The variation of bistatic rough surface scattering cross section for a physical optics model

The general behavior of a rough surface scattering cross section is examined as a function of incident and scattering angles, surface roughness, dielectric constant, and polarization for physical optics (PO) conditions. Quite distinct and complicated variations are observed. For some conditions, deep nulls occur in the normalized bistatic cross sectionsigma deg; as a function of seatlering angle, while other parameter sets yield no such pattern. These results are analyzed and interpreted. The differences in the angular variation insigma degfor different polarizations suggested that, for a given set of conditions, it would be possible to minimize the scattering from a rough surface. This topic is addressed in the second part of the paper. For the case of a given incident polarization, a technique is presented to optimize the bistatic observation of terrain scattering by using combinations of receiver polarization which vary as the scattering angles are changed.