Polarimetric scattering analysis for accurate observation of stricken man-made targets using a rotated coherency matrix

This paper investigates polarimetric scattering features generated from man-made targets for accurately observing stricken residential area by making full use of quad. polarimetric SAR data set. First, we propose a simple improvement of the scattering power decomposition method by introducing a unitary rotation of the coherency matrix. It is found from the results of the POLSAR image analysis for a mountainous region including some stricken residential areas that by carrying out the rotation procedure, double-bounce scattering contribution can be enhanced even when the targets are oriented and/or set on small inclined ground plane. This peculiar scattering feature is utilized as a useful marker for precisely detecting man-made targets. To verify the generating and enhancing mechanism of the double-bounce scattering, we also carry out the Finite-Difference Time-Domain (FDTD) polarimetric scattering analysis for a simplified man-made target model. The dependency of the polarimetric scattering feature on the variation of squint angle is investigated. It is confirmed from the FDTD analysis for oblique squint angular range that by applying the rotation procedure before the scattering power decomposition, the double-bounce scattering contribution tends to be enhanced, and the volume scattering becomes small.