code. Improvements include use of magnetic local time for modeling high-latitude boundaries, correction of a subtle error in calculating the scan velocity of the radio line of sight, simplification of the orbit calculation, and implementation of an irregularity drift routine based on a recently published model of ionospheric convention at...
Topics: DTIC Archive, Secan, James A., PHYSICAL DYNAMICS INC BELLEVUE WA, *COMPUTER PROGRAMS,...
The solar microwave spectrum encodes significant information on plasma parameters, magnetic field strengths and characteristics of accelerated electrons in solar flares and active regions. The solar interferometer of the Owens Valley Radio Observatory has recently been converted to frequency-agile operation to effectively become a high resolution, interferometric spectrometer. The interferometer uses two moveable, 27 m diameter parabolic antennas equipped with frequency-agile receivers. These...
Topics: DTIC Archive, Hurford,G J, CALIFORNIA INST OF TECH PASADENA, *MICROWAVE INTERFEROMETRY, *FREQUENCY...
A summary of progress on the development of instrumentation to determine with great accuracy the in-plane and out-of-plane surface deformations in the vicinity of a crack tip. The purpose is to establish a data base for a) guiding theoretical research in characterizing the deformation fields in the crack tip vicinity for fracture research and b) to provide factual information for the evaluation of currently proposed theories dealing with crack tip deformation. The experimental tools under...
Topics: DTIC Archive, Schultheisz,C, CALIFORNIA INST OF TECH PASADENA GRADUATE AERONAUTICAL LABS,...
The feasibility of the GeoBeacon system is studied. In this system, low-power radio transmitters are placed on vehicles or at other points whose positions are to be monitored. Tropospheric and ionospheric refraction are also monitored. The number of transmitters is practically unlimited. Signals from all transmitters in view are repeated by satellites to a central site where detection, measurement, and data processing take place. To enable precise geodetic positioning, signals would be emitted...
Topics: DTIC Archive, Cangahuala, Laureano A, MASSACHUSETTS INST OF TECH CAMBRIDGE, *TRACKING, *RADIO...
This program is investigating matter wave interferometry with laser cooled atoms. A slow beam of laser cooled rubidium atoms will be used as the matter wave source. The atom optical elements will be microfabricated amplitude transmission gratings which will be used in a three-grating interferometer to split and recombine the rubidium beam. The interferometer will be a useful new tool for precision atomic physics and a sensitive inertial sensor.
Topics: DTIC Archive, McIntyre, David, OREGON STATE UNIV CORVALLIS, *ATOMS, *LASERS, TOOLS, SENSITIVITY,...
Topics: DTIC Archive, Caves, Carlton M, NEW MEXICO UNIV ALBUQUERQUE CENTER FOR ADVANCED STUDIES, *QUANTUM...
The goal of the MURI project is to advance matter wave sensors by combining atom interferometry with atom lasers and atom waveguides. This has the prospect of improving the sensitivity of such sensors by orders of magnitude as compared with existing state-of-the-art sensors. This final report summarizes major steps towards this goal, including the study of wave guides using atom chips, the demonstration of the novel method of contrast interferometry with Bose-Einstein condensates, and the...
Topics: DTIC Archive, Ketterie, Wolfgang, MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS,...
The TANAMI (Tracking AGN with Austral Milliarcsecond Interferometry) program provides comprehensive VLBI monitoring of extragalactic gamma-ray sources south of declination -30 degrees. Operating at two radio frequencies (8 and 22 GHz), this program is a critical component of the joint quasi-simultaneous observations with the Fermi Gamma-ray Space Telescope and ground based observatories to discriminate between competing theoretical blazar emission models. We describe the TANAMI program and...
Topics: DTIC Archive, NAVAL OBSERVATORY WASHINGTON DC, *GAMMA RAYS, *RADIOFREQUENCY, *INTERFEROMETRY,...
The newly completed Fourth USNO CCD Astrographic Catalog (UCAC4) has proven to be a rich source of double star astrometry and photometry. Following initial comparisons of UCAC4 results against those obtained by speckle interferometry, the UCAC4 catalog was matched against known double stars in theWashington Double Star Catalog in order to provide additional differential astrometry and photometry for these pairs. Matches to 58,131 pairs yielded 61,895 astrometric and 68,935 photometric...
