ESA published an article on their web-site concerning the detection of wildfires in Australia with Sentinel-1 data.
(Fire Information for Resource Management Systems) from Nasa with Sentinel-1 SAR data.

Fire spreading in Australia

Clouds and smoke influence the optical signal. Sentinel-1 SAR can measure the changes independently.
Many thanks for the editorial support to Mali Cecere.
Have a look at the web-site of ESA: Copernicus Sentinel-1 delivers change maps for wildfires