ABSTRACT
Polarization is indicative of small-scale surface roughness, and photometry indicates large-scale surface roughness [1]. These phenomena are evident from measurements on natural and contrived surfaces. The original surface-scattering research was based on laboratory simulation of the lunar surface from astronomical observations prior to the lunar landing. It was found that large-scale irregularities on a surface cause shadowing to exert a major influence on the surface photometric scattering as well as on polarization. A dust coating on a coarse surface modifies both the photometric and polarimetric scattering functions. The dust coating causes depolarization and generally increases surface brightness. Percent polarization is found to be inversely proportional to surface optical albedo. In remote sensing, the fine structure of targets is related to percent polarization. Polarized retroreflectance is related to both coarse and fine structure of surfaces and is a valuable key to assessing contributing factors. Also, polarization can be used to advantage in military applications to distinguish targets from backgrounds.
