An Extension of a Complete Model-Based Decomposition of Polarimetric SAR Data

The model-based decomposition that originated from Freeman-Durden three-component decomposition (FDD) has been widely applied in polarimetric synthetic aperture radar (PolSAR) data processing for its clear physical interpretation and easy implementation. Numerous improvements have been proposed to settle the two main drawbacks of FDD, i.e., the incomplete utilization of the polarimetric information in the coherency matrix and the negative scattering power problem. Recently, Cui et al. proposed a complete model-based three-component decomposition which successfully settled the two aforementioned drawbacks. However, the three scattering components' powers are not totally derived using scattering models, and the remaining coherency matrix (RCM) obtained by subtracting the volume scattering component from the coherency matrix is not consistent with the models of surface and double-bounce scattering components. As an extension of Cui's method, this letter is dedicated to develop a novel method to discriminate the surface and double-bounce scattering components both using scattering models. With the orientation angle (OA) variation and helix angle (HA) variation compensated for the RCM, the RCM is automatically consistent with the models of surface and double-scattering components. The OA variation and HA variation compensation for the RCM is done by unitary transformations of the eigenvectors of the RCM. The powers of surface and double-bounce scattering components are positive. The effectiveness of the proposed method is demonstrated by processing the real PolSAR data.