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250
May 21, 2011
05/11
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Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhik
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Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.
Topics: ATMOSPHERIC SOUNDING, CARBON DIOXIDE LASERS, CONTROL EQUIPMENT, DESIGN ANALYSIS, FAULT TOLERANCE,...
411
411
Jul 26, 2010
07/10
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Baker, Karl W.; Dustin, Miles O.; Crane, Roge
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An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the...
Topics: ATMOSPHERIC CIRCULATION, CORRECTION, FLIGHT TESTS, JIMSPHERE BALLOONS, KALMAN FILTERS, MACH NUMBER,...
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500
Sep 20, 2010
09/10
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Bansal, Narottam P
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The applications of chronopotentiometry to the study of electrochemical behavior of three technologically important areas of refractory metals, actinides, and oxyanions in molten salts are critically reviewed. Chronopotentiometry is a very versatile diagnostic tool to understand the reaction mechanism of the electrode processes for the electrochemical reduction/oxidation of these electroactive species in molten salt solutions. Well adherent, compact, and uniformly thick coatings of refractory...
Topics: AEROSOLS, ATMOSPHERIC COMPOSITION, REMOTE SENSING, SATELLITE OBSERVATION, WIND MEASUREMENT,...
472
472
Jul 11, 2010
07/10
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Baranov, A. V.; Liberzon, E. A.; Popova, T. I
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A study was made of the composition of the liquid phase formed upon absorption of nitrogen dioxide by sulfuric acid as a function of the concentration of oxides in the gas, temperature and concentration of sulfuric acid. It was found that in the process of absorption of NO2, mixtures consisting of HNO3 HNOSO4 H2SO4 H2O are formed, containing quite definite maximum concentrations of HNOSO4, dependent on temperature, NO2 concentration in the gas and concentration of absorbing sulfuric acid. This...
Topics: REMOTE SENSORS, TEMPERATURE MEASUREMENT, WIND MEASUREMENT, CRYSTAL OSCILLATORS, HEATING EQUIPMENT,...
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199
May 23, 2011
05/11
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Blanchard, R. C.; Ozoroski, Thomas A.; Nicholson, John Y
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Calibrated pressure measurements for species with mass-to-charge ratios up to 50 amu/e(-) were obtained trom the shuttle upper atmosphere mass spectrometer experiment during re-entry on the STS-35 mission. The principal experimental objective is to obtain measurements of freestream density in the hypersonic rarefied flow flight regime. Data were collected from 180 to about 87 km. However, data above 115 km were contaminated from a source of gas emanating from pressure transdueers connected in...
Topics: ERROR ANALYSIS, WIND MEASUREMENT, VORTICITY, TEMPERATURE GRADIENTS, HORIZONTAL ORIENTATION,...
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200
May 21, 2011
05/11
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Bokhari, Shahid H
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Parametric Binary Dissection (PBD) is a new algorithm that can be used for partitioning graphs embedded in 2- or 3-dimensional space. It partitions explicitly on the basis of nodes (lambda)x(edges cut), where lambda is the ratio of time to communicate over an edge to the time to compute at a node. The new algorithm is faster than the original binary dissection algorithm and attempts to obtain better partitions than the older algorithm, which only takes nodes into account. The performance of...
Topics: MICROWAVE SCATTERING, PROBABILITY THEORY, SCATTEROMETERS, OCEAN SURFACE, RAIN, WIND MEASUREMENT,...
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347
May 27, 2011
05/11
by
Charlton, Eric F
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Aerodynamic analysis are performed using the Lockheed-Martin Tactical Aircraft Systems (LMTAS) Splitflow computational fluid dynamics code to investigate the computational prediction capabilities for vortex-dominated flow fields of two different tailless aircraft models at large angles of attack and sideslip. These computations are performed with the goal of providing useful stability and control data to designers of high performance aircraft. Appropriate metrics for accuracy, time, and ease of...
Topics: MONSOONS, VORTICITY, TROPICAL REGIONS, WIND MEASUREMENT, TEMPERATE REGIONS, SEA SURFACE...
