Someone who knows the process for the area index burned in SNAP with Sentinel 2a
you can use the Normalized Burn Ratio BR for that. It uses near infrared and short-wave infrared and we already found it suitable for Sentinel-2 data.
The problem that this NBR is used for areas greater than 500 acres and compares before and after fire. And I want to use another method. Check this out: https://www.harrisgeospatial.com/docs/backgroundburnindices.html
You don’t necessarily need to compare before and after images, still its favourable. I think it is still valid for areas smaller than 500 acres as long the areas can be detected by the resolution of 60 meters.