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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.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Demonstration of the fiducial concept using data from the March 1985 GPS field test

The first field test of NASA's Global Positioning System (GPS) Geodetic Program took place in March of 1985. The principal objective of this test was the demonstration of the feasibility of the fiducial station approach to precise GPS-based geodesy and orbit determination. Other objectives included an assessment of the performance of the several GPS receiver types involved in these field tests and the testing of the GIPSY software for GPS data analysis. In this article, the GIPSY (GPS Inferred Positioning System) software system is described and baseline solutions are examined for consistency with independent measurements made using very long baseline interferometry.

Davidson, J. M.↗
NASA NTRS1974

Optical cross beam field tests at ESSA Haswell Field site, October 1969

A series of tests with both the visible and IR optical cross beam systems was made at the Haswell, Colorado, Field Site of ESSA. This memorandum covers only the details of the test setup and runs. A joint field test program was undertaken by ESSA at a 164 meter (500 foot) meteorological tower. The tower was instrumented with wind sensors, temperature sensors, temperature sensors, fluctuating wind and temperature sensors and humidity sensors. The sensors were located at three elevations: 42, 192 and 162 meters. A movable elevator was also instrumented and could be positioned at any desired location along the tower height. The main object of the cross beam studies was to compare the visible and IR systems. The instruments were also arranged so that direct comparison with the sensors on the tower can be made.

Sandborn, V. A.↗
NASA NTRS1986

Objectives and first results of the NASA SETI sky survey field tests at Goldstone

Field tests of SETI (Search for Extraterrestrial Intelligence) prototype hardware and software began in March 1985 at Goldstone. With emphasis on the sky survey component of the NASA SETI search strategy, the article describes the survey characteristics, the detection strategy, and preliminary results of system tests.

Gulkis, S.↗
NASA NTRS1988

Mobilestar field test program

Various field tests were performed in order to gain practical experience and a broader understanding of mobile communications. The first phase consisted of CW propagation tests to develop firsthand experience of propagation phenomena. From this information, estimates of the feasibility and accuracy of power control were possible. The next phase tested the idea of power control. Equipment representative of that expected to be used in an actual mobile satellite communication system was assembled and tested under a variety of environments.

Rubow, Wayne↗
NASA NTRS1985

Photovoltaic-Powered Vaccine Refrigerator: Freezer Systems Field Test Results

A project to develop and field test photovoltaic-powered refrigerator/freezers suitable for vaccine storage was undertaken. Three refrigerator/freezers were qualified; one by Solar Power Corp. and two by Solvolt. Follow-on contracts were awarded for 19 field test systems and for 10 field test systems. A total of 29 systems were installed in 24 countries between October 1981 and October 1984. The project, systems descriptions, installation experiences, performance data for the 22 systems for which field test data was reported, an operational reliability summary, and recommendations relative to system designs and future use of such systems are explained. Performance data indicate that the systems are highly reliable and are capable of maintaining proper vaccine storage temperatures in a wide range of climatological and user environments.

Ratajczak, A. F.↗
NASA NTRS1985

Objectives and first results of the NASA SETI Sky Survey field tests at Goldstone, California

The objectives and preliminary results of the initial field tests of the prototype hardware and software for the NASA SETI program are reviewed with emphasis on the Sky Survey component of the NASA search strategy. In particular, attention is given to field test instrumentation, sky pixelation, sky survey field tests, baseline tests, antenna control tests, and radio frequency interference survey. The test results and observational experience will be used to finalize the design of the SETI Sky Survey processing system and to optimize the observational strategy and procedures in time to begin a full-scale Microwave Observing Program in 1990.

Gulkis, S.↗
NASA NTRS1965

Magnetic field test coils are temperature compensated

Magnetic field test coils with auxiliary winding wound opposite to main coil winding eliminates changes in field configurations due to temperature changes. The auxiliary coil is made with aluminum wire.

