Optimization of BRDF measurement method using Spectralon white reflectance standard

There are two kinds of methods to measure the bidirectional reflectance distribution function (BRDF), direct method and relatively method. The relatively method is widely used because of its convenience and small error. However, the BRDF of the Spectralon white reflectance standard in relatively method was found to deviate from the Lambertian BRDF. It was found to vary with the angle of incidence, the wavelength of incidence and the states of polarization of the incident and reflected light. This paper proposes an optimized measurement formula of BRDF. The result is corrected. Taking the BRDF of standard roughness specimens for example, experimental results show that the measurement accuracy is improved comparing with the original formula. Finally the error analysis is carried out on the accuracy of measurement. The research has certain reference significance for the study of target characteristics on noncooperative target ranging.