THE INTERACTIVE EFFECT OF SPATIAL-RESOLUTION AND DEGREE OF INTERNAL VARIABILITY WITHIN LAND-COVER TYPES ON CLASSIFICATION ACCURACIES

A study is made to asses the effect of spatial resolution on the degree of internal variability within land-cover classes and then to examine how this within-class variance affects classification accuracy. Airborne Multispectral Scanner data flown at 5 m resolution are degraded to simulate 10 and 20 m data. Classification accuracies within internally homogeneous classes are found to be high at all spatial resolutions. In contrast, classification accuracies of land-cover types characterized by a high degree of internal variability or scene noise improve by up to 20 per cent as spatial resolution is coarsened because the proportion of scene noise is reduced.