Topics: DTIC Archive, NAVAL OBSERVATORY WASHINGTON DC, *BINARY STARS, CATALOGS, PHOTOMETRY, SPECKLE...
The Third Catalog of Interferometric Measurements of Binary Stars includes all published measures of binary and multiple star systems obtained by high-resolution techniques (speckle interferometry, photoelectric occultation timings, etc.), as well as negative examinations for duplicity, as of 2001 January 1. This catalog is one of four USNO double star catalogs to be included on a new CD-ROM. A brief summary and statistical analysis of the contents of the catalog are presented.
Topics: DTIC Archive, NAVAL OBSERVATORY WASHINGTON DC, *BINARY STARS, CATALOGS, HIGH RESOLUTION,...
A new feature of optical free induction decay (FID) is observed in a coherently prepared sample of 13CH3F by the method of Stark switching. The preparative phase is due to the resonant steady state excitation by a cw laser beam and is followed by FID upon sudden application of a d.c. Stark field that switches the molecular sample out of resonance. The emission is not observed as a simple decay but instead appears as a train of sharp pulses regularly spaced in time due to a repetitive...
Topics: DTIC Archive, Foster,K L, IBM RESEARCH LAB SAN JOSE CALIF, *MOLECULAR SPECTROSCOPY, *STARK EFFECT,...
Double-exposure specklegrams were made of aluminum 2024-T4 rectangular plates. The double-exposure speckle technique was applied to the aluminum plate to measure in-plane translation and rotation and out-of-plane tilt. Strain and vibrational analyses were also conducted. The vibrational results were compared with results previously obtained using double-exposure time average holography to ascertain their applicability to Naval Engineering. Background in Fourier transforms, wave theory,...
Topics: DTIC Archive, Lerchbacker,Alan Bernard, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *OPTICAL DETECTION,...
The fringe pattern produced by a Mach-Zehnder interferometer illuminated with the light from a hydrogen fluoride (HF) laser operating on a large number of laser lines was investigated. Emphasis was placed on the intensity variations of the infrared fringes that are observed when one element of the interferometer is translated, thereby changing the length of one optical path. An intensity maximum similar to 'white-light fringes' is observed when the two arms of the interferometer have equal...
Topics: DTIC Archive, Gross, R W, AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB, *INTERFEROMETRY, *SPECTRAL...
Lunar laser ranging (LLR) observations made by the McDonald Observatory from 1970 through 1980 have been analyzed to estimate the variation of latitude and Universal Time (UT). We have compared these estimates with determinations of earth rotation from other techniques. For observations obtained in two one-week periods in September and October 1980, during the International 'MERIT' (Measurement of Earth Rotation and Intercomparison of Techniques) Short Campaign, the root-mean-square difference...
Topics: DTIC Archive, Herring,T A, MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF EARTH AND PLANETARY...
The most recent solution of Earth Orientation Parameters (EOP) from the observations made by optical astrometry from 1899.7 to 1992.0 at 33 observatories is used to estimate the corrections of the present International Astronomical Union (IAU) model of precession-nutation. Since the resolution of the solution is about 5 days, only the terms with periods of 14 days and longer are considered. The results are compared with Very Long Baseline Interferometry-based corrections of the standard...
Topics: DTIC Archive, Vondrak, Jan, ACADEMY OF SCIENCES OF THE CZECH REPUBLIC PRAGUE ASTRONOMICAL INST,...
This report covers results addressing multi-scale measurements of deformation, strain, and failure behavior in particulate composites containing nano size particles. In addition, techniques are developed, based on multi-scale modeling approaches, to model particles interaction, damage initiation and evolution processes, and constitutive and crack growth behavior in particulate composites. The program's basic approach involves a blend of numerical and experimental studies. The results of these...
Topics: DTIC Archive, Liu, Chi T, AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV,...
