Backscatter change on fire scars in Siberian boreal forests in ENVISAT ASAR wide-swath images

The objective of this letter was to investigate the performance of the C-band Advanced Synthetic Aperture Radar (ASAR) instrument onboard the European ENVISAT satellite for mapping fire scars in boreal forest ecosystems. The Wide Swath Mode (WSM) of the cloud and haze-penetrating ASAR instrument with a spatial resolution of 150 m would be ideal to support nearly real-time fire monitoring and impact assessment over the vast and sparsely populated circumpolar forest belt. We found that: (1) the ASAR WSM backscatter signal was sensitive to fire disturbance; (2) the backscatter change correlated mainly with snow-melt and rainfall; and (3) the backscatter varied as a function of the incidence angle with a higher backscatter occurring at shallower incidence angles. The results suggest ASAR WSM data could be used to support operational fire impact monitoring in boreal forests of Siberia. Multitemporal datasets are required because environmental conditions strongly influence the backscatter signal.