A SIMPLE GEOMETRICAL MODEL FOR ANALYZING THE SPECTRAL RESPONSE OF A CITRUS CANOPY USING SATELLITE IMAGES

A simple geometrical model has been proposed for a citrus canopy. We assume the citrus orchard to be a lattice structure, with the trees positioned at its points and where the composite-scene reflectance is the sum of the reflectance of its individual components as weighted by their respective surfaces within a unit area. The model has been used to analyse the citrus spectral response obtained from Landsat-5 TM images for winter and summer, where the status of the orchard is different. The correlations between spectral and geometrical data show the influence of per cent crop cover, shadows and background in the composite scene reflectance. We conclude thai the summer images could be more useful than the winter ones for parcel classification according to per cent crop cover. © 1990 Taylor & Francis Group, LLC.