This paper serves to elucidate the mathematical steps needed to apply near-field imaging over a significant (angular) area of regard, with specific application to the receiving sites of the Air Force Space Surveillance System (AFSSS, Space Fence). Cornwell has developed the mathematical formalism to merge near-field imaging with imaging over a wide field of view. The traditional far-field, narrow field-of-view imaging developed in radio astronomy can be extended to wide fields of view by taking...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV, *RADIO ASTRONOMY, *RADIO...
A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67 pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than...
Topics: DTIC Archive, NAVAL OBSERVATORY WASHINGTON DC, *BINARY STARS, ACCELERATION, ADAPTIVE OPTICS,...
We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100-450 solar Mass and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the...
Topics: NASA Technical Reports Server (NTRS), BLACK HOLES (ASTRONOMY), GRAVITATIONAL WAVES, STELLAR MASS,...
The gamma-ray satellite Fermi and the ground based TeV facilities MAGIC, VERITAS and HESS have ushered in a new era in the observation of high-energy emission from active galaxies. The energy budgets of these objects have a major contribution from gamma-rays and it is simply not possible to understand their physics without high-energy observations. Though the exact mechanisms for high-energy production in galaxies remains an open question, gamma-rays typically result from interactions between...
Topics: NASA Technical Reports Server (NTRS), ACTIVE GALAXIES, GALACTIC RADIATION, GAMMA RAYS, RADIO...
QuakeSim 2.0 improves understanding of earthquake processes by providing modeling tools and integrating model applications and various heterogeneous data sources within a Web services environment. QuakeSim is a multisource, synergistic, data-intensive environment for modeling the behavior of earthquake faults individually, and as part of complex interacting systems. Remotely sensed geodetic data products may be explored, compared with faults and landscape features, mined by pattern analysis...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, DATA BASES, DATA PROCESSING,...
This volume of reports is the 2013 Annual Report of the International VLBI Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS. The IVS 2013 Annual Report documents the work of the IVS components for the calendar year 2013, our fifteenth year of existence. The reports describe changes, activities, and progress of the IVS. Many thanks to all IVS...
Topics: NASA Technical Reports Server (NTRS), VERY LONG BASE INTERFEROMETRY, ASTROMETRY, GEODESY,...
Visibility measurements with Michelson interferometers, particularly the measurement of fringe contrast, are affected by various atmospheric and instrumental effects, all of which reduce the measured contrast. To compensate for this, stars with known or predictable diameters (calibrators) are observed so that the overall reduction in the visibility can be measured. Objects with the smallest possible diameters are preferred as calibrators, since the predicted visibilities become less sensitive...
Topics: DTIC Archive, Yoon, Jinmi, STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF PHYSICS AND ASTRONOMY,...
The role of microstructure in the dynamic deformation and fracture of a dual phase, polycrystalline tungsten alloy under highrate impact loading is investigated via experiments and modeling. The material studied consists of pure tungsten crystals embedded in a ductile binder alloy comprised of tungsten, nickel, and iron. The tungsten crystals are elongated in a preferred direction of extrusion during processing. Plate impact tests were conducted on samples oriented either perpendicular or...
Topics: DTIC Archive, Vogler, T J, ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS...
Optical fiber infrasound sensors (OFIS) are long compliant tubes wrapped with two optical fibers that integrate pressure variation along the length of the tubes via laser interferometry at the speed of light. We have previously shown that several OFIS arms can resolve the back azimuth and elevation angle of infrasound signals due to the spectral fingerprint of the instrument response in the recorded signal and the time separation provided by separating the centers of each OFIS arm. In this...
Topics: DTIC Archive, CALIFORNIA UNIV SAN DIEGO LA JOLLA, *FIBER OPTICS TRANSMISSION LINES,...
The general correlation principles for spectra and spectra derivatives are studied by using the Fourier transform of the spectral distribution of energy from a source illuminating a double beam interferometer with transverse splitting by dividing luminance. In this correlation technique, the use of such an interferometer has the advantage of greater luminosity as compared with a slit spectrometer. However, the correlation example indicates that it is necessary to adapt the correlator to the...
Topics: NASA Technical Reports Server (NTRS), AIR POLLUTION, INTERFEROMETRY, LUMINANCE, SPECTRAL...
