The Shuttle Imaging Radar—C(SIR---C) is a synthetic aperture radar(SAR) designed to fly on the Space Shuttle as a payload instrument in the Shuttle Radar Laboratory(SRL). To fly together with SIR-C are the German/Italian X-band SAR(X-SAR) and the Data Processing Subsystem (DPS), built by the Applied Physics Laboratory of John Hopkins University. The first mission is scheduled in mid-April, 1994, for an 8-day duration, with one follow-up mission in planning. The instrument itself — its inheritance, mission profile, potential scientific advances, design and performance — has been published earlier"2