Search NASA⌕ Search

SEARCH · Search NASA

Results for “Austin”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Soil Moisture Data for TRACER project (Houston, TX)

The purpose of this study was to collect and distribute ground-truth soil water content and meteorological data in the Houston, TX, area, supporting the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facility, and the 2022 field campaign for the Tracking Aerosol Convection Interactions ExpeRiment (TRACER). The files herein contain soil water content and meteorological data for three stations that the Bureau of Economic Geology at UT Austin installed in the Houston, TX, area during the period of performance. The data includes soil moisture, volumetric water content, electrical conductivity of soil, soil temperature, rain precipitation, air temperature and other parameters. Data files within this data set contain measurements at both sub-hourly and 1-hour resolution measurements. The sub-hourly meteorological data file names end with “TRACER_SubHourly_met.dat”, and the sub-hourly soil data files end with “TRACER_SubHourly_soil.dat”. For the 1-hour resolution data, the files ending with "_Soil_flagged.dat” contain mean hourly volumetric soil water content and temperature measured at 5, 10, 20 and 50 cm depths. The files ending with “_Meteoro_flagged.dat” contain mean hourly measured precipitation, air temperature and humidity, wind speed and direction, and solar radiation. All data have undergone QA/QC procedures that are described by Caldwell et al. (2019) and Dorigo et al. (2013) for the soil-specific data, and EPA (2008) for the meteorological data.

Air temperature↗
NASA NTRS1971

Subsurface discontinuity detection by microwave radiometry.

Brief description of a joint program undertaken near Austin and San Antonio, Tex., to detect the presence of subsurface voids such as caverns and tunnels by microwave radiometry. Mi crowave radiometric temperature measurements using both vertical and horizontal polarization were taken with fixed-view angle traverses across three sites at two locations. No unambiguous correlation between the microwave temperature contours and the subsurface voids was observed at either location, but a correlation between microwave temperature and moisture patterns was observed at both locations. The large microwave temperature anomalies observed at all three sites indicated a sensitivity to near-surface structure and moisture distribution. A close correlation was noted between low soil-bearing strength values and the tunnel location at the San Antonio site.

Hruby, R. J.↗
NASA NTRS1972

Observations of the total lunar eclipse on February 10, 1971 at 3.1 mm wavelength.

Observations were made of the total lunar eclipse on February 10, 1971 at a wavelength of 3.1 mm at the Millimeter Wave Observatory of the University of Texas at Austin. Eclipse cooling curves obtained for Copernicus, Mare Serenitatis, and a mountainous region indicate maximum temperature decreases of 6.77%, 6.37%, and 7.51%, respectively. Cooling rates of about 6 K/hour were measured. The normalized solar insolation has also been calculated for each region.

Ulich, B. L.↗
NASA NTRS1977

Urban area delineation and detection of change along the urban-rural boundary as derived from LANDSAT digital data

LANDSAT digital multispectral scanner data, in conjunction with supporting ground truth, were investigated to determine their utility in delineation of urban-rural boundaries. The digital data for the metropolitan areas of Washington, D. C.; Austin, Texas; and Seattle, Washingtion; were processed using an interactive image processing system. Processing focused on identification of major land cover types typical of the zone of transition from urban to rural landscape, and definition of their spectral signatures. Census tract boundaries were input into the interactive image processing system along with the LANDSAT single and overlayed multiple date MSS data. Results of this investigation indicate that satellite collected information has a practical application to the problem of urban area delineation and to change detection.

Christenson, J. W.↗
NASA NTRS1978

Baseline tests of the Kordesh hybrid passenger vehicle

Performance test results are presented for a four-passenger Austin A40 sedan that was converted to a heat-engine-alternator-and battery-powered hybrid. It is propelled by a conventional, gasoline-fueled, heat-engine-driven alternator and a traction pack powering a series-wound, 10 hp direct-current electric drive motor. The 16 hp gasoline engine drives the 7 kilowatt alternator, which provides electrical power to the drive motor or to the 96 volt traction battery through a rectifier. The propulsion battery consists of eight 12 volt batteries connected in series. The electric motor is coupled to a four-speed standard transmission, which drives the rear wheels. Power to the motor is controlled by a three-step foot throttle, which actuates relays that control armature current and field excitation. Conventional hydraulic brakes are used.