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267
May 23, 2011
05/11
by
Ciancone, Michael L.; Havenhill, Maria T.; Terlep, Judith A
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Spaceflight Safety (SFS) engineers at NASA Lewis Research Center (LeRC) are responsible for evaluating the microgravity fluids and combustion experiments, payloads and facilities developed at NASA LeRC which are manifested for spaceflight on the Space Shuttle, the Russian space station Mir, and/or the International Space Station (ISS). An ongoing activity at NASA LeRC is the comprehensive training of its SFS engineers through the creation and use of safety tools and processes. Teams of SFS...
Topics: MICROMECHANICS, THERMOSPHERE, MESOSPHERE, MICROMINIATURIZATION, MICROELECTRONICS, ELECTROMECHANICS,...
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293
May 23, 2011
05/11
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Coats, Timothy Willia
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An investigation of translaminate fracture and a progressive damage methodology was conducted to evaluate and develop a residual strength prediction capability for laminated composites with through penetration notches. This is relevant to the damage tolerance of an aircraft fuselage that might suffer an in-flight accident such as an uncontained engine failure. An experimental characterization of several composite materials systems revealed an R-curve type of behavior. Fractographic examinations...
Topics: OPTICAL RADAR, COMPUTERIZED SIMULATION, WIND SHEAR, SPATIAL DISTRIBUTION, COVARIANCE, WIND...
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May 23, 2011
05/11
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Dalgarno, A.; Fox, J. L
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There are many differences and also remarkable similarities between the ion chemistry and physics of planetary ionospheres and the ion chemistry and physics of astronomical environments beyond the solar system. In the early Universe, an expanded cooling gas of hydrogen and helium was embedded in the cosmic background radiation field and ionized by it. As the Universe cooled by adiabatic expansion, recombination occurred and molecular formation was driven by catalytic reactions involving the...
Topics: BRIGHTNESS TEMPERATURE, LOOK ANGLES (ELECTRONICS), MICROWAVE SIGNATURES, POLARIZATION (WAVES), WIND...
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230
May 31, 2011
05/11
by
Dimofte, Florin; Keith, Theo G., Jr
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Over the 70-year evolution of the helicopter, man's understanding of vibration control has greatly increased. However, in spite of the increased performance, the extent of helicopter vibration problems has not significantly diminished. Crew vibration and noise remains important factors in the design of all current helicopters. With more complex and critical demands being placed on aircrews, it is essential that vibration and noise not impair their performance. A major source of helicopter cabin...
Topics: WEATHER FORECASTING, WIND MEASUREMENT, WIND DIRECTION, SPACECRAFT LAUNCHING, DATA PROCESSING, WIND...
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252
Jun 2, 2011
06/11
by
DiVito, Ben L
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eye 252
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We describe an approach to strategy-based proving for improved interactive deduction in specialized domains. An experimental package of strategies (tactics) and support functions called Manip has been developed for PVS to reduce the tedium of arithmetic manipulation. Included are strategies aimed at algebraic simplification of real-valued expressions. A general deduction architecture is described in which domain-specific strategies, such as those for algebraic manipulation, are supported by...
Topics: WIND MEASUREMENT, SPACECRAFT LAUNCHING, GROUND OPERATIONAL SUPPORT SYSTEM, WIND VELOCITY,...
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344
Jun 3, 2011
06/11
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Doggett, Willia
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eye 344
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Many initiatives under study by both the space science and earth science communities require large space systems, i.e. with apertures greater than 15 m or dimensions greater than 20 m. This paper reviews the effort in NASA Langley Research Center's Automated Structural Assembly Laboratory which laid the foundations for robotic construction of these systems. In the Automated Structural Assembly Laboratory reliable autonomous assembly and disassembly of an 8 meter planar structure composed of 102...
Topics: DOPPLER RADAR, DATA PROCESSING, WIND PROFILES, TROPOSPHERE, YLF LASERS, SIGNAL PROCESSING, HOLMIUM,...
