Micro-scale surface and contaminate modeling for polarimetric signature prediction

The optical properties of a surface may change signiflcantly in response to contaminants from the environment and/or human activity. We utilize a flrst principles, physics-based radiometric ray tracing software package to evaluate the spectral polarimetric bi-directional re∞ectance distribution function (p-BRDF) of the virgin and contaminated surfaces. In the absence of contaminants and allowing only single bounces, we flnd the simulated re∞ectance properties of randomly rough Gaussian surfaces to be well represented by micro-facet based p-BRDF analytical models. However the addition of contaminants introduces phenomenology that falls outside the basic assumptions of the micro-facet analytical p-BRDF models. We will present initial results of p-BRDF simulations of random Gaussian surfaces with liquid contaminants.