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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Development of satellite position location system for aircraft and boat distress beacons

An international satellite system for the detection and location of distress beacons carried on aircraft and vessels is in its technical checkout phase. User demonstration and evaluation (D&E) will start in early 1983 and continue for two years. The D&E phase and a subsequent transition period will form the basis for improved search and rescue operations for the 1980's and beyond. The system, called COSPAS/SARSAT, has international participation involving the U.S., Canada, and France as SARSAT members and joint participation with the Soviet Union's COSPAS Project. Norway and the U.K. have recently joined as investigators. Average position location error of the satellite aided processing is expected to be from 10-20KM for the existing 121.5/243 MHz distress beacons and from 2-5KM for experimental beacons transmitting in the 406 MHz band.

Kahle, D. R.↗
NASA NTRS1984

SARSAT - Using space for the search and rescue of lives in distress

A major cooperative effort between west and east bloc nations in developing a new space system for detecting ships and aircraft in distress is discussed. The compatible working of the SARSAT system developed by Canada, France, and the US and the COSPAS system developed by the Soviet bloc is summarized, and the SARSAT system is described. The method of location determination is presented, and the ELT and EPIRB, space segment, local user terminal, and mission control center subsystems of the SARSAT system are surveyed, showing block diagrams and data on spacecraft orbital parameters and ELT/EPIRB BECON characteristics. The current problem of ground-based interference is discussed. An outline of future development activities leading to the implementation of a fully operational system is included.

Flatow, F.↗
NASA NTRS1984

A new wave of communication satellites

Satellites provide at present telephone, television, data, and business services on a national, regional, and international scale, and the geostationary arc has become crowded at C-band (6/4 GHz) and Ku-band (14/11 GHz) frequencies. The evolution and the present state of satellite communications are discussed along with details regarding the development of direct broadcast satellites, the position of Canada with respect to satellite communications, Japanese developments, ESA and Eutelsat, aspects of collaboration between France and Germany regarding communications satellites, the United Kingdom, and the Nordic countries.

Lovell, R. R.↗
NASA NTRS1984

Non-US approaches to space commercialization

The approaches to the commercialization of space taken by the four foreign countries most active in the field - Canada, France, the Federal Republic of Germany, and Japan are described. National space program elements with commercial potential are examined in the context of national industrial and science policies, with special attention to objectives, timetables, and budgetary priority relative to other sectors. The role of the European Space Agency in attaining national and regional commercialization objectives is also examined.

Smith, P. G.↗
NASA NTRS1984

Results of S5 CH tests with an ARL (Aerospace Research Laboratory) cascade

As part of a research agreement between Iowa State University of Science and Technology (ISU) and ONERA, a blade cascade designed and already tested in the United States was manufactured and tested in France. The ONERA cascade wind tunnel and mock-up are described. Attention is focused on defining the upstream conditions of the cascade. Experimental results are presented, as well as comparisons with tests conducted by Detroit Diesel Allison (DDA) in the United States.

Fourmaux, A.↗
NASA NTRS1985

A method for estimating soil moisture availability

A method for estimating values of soil moisture based on measurements of infrared surface temperature is discussed. A central element in the method is a boundary layer model. Although it has been shown that soil moistures determined by this method using satellite measurements do correspond in a coarse fashion to the antecedent precipitation, the accuracy and exact physical interpretation (with respect to ground water amounts) are not well known. This area of ignorance, which currently impedes the practical application of the method to problems in hydrology, meteorology and agriculture, is largely due to the absence of corresponding surface measurements. Preliminary field measurements made over France have led to the development of a promising vegetation formulation (Taconet et al., 1985), which has been incorporated in the model. It is necessary, however, to test the vegetation component, and the entire method, over a wide variety of surface conditions and crop canopies.

Carlson, T. N.↗
NASA NTRS1985

Supersonic Cruise Technology

The history and status of supersonic cruise research is covered. The early research efforts of the National Advisory Committee for Aeronautics and efforts during the B-70 and SST phase are included. Technological progress made during the NASA Supersonic Cruise Research and Variable Cycle Engine programs are presented. While emphasis is on NASA's contributions to supersonic cruise research in the U.S., also noted are developments in England, France, and Russia. Written in nontechnical language, this book presents the most critical technology issues and research findings.

Mclean, F. Edward↗
NASA NTRS1984

Tropospheric gravity waves observed by three closely spaced ST radars

Clear-air radar experiments were carried out on the southern coast of France during the (ALPEX) Alpine experiment program vertically directed stratosphere-troposphere-radars were set up with spacings of about 5 to 6 km. The temporal and spectral characteristics of the vertical velocity fluctuations were examined. The horizontal and vertical properties of gravity waves in the lower atmosphere were analyzed. The techniques used and the first results from this wave study are described.

