Improved spectral polarized bidirectional reflectance distribution function model based on the Sellmeier equation

The existing polarized bidirectional reflectance distribution function (pBRDF) models only focus on the hemispherical distribution characteristics of polarization in a single wavelength, limiting the description of spectral polarization of objects. In this study, an improved spectral pBRDF model is proposed, incorporating a wavelength-dependent complex refractive index into the specular reflection component and volume scattering component. The Sellmeier equation represents the spectral complex refractive index. Then, the model parameters of coating materials are determined through the measurements of the degree of linear polarization (DoLP). The comparison between the simulation and measurement results demonstrates that the DoLP calculated by the proposed spectral pBRDF model fits in the measured data well, indicating that the proposed model can accurately simulate the spectral polarized property.