THE SIR-C X-SAR SYNTHETIC-APERTURE RADAR SYSTEM/

The Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/ X-SAR) was a joint United States/German/Italian space agency imaging r adar system successfully flown aboard the shuttle Endeavor in April 19 94 and again in September/October 1994, The multifaceted SIR-C/X-SAR r epresents a major technological step forward in radar remote sensing a nd is the first spaceborne multifrequency, polarimetric SAR, The Unite d States developed SIR-C operated at L- and C-band, each with quad pol arization, The SIR-C antenna was an active phased array, with the capa bility for electronic beam steering and multiple swath width illuminat ion, The German/Italian X-SAR operated at X-band with a single polariz ation using a slotted waveguide antenna, mechanically steerable in ele vation, SIR-C and X-SAR were designed to operate synchronously, collec ting data over common sites synchronously, A total of 143 hours (93 te rabits) of SAR data were recorded on tape.