The Theoreticalmodel Building And Experimental Research Of Bidirectional Reflectance Distribution Function Of Polytype Surfaces

Bidirectional Reflectance Distribution Function (BRDF) is used to describe thescattering characteristic of the roughness surface of target material; it is mainlydetermined by the surface roughness, dielectric constant, exposure or reflectivewavelength and polarization etc. BRDF is used broadly in scattering, radiation inoptical band and microwave band and remote sensing, and it also used in the risingresearch field of computer vision. Based on the summarization of domestic andforeign measurement experience; we developed a suit of BRDF testing systemcontrolled microcomputer. The wavelength range of the laser as the light source oftesting system are from visible light band (0.6328μm), near-infrared band (1.34μm), middle-infrared band (3.39μm) to far-infrared band (10.6μm). The materialhemisphere spatial reflection characteristic and spectral characteristic can bemeasured using this experiment equipment.The physical surface is usually irregular and height random various, but thesurface scattering condition is effected by the surface form, so the tool which couldinvestigate the irregular surface is needed. Fractal theory is a powerful tool ofstudying and dealing with the irregular figure with the scale characteristic. It candescribe the complexity of the surface topography through the simple parameter, sofractal theory has offered a kind of effective means of describing the surfacetopography from microscopic molecule to macroscopical yardstick. In this paper, theroughness of certain granite surface (grinding and polishing treatment) was measuredby needle touched method firstly and the simple outline profile was drawn. On thebasis of measuring the parameter in experiment, the random rough surface issimulated utilizing the fractal theory, it is compared with surface measured actually;light scattering from randomly rough surfaces is investigated by numericalsimulation.In this paper, first of all, the BRDF experiment bench is rebuild, a properdetector is chosen. And then, the theoretical surface (definite basal area and height,definite basal area and height various, definite height and basal area various, variousbasal and height) is simulated by the method of two dimensional regular multiplefractal theory, moreover, the scattering is simulated by monte-carlo methods, verifies...