I am using the Sen2Cor 280 plugin with SNAP 8.0 for Atmospheric correction of Sentinel-2 Level-1C products and I have already executed it several times (with different options, for example for the parameter aerosol type: RURAL and MARITIME and AUTO) and I do not see significant differences in the results of the atmospheric correction of S2B Level-1C TOA to S2 Level-2A BOA (for Vietnam area). Just slight change in the histogram values (images below). From what I read in other posts on this forum the main question is related to the definition of the processing parameters (as the user “Maria” 1 had already requested help in this post).
S2B Level-1C TOA:
S2 Level-2A BOA:
Therefore, some users of this forum in other posts referred to use an xml configuration file for the atmospheric correction (“Ground Image Processing Parameters (GIPP)”) of an S2 L2A image of the study area. And apply this same configuration in the plugin, and I don’t need to define the parameters such as “Nb Threads”, “Median filter”, “Ozone” (image below).
By the way, where I can find a clear description and explanation of these parameters and mainly of the available classes, as we can see in the image below for the parameter “Ozone”.
I would also like to know what the options “Scene only”, “Cr Only” represents, because I don’t see any difference in the results.
So, I don’t have any S2 L2A reference image for that area of Vietnam… so I have to look for the parameterization of aerosol Optical Thickness, Water Vapor Retrieval, Cirrus Correction, Surface Reflectance Retrieval (as described in the Sen2Cor Configuration and User Manual, url: Sen2Cor Configuration and User Manual. The problem is how to define the thresholds. That’s where I want to find answers. I don’t think this has to be through the Trial & Error method.
Thank you very much,