Odd L1C/L2A Results


Howdy All,

I’m having some peculiar issues with Sentinel 2 data. I’ve downloaded two coterminous tiles (one L1C tile from EarthExplorer and one L1C/L2A tile from AWS) taken at the same time and date. I have done this to verify that my methods of atmospheric correction (ESA’s sen2cor tool) are valid and give me precisely what I would get from simply downloading AWS’ L2A product. The tile ID follows: S2B_MSIL1C_20190113T181719_N0207_R084_T12TWR_20190113T200650

The issue is, it doesn’t produce identical results. When I go to calculate NDVI from my bottom-of-atmosphere product, I get different values when using AWS’ L2A versus the L2A I produced using sen2cor.

I’ve done a little research on this and found reference to a “pilot” introduced to ESA’s L2A_GIPP process in 2018. There seems to be a version 2.11 floating around out there, while the process in sen2cor (2.07) produces “L2Ap” instead of “L2A”

My question is: Does anyone know why an identical atmospheric processing chain would produce dissimilar results? Thanks in advance!


Please, see How to reach Sentinel L2 from L1C using sen2cor?


Sorry for the delayed response - we’ve been snowed in here in Chicago and I’m just getting back online today. But thank you obarrilero, this is extremely helpful knowledge!