粗糙表面偏振二向反射特性建模方法研究

针对地面目标光学偏振特性预测对基础材质粗糙表面偏振二向反射特性建模的需求,对比分析国内外常用的经验、物理和半经验等3种偏振二向反射分布模型的优缺点及其适用范围,得出半经验模型更适用于地面目标光学偏振特性预测.在此基础上,研究基于半经验Priest-Gemer模型的参数反演方法,并提出相应的测试方法,设计试验测试验证平台.最后,对模型中的影响因子进行仿真分析,分析结果表明：目标表面偏振二向反射特性与表面纹理特征、复折射率、入射光角度、探测方位角、天顶角等因素相关,且复折射率对目标表面反射率及反射光的偏振度影响较大,粗糙度会影响遮蔽与阻挡效应,使其产生突变效应.

Methods of Modeling of Polarized BRDF of Rough Surfaces

The advantages and disadvantages of three conventional types of polarized BRDF （Bidirectional Reflectance Distribution Function） models, namely, empirical models, physical models and semi-empirical models, and their scopes of application are analyzed and compared to meet demands of prediction of the polarization characteristics of ground targets for BRDF modeling of the rough surfaces of basic materials. The conclusion is that semi-empirical models are more appropriate for prediction of the polarization characteristics of ground targets. Parameter inversion methods based on the semi-empirical Priest-Germer polarized BRDF models are studied. An associated test method is proposed and a test and validation bench is designed. Impact factors of Pries~Germer models are simulated and ana- lyzed and the results show that the polarized BRDF characteristics of rough surfaces of ground targets are correlated to factors including the roughness of surfaces, complex refraction index, angles of incidence and angles of probing and zenith angles. Among them, complex refraction index has more impact on reflectivity albedo and the degree of polarization of reflected lights while surface roughness leads to a sharp change of the shadowing and obscuration function.