 The polarized bi-directional reflectance distribution function, PBRDF, model is used to relate the properties of target materials to the polarization of incident and reflected light. The pre-stirmer, PG, model was the first strictly PBRDF model to be officially released, but it has some limitations. This paper examines the assumptions of the PG model and proposes a new polarized PBTDF model, which takes into account the effects of diffraction and transmission. The proposed model is then tested against experimental data and found to have a higher degree of accuracy and precision than the original PG model. This article was authored by Chang Fu, Shen Weilu, Diyang, and others.