Carter, D. A.↗
NASA NTRS1985

The eclipse of Epsilon Aurigae visible spectroscopy and ultraviolet activity

The preliminary results of the study of several high resolution spectrograms (lambda 3500 - lambda 7000 A), obtained at the Haute Provence Observatory (OHP) in France, at different epochs before, during and after the eclipse are reported. Some of these spectrograms are compared with corresponding IUE high resolution observations, in order to study the effects of the intrinsic UV activity, towards the longer wavelengths.

Ferluga, S.↗
NASA NTRS1985

An overview of European space transportation systems

With the completion of the launch rocket series Ariane 1 to 4, Europe will have reached the same capacity to transport commercial payloads as the USA has with the Space Shuttle and the kick stages which are presently operative. The near term development of these capacities would require Europe to develop a larger launch rocket, Araine 5. Further motivations for this rocket are access to manned spaceflight, the development of an European space station, and the demand for shuttle technology. Shuttle technology is the subject of research being done in France on the winged re-entry vehicle Hermes. Operation of the European space station Columbus will require development of an interorbital transport system to facilitate traffic between the various segments of the space station. All European space transportation systems will have to match their quality to that of the other countries involve in space flight. All areas of development are marked not only by possible cooperation but also by increased competition because of increasing commercialization of space flight.

Lo, R. E.↗
NASA NTRS1985

Middle atmosphere (60-110 km) tidal oscillations at Saskatoon, Canada (52 deg N, 107 deg W) during 1983/84

Since mid-1978, the medium frequency (2.2 MHz; M.F.) radar at Saskatoon has run continuously, measuring winds by the spaced antenna method in the upper middle atmosphere. As there is so much dynamics activity during the years of MAP it seems very important to establish the features of the tidal field at Saskatoon during 1983 to 1984, and compare these with the climatology from the four years 1978 to 1979 and 1981 to 1982. Wind profiles with 60 to 110 km (80 to 110 km at night) with 3 km resolution are obtained every 5 minutes by means of a full-correlation analysis. Hourly means are formed and harmonic analysis applied to sets of data to obtain the mean winds and tidal oscillation amplitudes and phases. The zonal wind field at Saskatoon is structurally similar to CIRA-72; however, the wind eastward cell is weaker and much more structured, and the summer eastward cell above 85 km is also weaker. For the semidiurnal tide, a strong seasonal change exists, with larger amplitudes and shorter wavelengths, in winter-like months and the reverse in summer-like months. A summary of the tidal parameters at 90 km is given, where mean values from 1978 to 1982 are also shown. This seasonal variation of tides is a midlatitude climatology, as comparisons with Monpazier, France and Christchurch, New Zealand show very similar behavior, as does Durham; and requires antisymmetric tidal modes such as 2,3 and 2,5. Considering the diurnal tide, for most months centered on summer there are long wavelength modes, or superposition of several models. However, some winter months show a short wavelength mode. A summary of the 90 km characteristics is presented.

Manson, A. H.↗
NASA NTRS1985

Tropospheric gravity waves observed by three closely-spaced ST radars

During a 6 week period in 1982, 3 ST (Stratosphere-Troposphere) radars measured horizontal and vertical wavelengths of small scale tropospheric gravity waves. These 50 MHz, vertically-directed radars were located in a trianglar network with approximately 5 km spacing on the southern coast of France at the mouth of the Rhone River during the ALPEX (Alpine Experiment) program.

Carter, D. A.↗
NASA NTRS1986

The Venus Balloon Project

On June 11 and 15, 1985, two instrumental balloons were released from the Soviet VEGA 1 and VEGA 2 spacecraft and deployed in the atmosphere of Venus. The VEGA probes flew by the planet on their way to a rendezvous with comet Halley in March 1986. Drifting with the wind at altitudes of 54 km, the balloons traveled one-third of the way around the planet during their 46-hour lifetimes. Sensors on-board the gondolas made periodic measurements of pressure, temperature, vertical wind velocity, cloud particle density, ambient light level, and frequency of lightning. The data were transmitted to Earth and received at the Deep Space Network (DSN) 64-m stations and at several large antennas in the USSR. Approximately 95 percent of the telemetry data were successfully decoded at the DSN complexes and in the Soviet Union, and were provided to the international science team for analysis. Very Long Baseline Interferometry (VLBI) data were acquired by 20 radio observatories around the world for the purpose of monitoring the Venus winds. The DSN 64-m subnet was part of a 15-station VLBI network organized by the Centre National d'Etudes Spatiales (CNES) of France. In addition, five antennas of the Soviet network participated. VLBI data from the CNES network are currently being processed at the Jet Propulsion Laboratory.

