Renhorn Ingmar G E, Hallberg Tomas, Bergström David, Boreman Glenn D
FOI-Swedish Defense Research Agency, Linköping, Sweden.
Opt Express. 2011 Jan 17;19(2):1027-36. doi: 10.1364/OE.19.001027.
A modeling procedure is demonstrated, which allows representation of polarization-resolved BRDF data using only four parameters: the real and imaginary parts of an effective refractive index with an added parameter taking grazing incidence absorption into account and an angular-scattering parameter determined from the BRDF measurement of a chosen angle of incidence, preferably close to normal incidence. These parameters allow accurate predictions of s- and p-polarized BRDF for a painted rough surface, over three decades of variation in BRDF magnitude. To characterize any particular surface of interest, the measurements required to determine these four parameters are the directional hemispherical reflectance (DHR) for s- and p-polarized input radiation and the BRDF at a selected angle of incidence. The DHR data describes the angular and polarization dependence, as well as providing the overall normalization constraint. The resulting model conserves energy and fulfills the reciprocity criteria.
展示了一种建模程序，该程序仅使用四个参数就可以表示偏振分辨的双向反射分布函数（BRDF）数据：有效折射率的实部和虚部，一个考虑掠入射吸收的附加参数，以及一个根据选定入射角（最好接近正入射）的BRDF测量确定的角散射参数。这些参数能够在BRDF大小变化三个数量级的情况下，对涂漆粗糙表面的s偏振和p偏振BRDF进行准确预测。为了表征任何感兴趣的特定表面，确定这四个参数所需的测量是s偏振和p偏振输入辐射的定向半球反射率（DHR）以及选定入射角下的BRDF。DHR数据描述了角度和偏振依赖性，并提供了整体归一化约束。所得模型守恒能量并满足互易准则。
