Initial Observations of Radarsat Imagery at Fire-Disturbed Sites in Interior Alaska

Previous research has shown that wet soil conditions found at fire-disturbed sites in the boreal region produce bright backscatter on ERS imagery compared with the surrounding unburned forest. ERS-2 and Radarsat imagery collected at two incidence angles is presented and compared. Measured brightness is also compared to backscatter model results. It is found that Radarsat imagery collected at incidence angles similar to ERS-2 result in a similar, relatively bright backscatter from the fires scar, while backscatter from Radarsat image collected at a higher incidence angle is relatively dark. Model results confirm that incidence angle is critical in determining the relative brightness of the backscatter from fire scars. These results have implications when looking at broad-coverage SAR images which span a large range of incidence angles from near to far range.