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346
Jun 18, 2010
06/10
by
Dunaway, G. L
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eye 346
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Ballistic factors, balloon measured wind data, and impact predictions for Aerobee rocket launch
Topics: AEROBEE ROCKET VEHICLE, BALLISTICS, BALLOON SOUNDING, IMPACT PREDICTION, BALLISTICS, BALLOON...
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514
Jul 5, 2010
07/10
by
Fodchuk, V. I
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eye 514
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No Abstract Available
Topics: EUROPEAN SPACE PROGRAMS, ITALY, ROCKET SOUNDING, UPPER ATMOSPHERE, ARTIFICIAL CLOUDS, WIND...
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409
May 29, 2011
05/11
by
Geng, Steven M.; Schwarze, Gene E.; Niedra, Janis M
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The NASA Glenn Research Center and the Department of Energy (DOE) are developing advanced radioisotope Stirling convertors, under contract with Stirling Technology Company (STC), for space applications. Of critical importance to the successful development of the Stirling convertor for space power applications is the development of a lightweight and highly efficient linear alternator. This paper presents a 3-D finite element method (FEM) approach for evaluating Stirling convertor linear...
Topics: GLOBAL POSITIONING SYSTEM, ALGORITHMS, RECEIVERS, EXPERIMENT DESIGN, DATA REDUCTION, GROUND WIND,...
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138
Jul 11, 2010
07/10
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GURIN, L. S.; IVANOVA, N. P.; MOKROV, V. S.; TSOY, K. A
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VARIOUS METHODS ARE DISCUSSED FOR ESTIMATING THE PARAMETERS OF PARTICLE FLUXES REPRESENTING A POISSON PROCESS. THE PARTICLES ARRIVE, THROUGH SEVERAL FILTERS, AT A COMMON COUNTER WHICH TRANSMITS THE ARRIVAL TIME OF EACH EIGHTH PARTICLE. THE MIXING OF THE PARTICLES REDUCES THE ACCURACY WITH WHICH THE PARAMETERS ARE DETERMINED. THE EFFICIENCY OF THE ESTIMATION METHODS CONSIDERED IS COMPARED BY MEANS OF A THEORETICAL ANALYSIS AND MONTE CARLO SIMULATION MODELS USING ELECTRONIC DIGITAL COMPUTERS. THE...
Topics: ELECTRICITY, FRANCE, WINDMILLS (WINDPOWERED MACHINES), WINDPOWER UTILIZATION, ELECTRIC GENERATORS,...
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305
Jul 12, 2010
07/10
by
Harris, C. D.; Blackwell, J. A., Jr
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eye 305
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Wind tunnel tests were conducted at Mach numbers from 0.60 to 0.81 to examine the effects on supercritical airfoil of modifying the rear upper surface to reduce the magnitude of an intermediate off design second velocity peak. The modification was accomplished by increasing the upper surface curvature around the 50 percent chord station and reducing the curvature over approximately the rearmost 30 percent of the airfoil while maintaining the same trailing edge thickness.
Topics: BRAIN DAMAGE, IMAGING TECHNIQUES, JET ENGINE FUELS, WIND DIRECTION, WIND MEASUREMENT, CHILDREN,...
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183
May 22, 2011
05/11
by
Hyer, M. W.; Oleksuk, Lynda L. S.; Bowles, D. E
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To study the influence on overall deformations of the time-dependent constitutive properties of fiber-reinforced polymeric matrix composite materials being considered for use in orbiting precision segmented reflectors, simple sandwich beam models are developed. The beam models include layers representing the face sheets, the core, and the adhesive bonding of the face sheets to the core. A three-layer model lumps the adhesive layers with the face sheets or core, while a five-layer model...
Topics: CONTROL SYSTEMS DESIGN, VORTEX GENERATORS, WIND TUNNEL TESTS, WIND TURBINES, WINDPOWER UTILIZATION,...
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236
Jun 21, 2010
06/10
by
Kestenboym, Kh. S., et al
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eye 236
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Strong point explosion in exponential atmosphere without consideration of real properties of air
Topics: CROSS CORRELATION, WIND MEASUREMENT, PHOTOMETERS, PROBABILITY DENSITY FUNCTIONS, TURBULENT FLOW,...
