ERS-1 multitemporal backscatter analysis of different types of land cover in Brazilian Amazonia

Three ERS-1 images acquired in 1992, 1993 and 1996 respectively, over the Tapajos National Forest, Brazilian Amazonia, were used and the results show that the pasture areas backscatter had a random behavior in all three images. Agricultural areas also had a random behavior in the three images, however their average backscatter was higher than the pasture average backscatter. The behaviors of regrowth at age ranged from 1 to 8 years affected by fire and regrowth at the same age but not affected by fire were different. Three different types of regrowth whose ages ranged from 9 to 15 years showed three different behaviors. Regrowths whose age vary from 18 to 22 years old showed behavior according to their previous land use. Three different types of primary forests also were analyzed and three different behaviors were found. This study shows that the previous land use can interfere in the multitemporal backscatter behavior of the land cover, and it was also inferred that multitemporal analysis can be useful for the building of automatic radar images classifiers, once different types of land covers present different behaviors.