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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

LSA field test

After almost four years of endurance testing of photovoltaic modules, no fundamental life-limiting mechanisms were identified that could prevent the twenty-year life goal from being met. The endure data show a continual decline in the failure rate with each new large-scale procurement. Cracked cells and broken interconnects continue to be the principal causes of failure. Although the modules are more adversely affected physically by hot, humid environments than by cool or dry environments there are insufficient data to correlate failure with environment. There is little connection between the outward physical condition of a module and changes in its electrical performance.

Jaffe, P.↗
NASA NTRS1981

Design, development, and field testing of Infrared Heterodyne Radiometer (IHR) for remote profiling of tropospheric and stratospheric species

The performance of a dual-channel infrared heterodyne radiometer, designed to remotely monitor the concentration and vertical distribution of selected atmospheric species, is described. Ground based solar viewing measurement using the IHR were performed at selected laser transitions for ammonia (NH3 and ozone O3). Flight tests were conducted aboard the Galileo II, NASA Ames CV-990, on the Latitude Survey Mission. Ozone was the selected atmospheric species for the airborne flight measurements because of the scientific interest in this atmospheric species, the availability of in situ monitors, the coordinated ozone measurements, and the availability of ground truth data. The IHS was operated in the solar viewing mode to determine ozone distributions in the stratosphere and in the nadir viewing mode to determine the ozone distribution in the troposphere. Airborne atmospheric propagation measurements also were carried out at selected CO2 laser transitions.

Lange, R.↗
NASA NTRS1980

The 40-kw field test power plant modification and development, phase 2

Progression on the design and development of a 40 KW fuel cell system for on-site installation for providing both thermal and electrical power is reported. Development of the steam reformer fuel processor, power section, inverter, control system, and thermal management and water treatment systems is described.

Source record↗
NASA NTRS1981

Laser induced fluoroescence from algae: Results of a ship-borne field test

A basis is provided for the feasibility of air-borne laser fluorosensing not only of chlorophyll but also of pollutants such as oils and chemicals. There was a satisfactory correlation between the laser data and those obtained manually. The absolute determination of the chlorophyll concentration is discussed.

Hartmann, B.↗
NASA NTRS1981

Applications systems verification and transfer project. Volume 4: Operational applications of satellite snow cover observations. Colorado Field Test Center

The study was conducted on six watersheds ranging in size from 277 km to 3460 km in the Rio Grande and Arkansas River basins of southwestern Colorado. Six years of satellite data in the period 1973-78 were analyzed and snowcover maps prepared for all available image dates. Seven snowmapping techniques were explored; the photointerpretative method was selected as the most accurate. Three schemes to forecast snowmelt runoff employing satellite snowcover observations were investigated. They included a conceptual hydrologic model, a statistical model, and a graphical method. A reduction of 10% in the current average forecast error is estimated when snowcover data in snowmelt runoff forecasting is shown to be extremely promising. Inability to obtain repetitive coverage due to the 18 day cycle of LANDSAT, the occurrence of cloud cover and slow image delivery are obstacles to the immediate implementation of satellite derived snowcover in operational streamflow forecasting programs.

Shafer, B. A.↗
NASA NTRS1981

FSA field test

The 12 continental remote sites were decommissioned. Testing was consolidated into a five-site network consisting of the four Southern California sites and a new Florida site. 16 kW of new state-of-the-art modules were deployed at the five sites. Testing of the old modules continued at the Goldstone site but as a low-priority item. Array testing of modules is considered. Additional new testing capabilities were added. A battery-powered array data logger is discussed. A final set of failure and degradation data was obtained from the modules.

Jaffe, P.↗
NASA NTRS1983

FSA field test report, 1980 - 1982

Photovoltaic modules made of new and developing materials were tested in a continuing study of weatherability, compatibility, and corrosion protection. Over a two-year period, 365 two-cell submodules have been exposed for various intervals at three outdoor sites in Southern California or subjected to laboratory acceptance tests. Results to date show little loss of maximum power output, except in two types of modules. In the first of these, failure is due to cell fracture from the stresses that arise as water is regained from the surrounding air by a hardboard substrate, which shrank as it dried during its encapsulation in plastic film at 150 C in vacuo. In the second, the glass superstrate is sensitive to cracking, which also damages the cells electrostatically bonded to it; inadequate bonding of interconnects to the cells is also a problem in these modules. In a third type of module, a polyurethane pottant has begun to yellow, though as yet without significant effect on maximum power output.

