Electromagnetic wave scattering from gaussian random rough surfaces

Abstract

Electromagnetic waves scattering from rough surfaces is studied here when a planewave is incident upon a surface which is assumed to be perfectly conducting and of Gaussian distributed height profile. Statistical characteristics of the scattered fields are described by a vector $\mbox{\underline{V}} = \mbox{\underline{K}}_1 - \mbox{\underline{K}}_2$, where $\mbox{\underline{K}}_1$ and $\mbox{\underline{K}}_2$ are wave vectors of incident and scattered fields, respectively, rather than by usual incident and scattered angles. The descriptions of scattered fields in the V space provides clearer understanding of scattering mechanisms and enables one to calculate scattering field patterns. Means and Variances of the scattered fields are derived for various values of the surface roughness. It is shown that non zero means of scattered fields occur only in the specular direction for the Gaussian random surface. For non specular directions, therefore, variance of the scattered field becomes its average intensity. The most energy of the incident wave is reflected to the specular direction for the slightly rough surface and scattered into various directions for the very rough surface.