NOAA-AVHRR DATA-PROCESSING FOR THE MAPPING OF VEGETATION COVER

The NOAA-AVHRR images have been widely used for global studies due to their low cost, suitable wavebands and high temporal resolution. Data from the AVHRR sensor (Bands 1 and 2) transformed to the Normalized Di fference Vegetation Index (NDVI) are the most common product used in g lobal land cover studies. The purpose of this Letter is to present the vegetation, soil, and shade fraction images derived from AVHRR, in ad dition to NDVI, to monitor land cover. Six AVHRR images from the perio d of 21 to 26 June 1993 were composed and used to obtain the above men tioned products over Sao Paulo State, in the south-east of Brazil. Veg etation fraction component values were strongly correlated with NDVI v alues (r = 0 . 95; n = 60). Also, the fraction image presented a good agreement with the available global vegetation map of Sao Paulo State derived from Landsat TM images.