A note on the theory of scattering from an irregular surface

Integral formulas are developed directly from vector field theory for scattering by a perfectly conducting irregular surface at very short wavelengths. It is shown that, in the optical limit, the back-scattered field has no cross polarized component. When the integrals are evaluated asymptotically by the method of stationary phase, it turns out that to a first approximation the back scattering cross section is proportional to the average number of specular points which are illuminated at a given angle of incidence and to the geometric mean of the principal radii of curvature at those points. The scattering problem is, thus, transformed to a problem in the statistical geometry of irregular surfaces.