Search NASA⌕ Search

SEARCH · Search NASA

Results for “spaceborne radar”

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
NASA NTRS1982

Geological mapping from spaceborne imaging radars Kentucky-Virginia, USA

Radar images (at wavelength 23.5 cm) of a 50-km-wide swath across Kentucky and Virginia obtained with the Shuttle Imaging Radar experiment (SIR-A) in 1981 and with the Seasat SAR in 1978 are compared. Image tone and texture, lineament mapping, drainage mapping, and the effects of illumination geometry and incidence angle are considered, and sample Landsat images are evaluated. The dominant backscatter effect in the SIR-A images is found to facilitate the mapping of steeply sloping terranes and lineaments shorter than the Seasat length resolution limit of about 15 km. It is determined that optimum enhancement of topographic features is obtained when the radar look angle exceeds the surface slope angle by a discrete amount, avoiding layover or relief displacement. A variable-look-angle radar is needed to maintain low incidence angles in regions with widely varying slope angles, as illustrated by the Landsat MSS images.

Ford, J. P.↗
NASA NTRS1985

Use of spaceborne imaging radar in regional geomorphic studies

In the past two decades, the use of both photographic and non-photographic remote sensing from satellite platforms has provided a unique capability for the observation and study of Earth and planetary surfaces. A wide range of imaging sensors that operate in different portions of the electromagnetic spectrum have yielded images of large areas that formerly were unknown or that had not previously been observed at a simultaneous instant in time. In addition, remote sensors equipped with multispectral or multiband capabilities are capable of taking data at different wavelengths simultaneously. Notable examples include the LANDSAT series of multispectral scanners, thematic mappers, and return beam vidicons. Synthetic aperture radar and LANDSAT imagery are discussed.

Ford, J. P.↗
NASA NTRS1985

Spaceborne Imaging Radar (SIR) project

An overview is given of elements of the SIR (Shuttle Imaging Radar) project, covering the coming decade. The project is intended to develop the scientific basis and the required technology of the Earth Orbiting Satellite (EOS) Synthetic Aperture Radar (SAR). Plans are ongoing for a SIR-B reflight in 1987, a dual SIR-C flight in 1989 and a SIR-D flight in 1992 leading to an advanced multispectral multipolarization imaging sensor for flight on EOS in 1994. The conventional and distributed radar approaches are compared.

Elachi, C.↗
NASA NTRS1987

Spaceborne imaging radar on EOS

A multiparameter synthetic aperture imaging radar is planned as a facility instrument for the Earth Orbiting System (EOS). This sensor will operate at L, C, and X and at all possible polarizations (HH, VV, HV, VH), thus allowing the acquisition of detailed information about the surface physical and electrical properties. When combined with the visible and IR imaging spectrometry data and the surface topography, a full description of the surface structure, composition, thermal properties and physical properties could then be extracted.

Elachi, Charles↗
NASA NTRS1987

The Spaceborne Imaging Radar program: SIR-C - The next step toward EOS

The NASA Shuttle Imaging Radar SIR-C experiments will investigate earth surface and environment phenomena to deepen understanding of terra firma, biosphere, hydrosphere, cryosphere, and atmosphere components of the earth system, capitalizing on the observational capabilities of orbiting multiparameter radar sensors alone or in combination with other sensors. The SIR-C sensor encompasses an antenna array, an exciter, receivers, a data-handling network, and the ground SAR processor. It will be possible to steer the antenna beam electronically, so that the radar look angle can be varied.

Evans, Diane↗
NASA NTRS1988

Assessment of forest cover changes using multidate spaceborne imaging radar

Data obtained in 1978 by Seasat and in 1984 by SIR-B over a forested area in northern Florida are analyzed. The objective of the study was to determine the potential for detecting major changes in forest cover utilizing synthetic aperture radar obtained from satellite altitudes, and to define an effective methodology for processing and analyzing digital synthetic aperture radar data obtained on two different dates. It is found that multitemporal synthetic aperture radar data obtained from satellite altitudes can be used to detect major changes in forest cover conditions such as deforestation and reforestation. A suprisingly good level of detectivity was obtained for identifying areas of regrowth after they had been clearcut and replanted.

Lee, Kyu-Sung↗
NASA NTRS1996

Geomorphic Processes and Remote Sensing Signatures of Alluvial Fans in the Kun Lun Mountains, China

The timing of alluvial deposition in arid and semiarid areas is tied to land-surface instability caused by regional climate changes. The distribution pattern of dated deposits provides maps of regional land-surface response to past climate change. Sensitivity to differences in surface roughness and composition makes remote sensing techniques useful for regional mapping of alluvial deposits. Radar images from the Spaceborne Radar Laboratory and visible wavelength images from the French SPOT satellite were used to determine remote sensing signatures of alluvial fan units for an area in the Kun Lun Mountains of northwestern China. These data were combined with field observations to compare surface processes and their effects on remote sensing signatures in northwestern China and the southwestern United States. Geomorphic processes affecting alluvial fans in the two areas include aeolian deposition, desert varnish, and fluvial dissection. However, salt weathering is a much more important process in the Kun Lun than in the southwestern United States. This slows the formation of desert varnish and prevents desert pavement from forming. Thus the Kun Lun signatures are characteristic of the dominance of salt weathering, while signatures from the southwestern United States are characteristic of the dominance of desert varnish and pavement processes. Remote sensing signatures are consistent enough in these two regions to be used for mapping fan units over large areas.

Farr, Tom G.↗
NASA NTRS2002

The next generation of spaceborne rain radars: science rationales and technology status

The 13.8 GHz Precipitation Radar (PR) aboard the US/Japan Tropical Rainfall Measuring Mission (TRMM) satellite is the first rain profiling radar ever launched into space. A TRMM follow-on mission, called the Global Precipitation Mission (GPM), is currently planned to extend and improve the TRMM acquired rainfall data set.

precipitation radar TRMM GPM↗
NASA NTRS2000

NASA/JPL Spaceborne Imaging Radar

A database for Earth is now being created as the result of the Shuttle Radar Topography Mission (SRTM) during a 11 day Shuttle Endeavour flight in February.

Radar Imaging SRTM Interferometric SAR History↗