Source record↗
NASA NTRS1987

Antarctic field tests of SARSAT personal locater beacons

Field tests of SARSAT personal locater beacons were conducted in the Antarctic to assess the viability of using these beacons to increase the safety of Antarctic field parties. Data were collected on the extent to which dry or wet snow, melting conditions, crevasse walls and snow bridges affected the ability of the SARSAT satellite to calculate an accurate position of the beacon. Average response time between beacon turn on and alert reception in McMurdo was between 4 and 5 hours for these tests. It is concluded that the SARSAT system is viable for Antarctic operations and it is recommended that it be implemented for future field operations. Because of obstruction of line-of-sight between beacon and satellite degrades the accuracy of the location calculation (particularly in wet snow), it is further recommended that field parties have sufficient numbers of beacons to insure that in an emergency, one will be able to operate from the surface.

Bindschadler, Robert↗
NASA NTRS1985

Onsite 40-kilowatt fuel cell power plant manufacturing and field test program

A joint Gas Research Institute and U.S. Department of Energy Program was initiated in 1982 to evaluate the use of fuel cell power systems for on-site energy service. Forty-six 40 kW fuel cell power plants were manufactured at the United Technologies Corporation facility in South Windsor, Connecticut, and are being delivered to host utilities and other program participants in the United States and Japan for field testing. The construction of the 46 fully-integrated power plants was completed in January 1985 within the constraints of the contract plan. The program has provided significant experience in the manufacture, acceptance testing, deployment, and support of on-site fuel cell systems. Initial field test results also show that these experimental power plants meet the performance and environmental requirements of a commercial specification. This Interim Report encompasses the design and manufacturing phases of the 40 kW Power Plant Manufacturing and Field Test program. The contract between UTC and NASA also provides UTC field engineering support to the host utilities, training programs and associated manuals for utility operating and maintenance personnel, spare parts support for a defined test period, and testing at UTC of a power plant made available from a preceding program phase. These activities are ongoing and will be reported subsequently.

Source record↗
NASA NTRS1983

Field test experience

As a part of the Flat-Plate Solar Array Project (FSA), a field-test program was developed to obtain solar photovoltaic (PV) module performance and endurance data. These data are used to identify the specific characteristics of module designs under various environmental conditions. The information obtained from field testing is useful to all participants in the National Photovoltaics Program, from the research planner to the life-cycle cost analyst.

Weaver, R. W.↗
NASA NTRS1979

LSA field test

Degradation tests indicate that electrical degradation is not a slow monotonically increasing phenomenon as originally thought but occurs abruptly as the result of some traumatic event. This finding has led to a change in the test philosophy. A discussion of this change is presented along with a summary of degradation and failure data from all the sites and results from a variety of special tests. New instrumentation for in-field measurements are described. Field testing activity was expanded by the addition of twelve remote sites located as far away as Alaska and the Canal Zone. Descriptions of the new sites are included.

Jaffe, P.↗
NASA NTRS1986

Near-field testing of the 30 GHz TRW proof-of-concept multibeam antenna

Near-field testing was conducted on the 30 GHz TRW proof-of-concept (POC) Multibeam Antenna (MBA). The TRW POC MBA is a dual offset Cassegrain reflector system using a 2.7 m main reflector. This configuration was selected to assess the ability to create both multiple fixed and scanned spot beams. The POC configuration investigated frequency reuse via spatial separation of beams, polarization selectivity and time division multiple access scanning at 30 GHz. Measurements of directivity, sidelobe level, and pattern were made at NASA Lewis Research Center's Near-Field Antenna Test Facility. Presented in this paper are complete results of these measurements. Included is a detailed discussion of all testing procedures and parameters. Results of additional testing used to evaluate diffraction effects of the subreflector and distortions of the main reflector are also presented.

