Doppler ambiguity resolver based on the interferometric spectrum´s quality

The determination of Doppler ambiguity number (DAN) is an essential procedure for the interferometry synthetic aperture radar (InSAR) processing. DAN can be estimated by the data-based method, namely Doppler ambiguity resolver (DAR). However, various contrast scenes affect the precision of DARs. In this paper, a novel contrast-independent DAR is presented. It is based on the relationship between the interferometric spectrum´s quality and DAN errors, i.e., as DAN errors increase, the quality of the interferometric spectrum is lowered. The proposed algorithm employs the candidate DAN to make linear range cell migration correction (RCMC) to the range-compressed data, and evaluates the spectrum´s quality of the interferogram. The candidate DAN which optimizes the interferometric spectrum´s quality is treated as the final estimation result. Simulation results are provided to demonstrate the performance of the proposed approach.