基于辐射传输模型的FPARgreen与几种植被指数的关系研究
Relationship between FPAR green and several vegetation ndices based on radiative transfer model

为了更好地分析不同植被指数与真实光合有效辐射吸收比例（FPARgreen）的相关性，利用PROSPECT+SAIL模型对FPARgreen进行计算，同时模拟在植被指数类别、叶倾角分布和土壤背景反射率等不同输入参数条件下的多种常见植被指数，观察各植被指数与FPARgreen线性拟合精度，寻找最优的植被指数。结果表明，NDVI、SAVI和EVI都是反演FPARgreen较好的植被指数。
The fraction of absorbed photosynthetically active radiation (FPAR) is an important parameter to estimate the net primary productivity (NPP) of terrestrial ecosystem by remote sensing.However,when the leaf area index (LAI) and other parameters increase,FPAR becomes less sensitive to NPP at the same time.In order to analyze a more accurate linear relation between NPP and FPAR,some scholars point out a concept in allusion to the absorbed photosynthetically radiation of chlorophyll FPAR absorbed by photosynthetically active vegetation (FPARgreen) which is more accurate and helpful for monitoring and analyzing crops compared with FPAR.Nowadays FPARgreen is extracted by vegetation index inversion,and its final inversion precision is affected by the vegetation index selected.The PROSPECT+SAIL model was used to calculate the true FPARgreen.Various common vegetation indices were stimulated to make linear fitting with the linear fitting precision of each vegetation indices.Some parameters including leaf inclination angle and soil reflectance were modulated to screen the best vegetation index.