SAVI (Soil Adjusted Vegetation Index) of the 2005 Landsat Thematic Mapper Image

Soil Adjusted Vegetation Index (SAVI) produced from the 2005 Landsat Thematic Mapper(ETM) image. SAVI is a means of monitoring density and vigour of green vegetation growth using the spectral reflectivity of solar radiation. It is computed as follows:( (NIR-RED) / (NIR+RED+L))*(1+L), where NIR (Near Infra-Red) is the TM band 4 (0.76-0.9 micrometers), RED is band 3 (0.78-0.82 micrometers), and L is the correction factor whose values range from 0 (high vegetation cover) to 1 (low vegetation). L=0.5 was used. The index has been designed to correct for high soil reflectance in arid regions.本数据集为基于2005年Landsat专题制图仪（Thematic Mapper，ETM）影像生成的土壤调节植被指数（Soil Adjusted Vegetation Index，SAVI）。土壤调节植被指数是一种依托太阳辐射光谱反射率，监测绿色植被生长密度与活力的指标。其计算公式为：((NIR-RED) / (NIR+RED+L))*(1+L)，其中近红外（Near Infra-Red，NIR）对应TM第4波段（波长范围0.76~0.9微米），红光（RED）对应TM第3波段（波长范围0.78~0.82微米）；L为校正因子，取值区间为0（高植被覆盖度）至1（低植被覆盖度），本次计算采用L=0.5。该指数专为校正干旱区域的高土壤反射率而设计。