Soltis, R. F.↗
NASA NTRS1978

The McDonald Observatory lunar laser ranging project

A summary of the activities of the McDonald lunar laser ranging station at Fort Davis for the FY 77-78 fiscal year is presented. The lunar laser experiment uses the observatory 2.7m reflecting telescope on a thrice-per-day, 21-day-per-lunation schedule. Data are recorded on magnetic tapes and sent to the University of Texas at Austin where the data is processed. After processing, the data is distributed to interested analysis centers and later to the National Space Science Data Center where it is available for routine distribution. Detailed reports are published on the McDonald operations after every fourth lunation or approximately once every 115 days. These reports contain a day-by-day documentation of the ranging activity, detailed discussions of the equipment development efforts, and an abundance of other information as is needed to document and archive this important data type.

Silverberg, E. C.↗
NASA NTRS1978

CTS attenuation and cross polarization measurements at 11.7 GHz

The results of data obtained at The University of Texas at Austin during a total of 551 days of righthand circularly polarized transmission at 11.7 GHz from the CTS satellite are presented. Measured were attenuation, cross-polarization and rain rate. Results indicate that ice depolarization can be of significant importance.

Vogel, W. J.↗
NASA NTRS1979

CTS attenuation and cross polarization measurements at 11.7 GHz

Attenuation and cross-polarization isolation at 11.7 GHz, measured at Austin, Texas by receiving the circularly polarized emissions from the CTS satellite are presented. A 12 month summary for Feb 78 to Jan 79 is presented. For .016 percent of the time the attenuation was greater than 10 dB, the isolation was less than 21 dB and the rainrate exceeded 55 mm/hr. Ice depolarization was observed frequently.

Vogel, W. J.↗
NASA NTRS1980

CTS attenuation and cross polarization measurements at 11.7 GHz

The long-term attenuation, cross-polarization, and rain-rate data monitored in Austin, Texas from the circularly polarized 11.7 GHz satellite beacon transmitter aboard the Communications Technology Satellite are analyzed. Data events are significantly more likely during April-September, than during October-March, except for ice deplorization which predominates during the winter months. A time of day dependence of the events is also noted. The 10 dB fade level is exceeded for .03% during the thunderstorm months. Isolation with the same probability is 23 dB.

Vogel, W. J.↗
NASA NTRS1978

LANDSAT image differencing as an automated land cover change detection technique

Image differencing was investigated as a technique for use with LANDSAT digital data to delineate areas of land cover change in an urban environment. LANDSAT data collected in April 1973 and April 1975 for Austin, Texas, were geometrically corrected and precisely registered to United States Geological Survey 7.5-minute quadrangle maps. At each pixel location reflectance values for the corresponding bands were subtracted to produce four difference images. Areas of major reflectance differences are isolated by thresholding each of the difference images. The resulting images are combined to obtain an image data set to total change. These areas of reflectance differences were found, in general, to correspond to areas of land cover change. Information on areas of land cover change was incorporated into a procedure to mask out all nonchange areas and perform an unsupervised classification only for data in the change areas. This procedure identified three broad categories: (1) areas of high reflectance (construction or extractive), (2) changes in agricultural areas, and (3) areas of confusion between agricultural and other areas.

Stauffer, M. L.↗
NASA NTRS1986

The March 1985 demonstration of the fiducial network concept for GPS geodesy: A preliminary report

The first field tests in preparation for the NASA Global Positioning System (GPS) Caribbean Initiative were conducted in late March and Early April of 1985. The GPS receivers were located at the POLARIS Very Long Base Interferometry (VLBI) stations at Westford, Massachusetts; Richmond, Florida; and Ft. Davis, Texas; and at the Mojave, Owens Valley, and Hat Creek VLBI stations in California. Other mobile receivers were placed near Mammoth Lakes, California; Pt. Mugu, California; Austin, Texas; and Dahlgren, Virginia. These sites were equipped with a combination of GPS receiver types, including SERIES-X, TI-4100 and AFGL dual frequency receivers. The principal objectives of these tests were the demonstration of the fiducial network concept for precise GPS geodesy, the performance assessment of the participating GPS receiver types, and to conduct the first in a series of experiments to monitor ground deformation in the Mammoth Lakes-Long Valley caldera region in California. Other objectives included the testing of the water vapor radiometers for the calibration of GPS data, the development of efficient procedures for planning and coordinating GPS field exercise, the establishment of institutional interfaces for future cooperating ventures, the testing of the GPS Data Analysis Software (GIPSY, for GPS Inferred Positioning SYstem), and the establishment of a set of calibration baselines in California. Preliminary reports of the success of the field tests, including receiver performance and data quality, and on the status of the data analysis software are given.

Davidson, J. M.↗
NASA NTRS1985

Emission by OD in comets

A calculation has been made of the complete fluorescent equilibrium of OD in sunlight including ultraviolet (A-X) transitions, vibrational and rotational transitions (A-A and X-X), and Lambda-doubling transitions in the X state. The dependence on heliocentric radial velocity is strong. No lines of OD are visible in any cometary spectra taken with IUE, but the limits vary, considerably from one comet to another. In the most favorable case, comet Austin 1982 VI, the limit is OD/OH less than 0.004. Optimum conditions for detecting OD in comet Halley are also discussed.

