Confusing Band maths result - NBR maximum is over +1

Hi there,

I’m wondering about the results of my NBR: the Maximum is +1.37 (see picture below),

and as we all know the NBR (like any other normalized difference index) should be between -1 and 1…

It’s super weird because I already calculated the NBR for 1992 and everything was fine:

For background information:

  1. I’m using Landsat Data, because I’m interested in the years 1992 and 2003. I decided for the Coll. 2 Lvl. 2 products because I’m relatively new to remote sensing and wanted to make sure that I don’t do anything wrong with the preprocessing steps.

  2. I’m only interested on forests, so I’m running my indices (also calculated NDVI and NDMI) on a self created forest mask. I already tried out if this mask was somehow the reason for fail – it wasn’t. I also ran the calculation for the hole image scene to find out if it’s correct there - it wasn’t neither!

Now to my big confusion: If I do a dark substraction before, the min-max. values are between -1 and 1 BUT im using Lvl. 2.2 products! I’m sure that I should definitely not do this (it’s like a double atmospheric correction and “falsification” of the data, I guess) – so what is my mistake?? What can I do?

I’m glad for any help, tips or advices!


P.S. in case that I didn’t post my question in the correct section, sorry for that, I’ll change it asap!

Found the reason: it’s due to the clouds in the scene!