Preparatory Investigations Concerning the Calibration of Spaceborne Sar-Systems

P. Seifert, H.Blotscher German' Aerospace Research Establishment (DLR) Institute for Radio Frequency Technology D-8031 Oberpfaffenhofen, FRG Problems dealing with the X-SAR internal calibration and results of preparatory investigations using the DLR E-SAR are presented. The internal calibration occupies with the properties of the sensor itself. The receiverand transmitter inherent amplitude and phase distortions have to be measured in the laboratory and should be registered regularly during mission. Another very important point for radiometric calibration is the knowledge of the inflight antenna diagram. We plan to deploy a greater number of high precision calibration receivers on ground to register azimuth slices and lateron reconstruct the mainlobe of the inflight antenna pattern. Arising problems are discussed.