Interactions of light with rough dielectric surfaces: spectral reflectance and polarimetric properties.

An understanding of the nature of the interactions of visible and near-infrared radiation (0.6 to 1.8 μm) with the surfaces of rock and mineral samples is necessary for both theoretical modeling and interpretation of remotely sensed data. The expected reflectance and polarization properties of light that has interacted with a rough dielectric surface through both Fresnel and Rayleigh mechanisms are examined. Reflectance and polarization of reflected light were measured in the visible and near-infrared wavelength range for slab samples of obsidian and fine-grained basalt specially prepared to controlled surface roughness.