First ENVISAT and ERS-2 Parasitic Bistatic Fixed Receiver SAR Images Processed with the Subaperture Range-Doppler Algorithm

Past and current SAR missions, such as SIR-C, ERS- 1/2, ENVISAT, SRTM, E-SAR, etc. had in common that the signal transmitter and the receiver were located at the same moving platform. New missions are being planned [1] based on the bistatic concept, where transmitter and receiver subsystems are located at different locations and thus may follow different trajectories. But before these missions become a reality, there are several experiments to be considered. One of them is the Parasitic Bistatic Fixed Receiver case, a novel and challenging configuration regarding hardware development and SAR processing techniques. This configuration will improve our experience in the bistatic field with cost effective measurements. In this paper, we will present the first images of the ongoing satellite bistatic campaign in our department. The images have been acquired with the specific hardware SABRINA (SAR bistatic fixed receiver for interferometric applications, fully developed at UPC) and processed with the Subaperture Range- Doppler Algorithm which will be explained in detail. We have been using ESA´s ENVISAT and ERS-2 C-band SAR satellites as opportunity transmitters and we have located the hardware prototype receiver at the roof of our department looking to the illuminated scene, a hill in front of the Campus. The mean bistatic angle is about 75deg, the capture window is only two seconds long and experiments have a period of 35 days due to the satellite revisiting time.