Use of Landsat TM Fraction Images to Quantify the Optical and SAR Data Relationships for Land Cover Discrimination in the Brazilian Amazonia

要旨

This paper presents a comparison between L-band HH JERS-1 SAR and Landsat TM data for land cover assessment in an Amazonian test site. For this, a study area located in the south of Rondônia State, western Brazilian Amazonia, was selected. Landsat TM data acquired on August 1st 1997 were converted to vegetation, soil, and shade fraction images, using a Linear Spectral Mixing Model. To compare JERS-1 and TM fraction images, a regression analysis technique was used. The multiple regression analysis showed coefficient of determination (R2) of 0.86 between SAR and the fraction images. Then multiple regression equation was used to produce an image with predicted SAR backscatter. There is a direct relationship between SAR and shade fraction images and an inverse relationship between SAR and soil fraction images. Based on these relationships, it can be pointed out the utility of SAR data as an alternative data source for land cover classification in the Amazonian region.