A generalized soil-adjusted vegetation index
A generalized soil-adjusted vegetation index
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DOI：
10.1016/s0034-4257(02)00048-2
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发表时间：
2002-10-01
影响因子：
13.5
通讯作者：
Meliá, J
中科院分区：
文献类型：
--
作者：
Gilabert, MA;González-Piqueras, J;Meliá, J
目前，通过遥感对植被覆盖进行的实际监测涉及到利用植被指数，其中大多数是红（R）和近红外（NIR）光谱波段反射率的函数。介绍了一种基于简单植被冠层模型的广义土壤调节植被指数（GESAVI）。根据土壤线参数（A和B）定义为：GESAVI=（NIR - BR - A）/（R + Z），其中Z与土壤线和植被等值线之间交叉点的红色反射率有关。由于Z是土壤调节系数，因此可以认为该新指数属于SAVI系列。为了分析GESAVI的敏感性，土壤亮度和土壤颜色，高分辨率的反射率数据从两个实验室的实验和数据通过应用辐射度模型来模拟异质性植被冠层场景。计算了不同土壤背景下的维斯指数（包括GESAVI、NDVI、PVI和SAVI族指数），并分析了其与叶面积指数的相关性。结果证实，GESAVI在大多数情况下对土壤背景的敏感性较低，因此成为一个非常有效的指标。这种良好的指数性能是由于NIR-R平面中的等值线既不平行于土壤线（如PVI所要求的），也不收敛于原点（如NDVI所要求的），而是在NIR和R的负值区域中收敛于原点和无穷远之间的某个地方。这个收敛点不一定位于平分线上，如其他SAVI系列指数所要求的那样。(C)2002年由Elsevier Science Inc.出版
Operational monitoring of vegetative cover by remote sensing currently involves the utilisation of vegetation indices (VIs), most of them being functions of the reflectance in red (R) and near-infrared (NIR) spectral bands. A generalized soil-adjusted vegetation index (GESAVI), theoretically based on a simple vegetation canopy model, is introduced. It is defined in terms of the soil line parameters (A and B) as: GESAVI=(NIR - BR - A)/(R + Z), where Z is related to the red reflectance at the cross point between the soil line and vegetation isolines. As Z is a soil adjustment coefficient, this new index can be considered as belonging to the SAVI family. In order to analyze the GESAVI sensitivity to soil brightness and soil color, both high resolution reflectance data from two laboratory experiments and data obtained by applying a radiosity model to simulate heterogeneous vegetation canopy scenes were used. VIs (including GESAVI, NDVI, PVI and SAVI family indices) were computed and their correlation with LAI for the different soil backgrounds was analyzed. Results confirmed the lower sensitivity of GESAVI to soil background in most of the cases, thus becoming a very efficient index. This good index performance results from the fact that the isolines in the NIR-R plane are neither parallel to the soil line (as required by the PVI) nor convergent at the origin (as required by the NDVI) but they converge somewhere between the origin and infinity in the region of negative values of both NIR and R. This convergence point is not necessarily situated on the bisectrix, as required by other SAVI family indices. (C) 2002 Published by Elsevier Science Inc.