In this paper the principal elements of the full wave approach to problems of scattering and depolarization by rough surfaces are summarized. Both deterministic and random rough surfaces are considered in detail and the full wave solutions are compared with earlier solutions based on physical optics and perturbation theories. It is shown that since the full wave approach accounts for both specular point scattering as well as Bragg scattering in a self-consistent manner, it resolves the discrepancies between the physical optics and perturbation solutions and bridges the wide gap between them. Thus, on applying the full wave approach to scattering by composite random rough surfaces it is not necessary to restrict the analysis to surfaces that can be treated as perturbed physical optics problems. The full wave solutions are shown to satisfy duality,reciprocity and realizability relations in electromagnetic theory and the results are invariant to coordinate transformations. The full wave approach also accounts for coupling between the radiation fields, the lateral waves and the surface waves that constitute the complete expansions of the fields and it can be applied directly to problems of scattering at near grazing angles.
Ezekiel Bahar, Ezekiel Bahar,
"Scattering And Depolarization By Rough Surfaces Full Wave Approach", Proc. SPIE 0358, Applications of Mathematics in Modern Optics, (7 December 1982); doi: 10.1117/12.934075; https://doi.org/10.1117/12.934075