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219
Jul 5, 2010
07/10
by
KONDRATYEV, K. Y.; ROMANTEYEV, N. F.; SMOKTIY, O. I.; KHRUNOV, Y. V
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THE AIRGLOW LAYER OBSERVED BY THE SPACECRAFT SOYUZ 5 IS DESCRIBED. THE USE OF THE AIRGLOW LAYER FOR NAVIGATIONAL PURPOSES IS POSTULATED ON THE BASIS OF SOYUZ 5, SOYUZ 9, AND ROCKET MEASUREMENTS.
Topics: CATEGORIES, HURRICANES, METEOROLOGICAL PARAMETERS, TORNADOES, FUJITA METHOD, SEA STATES, WIND...
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116
May 22, 2011
05/11
by
Kotz, David; Nieuwejaar, Nil
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eye 116
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Multiprocessors have permitted astounding increases in computational performance, but many cannot meet the intense I/O requirements of some scientific applications. An important component of any solution to this I/O bottleneck is a parallel file system that can provide high-bandwidth access to tremendous amounts of data in parallel to hundreds or thousands of processors. Most successful systems are based on a solid understanding of the expected workload, but thus far there have been no...
Topics: LANDING SITES, PRESSURE MEASUREMENT, TROPICAL REGIONS, WIND MEASUREMENT, LATITUDE, MARS ATMOSPHERE,...
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May 23, 2011
05/11
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Lakshmanan, B.; Abdol-Hamid, Khaled S
texts
eye 325
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Supersonic jet plumes were studied using a two-equation turbulence model employing corrections for compressible dissipation and pressure-dilatation. A space-marching procedure based on an upwind numerical scheme was used to solve the governing equations and turbulence transport equations. The computed results indicate that two-equation models employing corrections for compressible dissipation and pressure-dilatation yield improved agreement with the experimental data. In addition, the numerical...
Topics: OPTICAL RADAR, WIND MEASUREMENT, LASER APPLICATIONS, RADAR MEASUREMENT, RESEARCH AND DEVELOPMENT,...
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Jul 26, 2010
07/10
by
Lance, D. G.; Nettles, A. T
texts
eye 270
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A damage tolerance study of two new toughened carbon fiber/epoxy resin systems was undertaken as a continuation of ongoing work into screening new opposites for resistance to foreign object impact. This report is intended to be a supplement to NASA TP 3029 in which four new fiber/resin systems were tested for damage tolerance. Instrumented drop weight impact testing was used to inflict damage to 16-ply quasi-isotropic specimens. Instrumented output data and cross-sectional examinations of the...
Topics: ATMOSPHERIC LASERS, EARTH OBSERVING SYSTEM (EOS), SPACE SHUTTLE PAYLOADS, SPACE STATION POLAR...
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587
Jul 11, 2010
07/10
by
Leonov, A. A.; Lebedev, V. I
texts
eye 587
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Psychological compatibility among crew members of an interplanetary ship is examined under the conditions of group isolation, the extended effect of weightlessness on human mental processes, the effect of sensory and information starvation on the appearance of unusual mental states, emotional stress, and the rhythm of working and rest.
Topics: CLEAR AIR TURBULENCE, METEOROLOGICAL PARAMETERS, SYNOPTIC METEOROLOGY, MOUNTAINS, RAWINSONDES,...
This paper describes an approach which was used to predict Ares I-X launch vehicle structural airloads and controllability prior to launch. This prediction along with the proper application of protection for variations in key environment and trajectory parameters was used to predict the potential for the launch trajectory to stay within the integrated vehicle certification envelopes. This data was applied by the launch team as a key element of the launch day go/no-go recommendation. NASA s...
Topics: NASA Technical Reports Server (NTRS), ARES 1 LAUNCH VEHICLE, WIND MEASUREMENT, TRAJECTORIES,...
