Compensation of residual motion errors in airborne repeat-pass insar with trajectory angle estimation using co-registration offset

Due to the limited accuracy of navigation systems, airborne InSAR processing is affected by residual motion error (RME). The phase-based methods such as multi-squint are usually based on the assumption that the RME is quite small. Different from dual-antenna InSAR systems, larger RME occurs in repeat-pass InSAR experiments since the RMEs are independent between two images, which causes decorrelation and reduces compensation accuracy in the phase-based method. With the improvement of SAR image resolution in recent years, the accuracy of co-registration is also improved. In this paper, a method for estimating the residual rotation angle of radar trajectory based on co-registration offset is proposed to compensate the RME when facing decorrelation. After that, the entire process flow of compensating RME is given. The computer simulation results have been conducted to verify the effectiveness of the proposed approach.