BEYOND THE KIRCHHOFF APPROXIMATION-II ELECTROMAGNETIC SCATTERING

In a previous paper the momentum transfer expansion was introduced for scalar wave scattering. It was shown that, using this expansion, one could obtain wavelength dependent curvature corrections to the Kirchhoff approximation. In this paper we extend the momentum transfer perturbation expansion to electromagnetic waves. Curvature corrections to the surface current are obtained. Using these results, the specular field and the backscatter cross section are calculated.