Vegetation study of Amazon using QSCAT in comparison with SASS, ESCAT and NSCAT

The Amazon basin presents a large geographical zone that has undergone significant land cover changes during the last few decades due to accelerated logging and other anthropogenic influences. Amazon forest consists of diverse types of vegetation, which vary with various geophysical factors, like latitude, moisture, rainfall etc. In this paper, variations in the radar backscatter measurements (σ°) from various scatterometers over the Amazon basin are presented for selected study regions. C-band σ° from ERS scatterometer (ESCAT) are found to exhibit a general decrease over the period 1992-1999. ESCAT and Ku band NASA scatterometer (NSCAT) σ° measurements are compared to study the multi-spectral signatures and are, in general, found consistent. Ku band σ° measurements from SeaWinds on QuikScat (QSCAT) are used in conjunction with the NSCAT and Seasat scatterometer (SASS) data to study the change since 1978