期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B7
页码：1127-1132
出版社：Copernicus Publications
摘要：Among several vegetation indices, NDVI is the most extensively used index because of its ratioing properties and as it is simple to compute. But its usefulness in discriminating vegetation types with high cover density or high LAI (for example opium poppy and winter wheat) is limited due to saturation of NDVI values, insensitivity at high LAI's and variations in canopy density, resulting in confusion between crops like those mentioned above. Due to these limitations discriminating between poppy and wheat using NDVI is a problem. Weighted Difference Vegetation Index (WDVI) counters these limitations effectively by enhancing canopy reflectance component. The application of WDVI is observed to maximize the separation between winter wheat and opium poppy. The developed method is applied on IRS-1D LISS-III data sets covering parts of Madhya Pradesh and Rajasthan, India. For operational use of this index, interactive identification of soil pixels is tedious and error prone. To circumvent this difficulty authors propose a method for automatic extraction of soil and vegetation pixels using two date multispectral data (acquired during fallow and crop season). For automatic extraction of soil and vegetation pixels a modified version of WDVI, called as Inverse WDVI (IWDVI), termed as corrected red, is proposed. Advantages of this procedure are automatic identification of soil and crop land pixels
关键词：Vegetation index; WDVI; NDVI; wheat; poppy; season
