【摘要】 简述了冠层辐射分布的常用研究方法,介绍了光线跟踪技术的原理及其在辐射传播中的应用。针对树木模型提出正向光线跟踪的辐射传输模型,并详细阐述了模型假设、处理流程与主要算法。该模型针对光合有效辐射在树木冠层中的传输过程,采用正向光线跟踪的方法进行模拟,最后利用HSV与RGB颜色空间转换的特殊方法,直观表达了冠层辐射分布结果。在叶片光学特征分析的基础上,将该模型应用于林木冠层PAR分布模拟中,以得到冠层的反射率、透射率和吸收率等重要参数。结果表明,模拟数据与实测数据偏差不大,验证了正向光线跟踪的辐射传输模拟是有效的。更多还原

【Abstract】 The common methods about research on the distribution of radiation in canopy are introduced.The principle of ray-tracing technology and its application in radiation transmission are described.A radiation transfer model is proposed for tree model based on forward ray tracing.The model hypothesis,processing flow and primary algorithm are expounded.Forward ray tracing is used to simulate transmission course of photosynthetically active radiation in tree canopy.Finally the special conversion method between HSV and RGB color space is adopted to clearly express distribution of radiation in canopy.On the basis of analyzing optical characteristics of leaves,the radiation transfer model is applied in the simulation of distribution of PAR in canopy.At the same time,we can get the reflectance rate,transmission rate and absorption rate.The simulative data have little difference with the actually measured data which indicated that the radiation transfer model based on forward ray tracing is effective.更多还原