Kunath, R. R., Jr.↗
NASA NTRS1986

Near-field testing of the 15-meter model of the hoop column antenna. Volume 3: Near- and far-field plots for the JPL feed

Technical results from near-field testing of the 15-meter model of the hoop column antenna at the Martin Marietta Denver Aerospace facility are discussed. The antenna consists of a deployable central column and a 15 meter hoop, stiffened by cables into a structure with a high tolerance repeatable surface and offset feed location. The surface has been configured to have four offset parabolic apertures, each about 6 meters in diameter, and is made of gold plated molybdenum wire mesh. Pattern measurements were made with feed system radiating at frequencies of 7.73, 11.60, 2.27, 2.225, and 4.26 (all in GHz). This report (Volume 3) gives the detailed patterns measured with the JPL feed (2.225 GHz). Volume 1 covers the testing from an overall viewpoint and contains information of generalized interest for testing large antennas, including the deployment of the antenna in the Martin Facility and the measurements to determine mechanical stability and trueness of the reflector surface, the test program outline, and a synopsis of antenna electromagnetic performance. A detailed listing of the antenna patterns for the LaRC feeds (7.3, 11.60, 2.27, and 4.26 GHz) are given in Volume 2 of this report.

Hoover, J.↗
NASA NTRS1986

Near-field testing of the 15-meter model of the hoop column antenna. Volume 2: Near- and far-field plots for the LaRC feeds

The technical results from near-field testing of the 15-meter model of the hoop column antenna at the Martin Marietta Denver Aerospace facility are described. The antenna consists of a deployable central column and a 15-meter hoop, stiffened by cable into a structure with a high tolerance repeatable surface and offset feed location. The surface has been configured to have four offset parabolic apertures, each about 6 meters in diameter, and is made of gold plated molybdenum wire mesh. Pattern measurements were made with feed systems radiating at frequencies of 7.73, 11.60, 2.27, 2.225, and 4.26 (all in GHz). This report (Volume II) gives the detailed patterns measured with the LaRC feeds (7.73, 11.60, 2.27, and 4.26 GHz). Volume I covers the testing from an overall viewpoint and contains information of generalized interest for testing large antennas, including the deployment of the antenna in the Martin Facility and the measurements to determine mechanical stability and trueness of the reflector surface, the test program outline, and a synopsis of antenna electromagnetic performance. A detailed listing of the antenna patterns are provided for the 2.225 Ghz feed in Volume III of this report.

Hoover, J.↗
NASA NTRS1986

Goldstone field test activities: Target search

In March of this year prototype SETI equipment was installed at DSS13, the 26 meter research and development antenna at NASA's Goldstone complex of satellite tracking dishes. The SETI equipment will remain at this site at least through the end of the summer so that the hardware and software developed for signal detection and recognition can be fully tested in a dynamic observatory environment. The field tests are expected to help understand which strategies for observing and which signal recognition algorithms perform best in the presence of strong man-made interfering signals (RFI) and natural astronomical sources.

Tarter, J.↗
NASA NTRS1987

Detecting forest structure and biomass with C-band multipolarization radar - Physical model and field tests

The ability of C-band radar (4.75 GHz) to discriminate features of forest structure, including biomass, is tested using a truck-mounted scatterometer for field tests on a 1.5-3.0 m pygmy forest of cypress (Cupressus pygmaea) and pine (Pinus contorta ssp, Bolanderi) near Mendocino, CA. In all, 31 structural variables of the forest are quantified at seven sites. Also measured was the backscatter from a life-sized physical model of the pygmy forest, composed of nine wooden trees with 'leafy branches' of sponge-wrapped dowels. This model enabled independent testing of the effects of stem, branch, and leafy branch biomass, branch angle, and moisture content on radar backscatter. Field results suggested that surface area of leaves played a greater role in leaf scattering properties than leaf biomass per se. Tree leaf area index was strongly correlated with vertically polarized power backscatter (r = 0.94; P less than 0.01). Field results suggested that the scattering role of leaf water is enhanced as leaf surface area per unit leaf mass increases; i.e., as the moist scattering surfaces become more dispersed. Fog condensate caused a measurable rise in forest backscatter, both from surface and internal rises in water content. Tree branch mass per unit area was highly correlated with cross-polarized backscatter in the field (r = 0.93; P less than 0.01), a result also seen in the physical model.

Westman, Walter E.↗