Green's function refinement as an approach to radar backscatter: general theory and applications to LGA scattering from the ocean

We present a new approach to the computation of radar returns from dielectric bodies whose boundary is the deformation of a plane surface. The method relies on combining a systematic improvement in the Green's function with a good approximate choice of local boundary condition. In this paper, the general theory is presented together with a simple application where the Green's function is that for a lossy dielectric half-space. We derive the root radar cross section (RCS) for a statistical surface and the mean backscatter RCS for a rough surface. We explore the applications to low-grazing-angle (LGA) scattering from statistical surfaces with an ocean-like spectrum and demonstrate that such a model explains some of the previously unexplained LGA phenomena, such as the absolute and relative levels of the vertical (VV) and horizontal (HH) channel RCS measurements.