Motion Compensation for Accurate Position Estimation of Ground Moving Targets using the Multi-Channel Airborne System DBFSAR

The accurate estimation of the target’s position on the ground is a crucial step for air-based surveillance systems. For the particular case of radar systems with multiple receive channels, the target’s position on the ground can be accurate-ly obtained after estimating its direction-of-arrival (DOA) angle. The problem is that, in practice, the aircraft’s motion tilts the antenna array and introduces undesired phase differences among the receive channels. Consequently, the DOA angle estimation accuracy can be severely impacted. This paper presents a fast and robust algorithm for correcting the undesired phases differences introduced by the aircraft’s motion among the multiple receive channels. The proposed algorithm is tested and validated using simulated radar data as well as radar data acquired with the DLR’s new multi-channel airborne system digital beamforming SAR (DBFSAR)