Ahearn, M. F.↗
NASA NTRS1987

Extraterrestrial infrastructure design projects

This paper is a synopsis of the mission planning and space design activities at The University of Texas at Austin during the 1985-86 calendar years. The research described has been conducted on both the undergraduate and graduate level and is continuing. The primary emphasis of the undergraduate program has focused on a manned Mars mission. The graduate research has concentrated on a lunar base; specifically, the feasibility of an electromagnetic lunar launcher and the development of a parametric lunar base computer simulation.

Bilby, Curt↗
NASA NTRS1988

The addition of visible channel data to satellite infrared rain estimation schemes

The effect of adding visible channel (VIS) data to the IR data in satellite rain estimation schemes was investigated by comparing the abilities of satellite threshold schemes based on VIS, IR channel, or bispectral (VIS/IR) data to estimate convective precipitation. Using the methodology of Bellon and Austin (1986), empirical relationships between the satellite and radar data were determined for two areas: the Florida Area Cumulus Experiment (FACE) area and a 25-km area on a side centered on 26 N, 81 W, which was inclusive of the FACE area but exclusive of points within 50 km or greater than 170 km of the Miami WSR-57 radar. The results did not demonstrate an unequivocal effect of VIS data. The normalized rms error data for the three estimation schemes used in a four-day experiment are presented.

Negri, Andrew J.↗
NASA NTRS1988

Space Station Freedom - A resource for aerospace education

The role of the International Space Station in future U.S. aerospace education efforts is discussed from a NASA perspective. The overall design concept and scientific and technological goals of the Space Station are reviewed, and particular attention is given to education projects such as the Davis Planetarium Student Space Station, the Starship McCullough, the Space Habitat, the working Space Station model in Austin, TX, the Challenger Center for Space Life Education, Space M+A+X, and the Space Science Student Involvement Program. Also examined are learning-theory aspects of aerospace education: child vs adult learners, educational objectives, teaching methods, and instructional materials.

Brown, Robert W.↗
NASA NTRS1990

An investigation into the numerical prediction of boundary layer transition using the K.Y. Chien turbulence model

Assessments were made of the simulation capabilities of transition models developed at the University of Minnesota, as applied to the Launder-Sharma and Lam-Bremhorst two-equation turbulence models, and at The University of Texas at Austin, as applied to the K. Y. Chien two-equation turbulence model. A major shortcoming in the use of the basic K. Y. Chien turbulence model for low-Reynolds number flows was identified. The problem with the Chien model involved premature start of natural transition and a damped response as the simulation moved to fully turbulent flow at the end of transition. This is in contrast to the other two-equation turbulence models at comparable freestream turbulence conditions. The damping of the transition response of the Chien turbulence model leads to an inaccurate estimate of the start and end of transition for freestream turbulence levels greater than 1.0 percent and to difficulty in calculating proper model constants for the transition model.

Stephens, Craig A.↗
NASA NTRS1989

Modularity in robotic systems

Most robotic systems today are designed one at a time, at a high cost of time and money. This wasteful approach has been necessary because the industry has not established a foundation for the continued evolution of intelligent machines. The next generation of robots will have to be generic, versatile machines capable of absorbing new technology rapidly and economically. This approach is demonstrated in the success of the personal computer, which can be upgraded or expanded with new software and hardware at virtually every level. Modularity is perceived as a major opportunity to reduce the 6 to 7 year design cycle time now required for new robotic manipulators, greatly increasing the breadth and speed of diffusion of robotic systems in manufacturing. Modularity and its crucial role in the next generation of intelligent machines are the focus of interest. The main advantages that modularity provides are examined; types of modules needed to create a generic robot are discussed. Structural modules designed by the robotics group at the University of Texas at Austin are examined to demonstrate the advantages of modular design.

Tesar, Delbert↗
NASA NTRS1990

Workshop on Observations of Recent Comets (1990)

Potential interpretations are presented for observations of four comets: Brorsen-Metcalf (1989o), Okazaki-Levy-Rudenko (1989r), Aarseth-Brewington (1989a1), and Austin (1989o1). The relationship of minor species with each other and possible parents as well as with dust are being pursued in a number of investigations. Of particular interest are the abundance ratios of CH4 to CO and NH3 to N2. The need for closer collaboration betwen observing teams and modelers is examined. The need for dust size distribution as a function of cometocentric distance to be analyzed in closer collaboration between observers and modelers is discussed.

Huebner, Walter F.↗