基于Ross Thick-LiSparseR及Ross Thick-LiTransit的核驱动BRDF计算与评价

Calculation and Comment on BRDF Based on Ross Thick-LiSparseR and RossThick-LiTransit Kernels

核驱动BRDF模型是MODIS传感器用于计算全球地表反照率的AMBRALS算法系统所使用的模型。目前AMBRALS算法系统的几何光学散射核为LiSparseR核,它不能完全避免反射率为负的情况,并在遥感像元尺度应用互易原理的理论依据不充足。几何光学核LiTransit核兼有LiSparse核向LiDense核过渡的优点,比LiSparseR核更符合几何光学模型的基本原理。本文研究了基于LiSparseR核及LiTransit核驱动的方向反射率计算方法,并进行了比较验证。

Kernel driver BRDF model is a model used by the AMBRALS which is an algorithm for MODIS land surface albedo products.In the onboard version of AMBRALS,the LiSparseR Geometric-Optical（GO） kernel is used.That the negative reflection can not be avoided completely by using LiSparseR and the reason of using principle of reciprocity in the element criterion is insufficient.But a new derived kernel-LiTransit is good at transition from LiSparse kernel to LiDense kernel,and accords more with the basic principle of GO model than LiSparseR.The computational methods of directional reflection using LiSparseR and LiTransit kernels are studied,compared and confirmed in this paper.