A SCALE-BASED MODEL OF REFLECTIVITY

A computer simulation is described that models reflectivity as a set of discrete interactions, represented by perfectly reflecting, triangular mirrors fit to the surface using the patchwork method.(1) The model is based on a premise that topographically dependent phenomena, such as reflectivity, interact with surfaces over certain scales and that these interaction scales can be used to characterize the interactions for use in the design evaluation of reflective topographies. The simulation is performed on a reflective topography and the results are discussed. Results from the simulation, plots of degree of specular reflection versus patch area, or scale, show that modeling the surface as a collection of mirrors of decreasing size results in less light reflected in the specular direction, or more scattering. Increased scattering from a reduction in patch size, or size of the interaction, models the increased scattering due to a reduction in wavelength of the incident light and reduced scattering due to an increase in incident angle, both shown experimentally in specular reflectance measurements.