Automatic intelligent full angular BRDF measurement system based on virtual instrument technology

Intensity distribution of scattered light contains important information relates to surface material and roughness. The above distribution is difficult to model and simulate, and which requires sufficient experimental measurement data to validate. Bidirectional reflection distribution function (BRDF) can express it. However, measuring hemispheric spatial distribution of BRDF requires huge work. An automatic intelligent full angular measuring device is designed in this paper. A digital light intensity sensor is designed with high sensitivity and wide measuring range. Steering gears are used to design a high precision two dimensional turntable, and which are controlled by a micro controller. An intelligent acquisition system is designed by virtual instrument technology, and which could establish BRDF model automatically according to a shallow neural network algorithm. Results show that scattered light of a dielectric rough surface has obvious peak movement with increase of roughness when linearly polarized light is irradiated. A metal rough surface has no the peak movement phenomenon. The above shallow neural network BRDF model is consistent with experimental data, and this intelligent measure system has application value in scattering light research of rough surface.