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 radar system successfully flown aboard the shuttle Endeavor in April 1994 and again in September/October 1994. The multifaceted SIR-C/X-SAR represents a major technological step forward in radar remote sensing and is the first spaceborne multifrequency, polarimetric SAR. The United States developed SIR-C operated at L- and C-band, each with quad polarization. The SIR-C antenna was an active phased array, with the capability for electronic beam steering and multiple swath width illumination. The German/Italian X-SAR operated at X-band with a single polarization using a slotted waveguide antenna, mechanically steerable in elevation. SIR-C and X-SAR were designed to operate synchronously, collecting data over common sites synchronously. A total of 143 hours (93 terabits) of SAR data were recorded on tape.>