Recommendations are presented for a global network of 125 sites for geodetic measurements by satellite laser ranging and very long baseline interferometry. The sites were proposed on the basis of existing facilities and scientific value for investigation of crustal dynamics as related to earthquake hazards. Tectonic problems are discussed for North America peripheral regions and for the world. The sites are presented in tables and maps, with bibliographic references.
Topics: NASA Technical Reports Server (NTRS), EARTH CRUST, GEODETIC SURVEYS, GEODYNAMICS, TECTONICS,...
An account is made of some of the applications of holographic interferometry to the visualization of transonic flows. In the case of the compressor shock visualization, the method is used regularly and has moved from being a research department invention to a design test tool. With the implementation of automatic processing and simple digitization systems, holographic vibrational analysis has also moved into routine nondestructive testing. The code verification interferograms were instructive,...
Topics: NASA Technical Reports Server (NTRS), AIR FLOW, FLOW VISUALIZATION, HOLOGRAMMETRY, HOLOGRAPHIC...
By arguing that the limiting noise is the photoelectron shot noise, we show that the sensitivity of image synthesis by an ideal optical interferometer is independent of the details of beam-splitting and recombination. The signal-to-noise ratio of the synthesized image is proportional to the square root of the total number of photoelectrons detected by the entire array. For non-ideal interferometers, which are forced to employ a closure-phase method of indirect inference of the visibility data,...
Topics: NASA Technical Reports Server (NTRS), BEAM SPLITTERS, INTERFEROMETERS, INTERFEROMETRY,...
In Part 1 of this two-part article, an error budget is presented for Earth-based delta differential one-way range (delta DOR) measurements between two spacecraft. Such observations, made between a planetary orbiter (or lander) and another spacecraft approaching that planet, would provide a powerful target-relative angular tracking data type for approach navigation. Accuracies of better than 5 nrad should be possible for a pair of spacecraft with 8.4-GHz downlinks, incorporating 40-MHz DOR tone...
Topics: NASA Technical Reports Server (NTRS), ERROR ANALYSIS, INTERPLANETARY NAVIGATION, ORBITAL POSITION...
Testing and analysis of shock wave characteristics such as detonators and ground shock propagation frequently require a method of measuring velocity and displacement of the surface of interest. One method of measurement is Doppler interferometry. The VISAR (Velocity Interferometer System for Any Reflector) uses Doppler interferometry and has gained wide acceptance as the preferred tool for shock measurement. An important asset of VISAR is that it measures velocity and displacement...
Topics: NASA Technical Reports Server (NTRS), DETONATION WAVES, DETONATORS, FIBER OPTICS, INTERFEROMETERS,...
Our objectives were to use modem geodetic data, especially those derived from space techniques like Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and the Global Positioning System (GPS) to infer crustal deformation in southern California and relate it to plate tectonics and earthquake hazard. To do this, we needed to collect some original data, write computer programs to determine positions of survey markers from geodetic observables, interpret time dependent...
Topics: NASA Technical Reports Server (NTRS), CALIFORNIA, CRUSTAL FRACTURES, DEFORMATION, EARTHQUAKES,...
The preliminary analysis of the C-band cross-track interferometric data (XTI) acquired during the MAC Europe 1991 campaign over the Matera test site, in Southern Italy is presented. Twenty three passive calibrators (Corner Reflector, CR) and 3 active calibrators (Active Radar Calibrator, ARC) were deployed over an area characterized by homogeneous background. Contemporaneously to the flight, a ground truth data collection campaign was carried out. The research activity was focused on the...
Topics: NASA Technical Reports Server (NTRS), C BAND, GROUND TRUTH, IMAGE ANALYSIS, RADAR CORNER...
An orbiting radio telescope is proposed which, when operated in a very long baseline interferometry (VLBI) scheme, would allow higher than currently available angular resolution and dynamic range in the maps and the ability to observe rapidly changing astronomical sources. Using passive phased array technology, the proposed design consists of 656 hexagonal modules forming a 150-m diameter antenna dish. Each observatory module is largely autonomous, having its own photovoltaic power supply and...
Topics: NASA Technical Reports Server (NTRS), ANTENNA ARRAYS, PHASED ARRAYS, RADIO TELESCOPES, SPACEBORNE...
