The Rayleigh Rice vector perturbation theory of diffraction is used to relate surface topography to scatter.
In fact, this relationship allows the calculation of common surface roughness parameters (power spectrum, rms
roughness, average surface wavelength, etc.) from the BRDF under the conditions that the surface is smooth,
clean and front surface reflective. The theory can also be used to predict situations where the topography of
such a surface will produce no scatter. That is, surface scatter can be eliminated under certain combinations
ofviewing parameters. Under these conditions, the measured BRDF is the result of contaminants and subsurface
defects. This paper presents previously unpublished material, discusses the theoretical basis for the effect, and
gives experimental results.