COMPARISON OF EXPERIMENT WITH MONTE-CARLO SIMULATIONS ON A REFLECTIVEGAP USING A DETAILED SURFACE-PROPERTIES MODEL

The spatial distribution of light through a rectangular gap bounded by highly reflective, diffuse surfaces was measured and compared with th e results of Monte Carlo simulations. Incorporating radians properties for real surfaces into a Monte Carlo code was seen to be a significan t problem; a number of techniques for accomplishing this are discussed . Independent results are reported for measured values of the bidirect ional reflectance distribution function over incident polar angles fro m 0 to 90 deg for a semidiffuse surface treatment (Krylon(TM) flat whi te spray paint). The inclusion of this information into a Monte Carlo simulation yielded various levels of agreement with experimental resul ts. The poorest agreement occurred when the incident radiation was at a grazing angle with respect to the surface and the reflectance was ne arly specular.