An Overview of LightSAR; A Proposed Radar Satellite


James W. Schoonmaker, Jr., USGS


The use of radar to map temperate glaciers and monitor their changing conditions has some advantages over traditional aerial photographs (Schoonmaker et al., 1989). Radar, being an active sensor in the microwave part of the electromagnetic spectrum, is capable of day or night imaging in almost all weather conditions. Radar, especially synthetic aperture radar (SAR), can also be used as a complementary data source with photography and multispectral imagery (Montgomery, 1996).

In August 1996, the National Aeronautics and Space Administration (NASA) held a workshop at the EROS Data Center (EDC), Sioux Falls, SD, on a proposed synthetic aperture radar satellite designed by the Jet Propulsion Laboratory (JPL) and dubbed LightSAR. Due to the possible applicability of LightSAR data to glaciology, a brief overview of the system was presented. Briefing materials were obtained from JPL's handout (Anon., 1996).

LightSAR as proposed will build upon experience gained from previous radar satellites: Seasat, ERS-1, JERS-1, SIR-C, and Radarsat. It will be low cost with a planned launch in September 1999 for a 3 year mission. The payload will be L-band synthetic aperture radar, multi-resolution/swath, multi-polarization, repeat path interferometry (stereo). Resolution will vary with swath; from spotlight (3 m, 15x20 km) to broad scan (100 m, 280 km). Orbit characteristics are: sun synchronous, near polar, 600 km, 10 day repeat cycle, with near global coverage (small gap around poles only).


Anonymous, 1996, LightSAR preliminary phase A study, Jet Propulsion Laboratory: Applications of Future US Spaceborne Imaging Radar Missions Workshop, Sioux Falls, SD, Aug. 27-29, 1996.

Montgomery, D.R., ed., 1996, Operational use of civil space-based synthetic aperture radar (SAR): JPL Publication 96-16, Pasadena, CA, p. 9-1.

Schoonmaker, J.W., Jr., Jones, J.E., and Molnia, B.F., 1989, Preliminary results of glacier studies from digital radar data: ASPRS/ACSM Annual Convention, Remote Sensing, Agenda for the 90's, Baltimore, MD, 1989, Technical Papers, v. 3, p. 1-9.

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