Error analysis and calibration techniques for multichannel SAR instruments

Future spaceborne Synthetic Aperture Radar (SAR) systems will be based on multiple transmit/receive channels and use Digital Beam Forming (DBF) technique and on board processing to provide high coverage and high resolution simultaneously. Due to the necessary on board processing and required alignment between the signals from different channels by the multi-channel operation, a big challenge in the system calibration arises. To manage that issue, new techniques have to be identified and verified. This paper presents the analysis of the effect of system and calibration errors on the SAR image quality for an example multi-channel spaceborne SAR system, which should give a starting point in the calibration accuracy considerations. Further, some ideas for the error correction in the data processing are given and computation results shown.