Airborne InSAR Interferometric Phase Analysis, Unwrapping Method, and Fast Implementation in Low Coherence Areas

Due to synthetic aperture radar (SAR) imaging geometry and scattering characteristics, there are some low coherence areas in interferometric SAR (InSAR) data, such as shadow and water, where the interferometric phase is discontinuous. Therefore, it is difficult to prevent the phase error spreading in the process of phase unwrapping. In this article, the characteristics of the interferometric phase in the shadow and water areas are theoretically analyzed, respectively. According to the analysis, instead of the usual integral path setting strategy, a novel unwrapping method based on the phase compensation is proposed to avoid the unwrapping error. Besides, a fast implementation method of the quality-guided unwrapping algorithm based on the heap sort is proposed to improve the efficiency. The experiment by real airborne InSAR data validates the effectiveness of the proposed method.