COMPARATIVE-STUDY OF AVHRR RATIO VEGETATION INDEX AND NORMALIZED DIFFERENCE VEGETATION INDEX IN DISTRICT LEVEL AGRICULTURAL MONITORING

With the temporal profiles of mean values of ratio vegetation index (RVI) and normalized difference vegetation index (NDVI) and their standard deviations over the crop growth cycle for two districts displaying more than 90 per cent of the area sown under wheat, this article indicates the better sensitivity aspect of RVI as compared to NDVI during emergence-crown root initiation-late tillering-jointing-near flowering stages of the crop growth cycle; and suggests a combined use of RVI and NDVI for crop growth oriented studies. The relative narrowness of the standard deviation of RVI in these early crop growth stages as compared to that for the NDVI suggests that the RVI possesses better information content integration capabilities.