The 30 Weather Squadron (30 WS) is concerned about strong winds observed at their northern towers without advance warning. They state that terrain influences along the extreme northern fringes of Vandenberg Air Force Base (VAFB) make it difficult for forecasters to issue timely and accurate high wind warnings for northeasterly wind events. These events tend to occur during the winter or early spring when they are under the influence of the Great Basin high pressure weather regime. The Launch...
Topics: NASA Technical Reports Server (NTRS), WIND (METEOROLOGY), FORECASTING, METEOROLOGICAL CHARTS,...
Two mathematical representations of noise due to atmospheric turbulence are presented. These representations are derived and used in computer simulations of the Bartlett Estimate implementation of beamforming. Beamforming is an array processing technique employing an array of acoustic sensors used to determine the bearing of an acoustic source. Atmospheric wind conditions introduce noise into the beamformer output. Consequently, the accuracy of the process is degraded and the bearing of the...
Topics: NASA Technical Reports Server (NTRS), ACOUSTICS, ATMOSPHERIC CIRCULATION, ATMOSPHERIC TURBULENCE,...
A simple analytical microburst model was developed for use in estimating vertical winds from horizontal wind measurements. It is an axisymmetric, steady state model that uses shaping functions to satisfy the mass continuity equation and simulate boundary layer effects. The model is defined through four model variables: the radius and altitude of the maximum horizontal wind, a shaping function variable, and a scale factor. The model closely agrees with a high fidelity analytical model and...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT SAFETY, BOUNDARY LAYERS, MATHEMATICAL MODELS,...
Fundamental to improving the understanding of the total Earth system are increased and improved observations. In the coming decade several spaceborne instrumented platforms will be constructed and implemented. These platforms will, in large, be housing the NASA Earth Observing System (EOS) instrument suite. One of the proposed instruments is a wind profiling system which is currently referred to as the Laser Atmospheric Wind Sounder (LAWS). This instrument will use a CO2 Doppler lidar wind...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, DOPPLER RADAR, EARTH OBSERVING...
The purpose was to provide rocket-borne measurements of temperature and wind. These data are used to: obtain a better understanding of the processes that control the chemical and dynamic behavior of the stratospheric region; monitor temperature trends and detect changes; verify and monitor remote measurements (ground- and satellite-based); and provide density measurements for large space vehicle operations.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC SOUNDING, ATMOSPHERIC TEMPERATURE, DENSITY...
Laser Doppler radar (lidar) is widely used for remote sensing of wind velocities. Usable wavelengths for the laser are limited by the effects of atmospheric turbulence. An adaptive optical system is proposed to compensate for turbulence effects on signal power. The feasibility of an adaptive system is considered in light of the effects of speckle from the aerosol target. It is concluded that adaptive optics is a promising technique for improving the performance of a 2 micron lidar wind...
Topics: NASA Technical Reports Server (NTRS), ADAPTIVE OPTICS, ALGORITHMS, ATMOSPHERIC TURBULENCE, DOPPLER...
The feasibility is examined of a network of clear air radar wind profilers to forecast wind conditions before Space Shuttle launches during winter. Currently, winds are measured only in the vicinity of the shuttle launch site and wind loads on the launch vehicle are estimated using these measurements. Wind conditions upstream of the Cape are not monitored. Since large changes in the wind shear profile can be associated with weather systems moving over the Cape, it may be possible to improve...
Topics: NASA Technical Reports Server (NTRS), METEOROLOGICAL RADAR, SPACECRAFT LAUNCHING, WIND DIRECTION,...
Accurate, global profiling of wind velocity is highly desired by NASA, NOAA, the DOD/DOC/NASA Integrated Program Office (IPO)/NPOESS, DOD, and others for many applications such as validation and improvement of climate models, and improved weather prediction. The most promising technology to deliver this measurement from space is Doppler Wind Lidar (DWL). The NASA/NOAA Global Tropospheric Wind Sounder (GTWS) program is currently in the process of generating the science requirements for a...
