Comparison of the NDVI, ARVI and AFRI vegetation index, along with their relations with the AOD using SPOT 4 vegetation data

Abstract

For decades, the satellite images acquired in visible and infrared bands have been used for environmental monitoring. In this purpose, the normalized difference vegetation index (NDVI) is the commonly used vegetation index model for canopy monitoring and biomass assessment. However, due to the fact that the NDVI index is susceptible to various outside influences - most notably the atmospheric disturbance and currently more bands are provided by satellite platforms - additional indexes have been developed to counter these effects. This paper explores two such indexes - the Aerosol Free Vegetation Index (AFRI) and the Atmospherically Resistant Vegetation Index (ARVI). Comparisons were made with the NDVI index to see if they indeed performed better. The relationship of the different outcomes exhibited between the indexes with the aerosol optical depth (AOD) was analyzed and exploited to see if this scattering effect was more reduced than with NDVI. In general, the results showed that the AFRI and ARVI (with gamma = 1) indeed did perform better than their NDVI counterpart study with the related channels were employed.