Stelzried, C. T.↗
NASA NTRS1985

Topex - A spaceborne ocean observing system

The key to the ocean's influence on life is its general circulation. For the study of this circulation, geostrophic currents at the sea surface can be mapped from space with the aid of satellite altimeters, which measure the height of the sea surface and its variations in time and space. In view of the usefulness of satellite altimetry, the European Space Agency, Japan, France, and the United State have plans to launch Seasat-class altimeters. The similarity between the U.S. and the French programs and goals for satellite altimetry has led the respective agencies to study the possibility of combining NASA's Ocean Topography Experiment Topex with CNES's Poseidon Project. The objectives of the combined Topex/Poseidon mission involve an enhancement of the understanding of ocean dynamics on the basis of precise and accurate observations of the oceanic topography for a period of three years. The mission is to provide the foundation for a continuing program concerned with long-term observations of oceanic circulation.

Born, G. H.↗
NASA NTRS1985

A survey of cryogenic wind tunnels

Following the development of the cryogenic wind tunnel at the NASA Langley Research Center in 1972, a large number of cryogenic wind-tunnel projects have been undertaken at various research establishments around the world. The purpose of this paper is to describe some of the more significant of these projects. Described in this paper are cryogenic wind-tunnel projects in China (CARDC), England (College of Aeronautics at Cranfield, RAE-Bedford, and University of Southampton), 'Europe' (Pilot European Transonic Windtunnel at NAL-Amsterdam, and the European Transonic Windtunnel proposed for DFVLR-Koeln), France (ONERA-CERT), Germany (DFVLR-Koeln, and DFVLR-Goettingen), Japan (NAL, University of Tsukuba, and National Defense Academy), Sweden (Rollab), and the United States (Douglas Aircraft Co., University of Illinois at Urbana-Champaign, and NASA-Langley).

Kilgore, R. A.↗
NASA NTRS1985

Optical remote sensing of the earth

In the present assessment of the contributions of optical earth resources remote sensing in the 0.4-15.0 micron region, attention is given to underlying principles, applications to scientific disciplines such as geology, hydrology and oceanography, the recent development history of the requisite sensors, and sensor development trends. Development status characterizations are given for thematic mapping, modular optoelectronic multispectral scanning, the telescope/CCD 'SPOT' program of France, the thermal IR multispectral scanner for mineral signature identification, airborne imaging spectrometry, and the Advanced Visible and IR Imaging Spectrometer that is nearing deployment. Technology development trends and the capabilities they portend are projected.

Goetz, A. F. H.↗
NASA NTRS1986

Remote sensing of Spartina anglica biomass in five French salt marshes

The utilization of regression models to estimate Spartina anglica biomass in marshes is studied. Radiance data for five S. anglica plots located along the coast of Brittany, France at 48 deg 40 min N between 1 deg 30 min W- 4 deg 30 min W was collected with a hand-held radiometer. Biomass data is derived from the radiance data, and the radiance and biomass data are employed in the formulation of simple regression models. The models are applied to the radiance data from the other four marshes. It is observed that the models predicted the biomass for all four marshes, and for three of the four marshes the estimated leaf and live biomass are within 1-13 percent of the harvest values. The effects of slit and dead tissues on the radiance from the S. anglica canopies are analyzed. It is noted that simple regression models which correlate radiance data to S. Anglica biomass in one marsh can be applied to the accurate prediction of leaf and live S. anglica biomass in other marshes.

Gross, M. F.↗
NASA NTRS1984

Characteristics of the SIR-A system and images

Sample images obtained with the Shuttle Imaging Radar A (SIR-A) are presented, along with design and performance features of the SIR-A, Seasat and Landsat images of the same scenes for comparison purposes. The SIR-A functions at the L-band 25 cm at a frequency of 1278 GHz with a spectral bandwidth of 6 MHz. The images were taken at an angle of 47 deg and furnished a resolution of 40 m from an altitude of 259 km. The images covered a ground swath 50 km wide. The images are provided to assist in the development of effective techniques for interpreting radar imagery. The SIR-A instrument is a precursor of another imaging device which will be flown around Venus. The images provided include sections of France, Sardinia and Algeria.

Rebillard, PH.↗