Topics: NASA Technical Reports Server (NTRS), DOPPLER RADAR, OPTICAL RADAR, TRADEOFFS, WIND VELOCITY,...
Measurements of wind direction and speed, vertical velocity, and temperature were made from several levels of the 444 m tower near Oklahoma City. Turbulence quantities were calculated from the covariances between observed variables over periods ranging from 5 min to 1 hr. It was found that in some cases parameters such as mean wind speed, shearing stress, and vertical heat flux could be expressed by simple equations for periods of 15 min to 1 hr. Changes in these quantities with time are...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC TURBULENCE, WIND MEASUREMENT, ATMOSPHERIC...
An analysis of data collected in a hurricane research program is presented. The data were collected with a Synthetic Aperture Radar (SAR) during five aircraft flights in the Atlantic in August and September, 1976. Work was conducted in two areas. The first is an analysis of the L-band SAR data in a scatterometer mode to determine the surface windspeeds in hurricanes, in a similar manner to that done by an X-band scatterometer. The second area was to use the SAR to examine the wave patterns in...
Topics: NASA Technical Reports Server (NTRS), HURRICANES, SYNTHETIC APERTURE RADAR, WIND MEASUREMENT,...
The effect of the external wind on the quality of the flow in the test section was studied. The flow quality achievable with the complex treatment as well as that with the planned minimum treatment system is discussed. A scale model coupled with on site wind measurements demonstrated that the minimum treatment selected can provide adequate testing capabilities in the presence of the prevailing local winds, and that test programs will not be significantly affected by adverse wind effects on the...
Topics: NASA Technical Reports Server (NTRS), FLOW MEASUREMENT, INTAKE SYSTEMS, NASA PROGRAMS, WIND...
An exploratory wind survey at an antenna complex was summarized statistically for application to future windmill designs. Data were collected at six locations from a total of 10 anemometers. Statistics include means, standard deviations, cubes, pattern factors, correlation coefficients, and exponents for power law profile of wind speed. Curves presented include: mean monthly wind speeds, moving averages, and diurnal variation patterns. It is concluded that three of the locations have...
Topics: NASA Technical Reports Server (NTRS), ANEMOMETERS, STATISTICAL ANALYSIS, WIND MEASUREMENT, WIND...
A computational model for the determination of the detailed plasma and magnetic field properties of the global interaction of the solar wind with nonmagnetic terrestrial planetary obstacles is described. The theoretical method is based on an established single fluid, steady, dissipationless, magnetohydrodynamic continuum model, and is appropriate for the calculation of supersonic, super-Alfvenic solar wind flow past terrestrial ionospheres.
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELDS, SOLAR WIND, TERRESTRIAL PLANETS,...
The problem of very short-range forecasting is twofold. It is necessary to understand the processes that are being forecasted, and data appropriate to the scale of interest has to be generated. Coherent VHF and UHF radars are being used for operational wind profiling and are providing part of the solution to the data-acquisition problem. The Profiler system operated by the Wave Propagation Laboratory at NOAA has already shown great promise. As a result, plans are being considred for expanding...
Topics: NASA Technical Reports Server (NTRS), COHERENT RADAR, SPACETENNAS, ULTRAHIGH FREQUENCIES, VERY HIGH...
The reduction of spaced wind measurements taken over a range of heights is described. The equipment used is a medium frequency radar with one site consisting of a vertically pointing transmitter and space receiving antennas, and two remote receiving sites with spaced antennas. Assuming approximately horizontally stratified scatterers, horizontal winds are thus available at the corners of a triangle of side approx. 20 km in the GRAVNET system.
Topics: NASA Technical Reports Server (NTRS), GRAVITY WAVES, HORIZONTAL ORIENTATION, METEOROLOGICAL RADAR,...
Considerable progress with coherent laser radar has been made over the last few years, most notably perhaps in the available range of high performance devices and components and the confidence with which systems may now be taken into the field for prolonged periods of operation. Some of this increasing maturity was evident at the 3rd Topical Meeting on Coherent Laser Radar: Technology and Applications. Topics included in discussions were: mesoscale wind fields, nocturnal valley drainage and...
