农作物冠层BRF及波谱的计算机模拟及其验证

Computer Simulation and Validation of BRF Data of Vegetation Canopy

计算机模拟模型是以植被真实三维结构场景为基础,模拟植被冠层的辐射特性。本文以冬小麦为例,利用辐射度方法模拟了冬小麦在不同LAI下的冠层二向反射因子(BRF)及其波谱特征;为了验证并评价模拟数据的质量,将模拟冠层BRF数据与实测数据进行了比较,并将计算机模拟波谱数据与Prosail模型模拟波谱及实测波谱进行了比较。通过研究可以得到以下结论:(1)LAI是植被群体重要的结构参数,对于同一品种的植被可以用LAI来描述植被的生长进程;(2)基于计算机模拟的冠层BRF数据具有一定的可靠性,能够满足实际研究的需要,因此可以把计算机模拟冠层BRF数据作为实测数据用于研究,以弥补因各种条件限制无法得到实测数据的缺憾。

Computer simulation model is based on the 3D realistic structure of vegetation, and can simulate the canopy radiation regime. In this paper, taking winter wheat as an example, its canopy BRF and spectrum with different LAI are simulated. And in order to qualify the computer simulated results, firstly, the computer simulated BRF is compared with the measured data. In addition, the computer simulated spectrum is compared with the simulated and measured spectrum Prosail model using. From this study, some conclusions are drawn： （1） LAI is an important structure parameter for vegetations, and can depict their growth course ; （2） canopy BRF and spectrum based on computer simulation model are reliable and their precision can meet study demands. So computer simulated results can be considered as the measured data for research under certain conditions.