An analysis of coherence optimization methods in compact polarimetric SAR interferometry

The coherence optimization methods of compact polarimetric SAR interferometry (PolInSAR) are analyzed in this paper. Coherence optimization for compact PolInSAR can be performed directly in the two-dimensional observation space of the CP system without the reconstruction of the pseudo fully PolInSAR covariance matrix. The performance of different compact polarimetric modes for coherence optimization is evaluated both theoretically and experimentally and compared to the capabilities of a fully polarimetric (FP) system. It is observed that there is a significant loss in coherence of 5 10% when CP modes are available. But the trend of the coherence histograms for CP case is closed to the corresponding FP case. This study shows that the degree of coherence from a CP architecture carries enough information for PolInSAR applications.