Topics: NASA Technical Reports Server (NTRS), COHERENT RADAR, LASER APPLICATIONS, OPTICAL RADAR,...
The spectral width of the Doppler radar echo has been used to estimate the atmospheric turbulence parameters because it is directly related to the kinetic energy contained in the turbulence. However, sufficient care must be taken in deriving the turbulence parameters since the measured spectral width can be easily affected by undesired factors such as beam broadening, shear broadening, and the temporal variation of the wind field. Here researchers examine these factors in the case of the MU...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC SOUNDING, ATMOSPHERIC TURBULENCE, BEAMS...
A planned airborne lidar system is presented which is intended to provide a remote sensing facility for a variety of applications. The eventual goal of the system development is a Doppler wind measurement capability for boundary layer dynamics and cloud physics applications. The first stage of development is focused initially on a direct detection lidar to measure aerosol profiles and depolarization from cloud backscatter. Because of the Doppler goal, interest in larger particles to define the...
Topics: NASA Technical Reports Server (NTRS), AIRBORNE LASERS, CLOUD PHYSICS, INFRARED RADAR, OPTICAL...
Spaceflight applications for the NASA Scatterometer (NSCAT) , an ocean surface wind measuring system flown as part of the Navy Remote Ocean Sensing System (NROSS) are discussed in outline form, along with information on the Advanced Digital Synthetic aperture radar Processor (ADSP) that is being developed for ground-based processing of spacecraft Earth observations. Design considerations are listed. A block diagram of the scatterometer is given.
Topics: NASA Technical Reports Server (NTRS), AIRBORNE/SPACEBORNE COMPUTERS, DATA TRANSMISSION,...
Recently, our group mapped the CO absorption lines on the disk of Venus in 1988 using the synthetic aperture array at the Owens Valley Radio Observatory. Observations were make in the (0-1) rotational transition of CO at 115 GHz, or a wavelength of 2.6 mm. Systematic variations in the Doppler shifts of the lines (particularly near the limbs) enable the group to directly map the wind field at 100 plus or minus 10 km, the peak altitude for the experimental weighting functions used. These...
Topics: NASA Technical Reports Server (NTRS), BULGING, CARBON MONOXIDE, CLOUD HEIGHT INDICATORS, SYNTHETIC...
The objective of the study was to identify and model major sources of short-term pointing jitter for a free-flying, full performance 2 micron LAWS system and evaluate the impact of the short-term jitter on wind-measurement performance. A fast steering mirror controls system was designed for the short-term jitter compensation. The performance analysis showed that the short-term jitter performance of the controls system over the 5.2 msec round-trip time for a realistic spacecraft environment was...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, ATMOSPHERIC SOUNDING, CONTROL...
NASA Langley Research Center has a long history of developing 2-micron laser transmitter for wind sensing. With support from NASA Laser Risk Reduction Program (LRRP) and Instrument Incubator Program (IIP), NASA Langley Research Center has developed a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement. The transmitter portion of the transceiver employs the high-pulse-energy, Ho:Tm:LuLiF, partially conductively cooled laser technology...
Topics: NASA Technical Reports Server (NTRS), DOPPLER RADAR, LASER APPLICATIONS, METEOROLOGICAL RADAR,...
The hazards of landfalling hurricanes are well known, but progress on improving the intensity forecasts of these deadly storms at landfall has been slow. Many cite a lack of high-resolution data sets taken inside the core of a hurricane, and the lack of reliable measurements in extreme conditions near the surface of hurricanes, as possible reasons why even the most state-of-the-art forecasting models cannot seem to forecast intensity changes better. The Hurricane Imaging Radiometer (HIRAD) is a...
Topics: NASA Technical Reports Server (NTRS), HURRICANES, MESOMETEOROLOGY, MESOSCALE PHENOMENA, REMOTE...
The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with...
Topics: NASA Technical Reports Server (NTRS), CLIMATE CHANGE, POLAR REGIONS, SATELLITE OBSERVATION, REMOTE...
