基于蒙特卡罗方法的森林冠层BRDF模拟

Forest Canopy BRDF Simulation Using Monte Carlo Method

蒙特卡罗(MonteCarlo)是一种随机统计方法,被广泛用于模拟可见光森林冠层BRDF(双向反射率分布函数)。基于蒙特卡罗方法构建了光子与植被冠层之间的随机过程,给出了蒙特卡罗模拟森林冠层的BRDF的具体实现方法。在此基础上,讨论了蒙特卡罗模拟中的关键技术:光子自由路径的计算;光子散射方向的确定;BRDF热点效应纠正;光子能量收集算法。实践表明,蒙特卡罗方法能准确模拟出森林冠层BRDF,并能作为其他森林冠层BRDF模型的有效检验工具。

Monte Carlo method is a random statistic method, which has been widely used to simulate the Bidirectional Reflectance Distribution Function （BRDF） of vegetation canopy in the field of visible remote sensing. The random process between photons and forest canopy was designed using Monte Carlo method. Then, several key techniques of Monte Carlo simulation including the calculation of photon free path, the determination of photon scattering direction, hotspot correction and the algorithm of photon energy collection were discussed, This research shows that Monte Carlo is an effective approach to simulate the forest canopy BRDF and can be used to validate other forest canopy BRDF models.