Polarimetric scattering feature estimation for accurate wetland boundary classification

This paper investigates polarimetric scattering characteristics from boundary region between the water area and the surrounding emerged plants in wetland, and proposes a simple true water area estimation method, by using both Φ_HH - Φ_VV and P_d in polarimetric synthetic aperture radar (PolSAR) im age analysis. The true water area includes not only the body of water but also the water area under emerged-plants and/or floating-leave plants in wetland. To verify the generating mechanism of the specific polarimetric scattering features, the Finite-Difference Time Domain (FDTD) polarimetric scattering analysis is also carried out for a simplified boundary model, which simulates the local boundary region around the wetland and consists of lots of vertical thin dielectric pillars on a dielectric plate. Taking into account the polarimetric feature obtained by both the FDTD and PolSAR image analyses, one can distinguish the actual water area from the emerged-plants around a wetland, even when the water area is concealed by emerged plants and/or floating-leave plants. Resultantly, it is found that by using the proposed simple classification markers, one can estimate the true water area boundary for wetland and the surrounding emerged-plants.