基于MB模型的简化偏振BRDF模型建立与仿真

Establishment and simulation of simplified polarimetric BRDF model based on MB model

偏振BRDF模型的计算往往非常复杂,为了简便准确地获取伪装目标和背景的反射光偏振度差值,采用特殊值法和理想化方法对Maxwell-Beard BRDF模型中的微面元分布函数和遮蔽函数进行简化,使微面元分布函数较Torrance-Sparrow模型更准确,较Maxwell-Beard模型更简单。然后利用Fresnel反射中物体对光线平行分量和竖直分量反射率不同的性质,采用物理理论分析的方法计算得到表示反射过程的Muller矩阵,并建立了其矢量BRDF模型。针对面内反射,利用Matlab对模型进行模拟,仿真结果证明:模型可以描述粗糙表面反射偏振特性。研究结果对研究粗糙表面反射偏振特性的影响因素及伪装目标偏振探测有一定的理论和实践意义。

The compute of p BRDF model is very complex in most cases. In order to get the contrast of degree of linear polarization（ DOLP） between camouflaged target and background accurately and conveniently, the distribution function of microfacet and shadowing function in the Maxwell-Beard BRDF model was simplified with the method of idealization and specific values. The distribution function of microfacet become more accurate than Torrance-Sparrow model and easier than Maxwell-Beard model.According to the property that there are differences between the rate of s component and the p component in Fresnel reflection, the Muller matrix which record the process of reflection was got. Then a polarimetric BRDF model was established by physical theoretical analysis. To cope with in-plane reflection, the p BRDF model was simulated by MATLAB and the results show it can describe the reflecting properties of rough surfaces. The model has theoretical and practical significance for the study of the influencing factors of the reflection by rough surface and polarimetric camouflaged target detecting.