Simplified algorithm for detecting oriented man-made objects using correlation coefficients in circular polarization basis

This paper proposes a simple algorithm to precisely detect man-made objects with any alignment to radar illumination direction. Here, a couple of polarimetric indices, i.e. the copol. correlation coefficient in LR circular polarization basis, and its normalized one are utilized in the algorithm, since the former is emphasized in reflection symmetry (RS) as normally aligned man-made objects area, whereas the latter is enhanced in Non-RS as obliquely aligned man-made objects area. The appropriate thresholds for switching the polarimetric indices are determined by considering the result of polarimetric scattering analysis for simplified man-made objects model. The Finite-Difference Time-Domain (FDTD) method is utilized for the analysis. It is finally confirmed from the result of the PolSAR image analysis that the proposed algorithm is very effective for detecting the man-made objects not only normally but also obliquely alignment to the radar illumination direction.