Experimental observations of the forward scattering of microwaves from a rough dielectric surface

An experimental investigation was conducted to determine the nature of bistatic scattering from rough dielectric surfaces at 10 GHz. This paper focusses specifically on the dependence of coherent and incoherent scattered fields on surface roughness for the specular direction. The measurements, which were conducted for a smooth surface and for three rough surfaces with ks=0.5, 1.39, and 1.94, included observations over the range of incidence angles from 20° to 65° for both horizontal and vertical polarizations. The lowest-order physical optics model was found to adequately describe the observations for both coherent and incoherent scattering, except in the region of the Brewster angle for υ-polarized scattering. A second-order solution is proposed which appears to partially address the deficiency of the physical optics model in this region for incoherent scattering