Scattering of electromagnetic waves by random rough surfaces with different scales of roughness

A unified full wave approach is used to determine the like and cross polarized cross sections of composite random rough surfaces with different scales of roughness. Traditionally, the solutions for such composite rough surfaces are expressed as sums of solutions based on the perturbation and the physical optics approaches. The full-wave solutions account for both specular point scattering and Bragg scattering in a unified, self-consistent manner. The incoherent radar cross sections are obtained by regarding the composite (multiple scale) rough surface as an ensemble of individual patches with arbitrary orientations.