作物冠层BRDF的Monte Carlo模拟与分析

Crop canopy BRDF simulation and analysis using Monte Carlo method

该文构建了光子在作物冠层传输的随机过程,采用蒙特卡罗(M on te C arlo)方法模拟了作物冠层BRDF。对比蒙特卡罗模型和M CRM模型,分析了叶倾角(LAD)与叶面积指数(LA I)对两模型BRDF的影响,并对其中的变化给出了合理的解释。研究表明,两模型虽然在模拟的BRDF数值上有一定差异,但在不同LAD和LA I对BRDF的变化趋势上达到了较好的一致性。最后,用实测BRDF数据验证和分析蒙特卡罗模型,结果表明,蒙特卡罗模型与实测BRDF较为吻合,蒙特卡罗模型可以作为其他作物冠层BRDF前向模拟的有效验证工具。

This author designs the random process between photons and crop canopy, A Monte Carlo model has been developed to simulate the Bi-directional Reflectance Distribution Function （BRDF） of crop canopy. Comparing Monte Carlo model to MCRM model, this paper analyzes the variations of different LAD and LAI of these two models and gives the reasonable explanation, it can be concluded that although there are some differences in BRDF value, the BRDF change trend with varying LAD and LAI reaches a good agreement. In the end using field measured BRDF data to validate Monte Carlo model, the results show that the simulated BRDF with Monte Carlo model is in good accordance to the field data. Therefore, Monte Carlo model can provide the effective validation tool of other forward BRDF simulation models of crop canopy.