Maxwell, H. G.↗
NASA NTRS1984

Field tests of the real-data acquisiton system for the NASA-LaRC differential absorption lidar

A data acquisition system (DAS) for the NASA/LaRC Differential Absorption Lidar (DIAL) was documented. This DAS is a dual LSI 11/23 set up where one computer retrieves data from the digitizers and other peripheral units, stores that data on magnetic tape, generates aerosol grayscales on a Trilog printer and passes data to the second computer. The second computer is dedicated to real time displays of the data in a variety of modes from raw data to range resolved ozone profiles. The DIAL DAS also has several new features.

Butler, C.↗
NASA NTRS1984

Status of DOE and AID stand-alone photovoltaic system field tests

The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

Bifano, W. J.↗
NASA NTRS1975

Studies related to ocean dynamics. Task 3.2: Aircraft Field Test Program to investigate the ability of remote sensing methods to measure current/wind-wave interactions

The feasibility of remote sensing of current flows in the ocean and the remote sensing of ocean currents by backscattering cross section techniques was studied. It was established that for capillary waves, small scale currents could be accurately measured through observation of wave kinematics. Drastic modifications of waves by changing currents were noted. The development of new methods for the measurement of capillary waves are discussed. Improvement methods to resolve data processing problems are suggested.

Huang, N. E.↗
NASA NTRS1986

Goldstone field test activities: Sky survey

The goals are to conduct a research and development program aimed at determining the most effective way to do SETI within the constraints of current technology and estimated budgets. The general search strategy adopted is that which is recommended by the SETI Science Working Group. The strategy for an all sky survey for SETI was further developed over the last year. Scan patterns, scan rates, and signal detection algorithms were developed. Spectral power measurement instrumentation was tested at the Venus Station of the Goldstone Deep Space Communication Complex. A specially designed radio frequency interference (RFI) measurement system was built and installed at the Venus Station. A data base management system for storage and retrieval of the RFI data was partially implemented on a VAX 750 computer at the Jet Propulsion Laboratory.

Gulkis, S.↗
NASA NTRS1986

Precise GPS orbit determination results from 1985 field tests

Data from three different receiver types have been used to obtain precise orbits for the satellites of the Global Positioning System (GPS). The data were collected during the 1985 March-April GPS experiment to test and validate GPS techniques for precision orbit determination and geodesy. A new software package developed at the Jet Propulsion Laboratory (JPL), GIPSY (GPS Inferred Positioning SYstem), was used to process the data. To assess orbit accuracy, solutions are compared using integrated doppler data from various different receiver types, different fiducial sites, and independent data arcs, including one spanning six days. From these intercomparisons, orbit accuracy for a well-tracked GPS satellite of three meters in altitude and about five meters in each of down and cross-track components are inferred.

Lichten, S. M.↗
NASA NTRS1987

Field test to intercompare carbon monoxide, nitric oxide and hydroxyl instrumentation at Wallops Island, Virginia

Documentation of the first of three instrument intercomparisons conducted as part of NASA Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation (GTE/CITE-1) is given. This ground-based intercomparison was conducted during July 1983 at NASA Wallops Flight Facility. Instruments intercompared included one laser system and three grab-sample approaches for CO; two chemiluminescent systems and one laser-induced fluorescent (LIF) technique for NO; and two different LIF systems and a radiochemical tracer technique for OH. The major objectives of this intercomparison was to intercompare ambient measurements of CO, NO, and OH at a common site by using techniques of fundamentally different detection principles and to identify any major biases among the techniques prior to intercomparison on an aircraft platform. Included in the report are comprehensive discussions of workshop requirements, philosophies, and operations as well as intercomparison analyses and results. In addition, the large body of nonintercomparison data incorporated into the workshop measurements is summarized. The report is an important source document for those interested in conducting similar large and complex intercomparison tests as well as those interested in using the data base for purposes other than instrument intercomparison.

Gregory, Gerald L.↗
NASA NTRS1986

Narrowband signal detection in the SETI field test

Various methods for detecting narrow-band signals are evaluated. The characteristics of synchronized and unsynchronized pulses are examined. Synchronous, square law, regular pulse, and the general form detections are discussed. The CW, single pulse, synchronous, and four pulse detections are analyzed in terms of false alarm rate and threshold relative to average noise power. Techniques for saving memory and retaining sensitivity are described. Consideration is given to nondrifting CW detection, asynchronous pulse detection, interpolative and extrapolative pulse detectors, and finite and infinite pulses.

Cullers, D. Kent↗