Sentinel 2 product upgrade integration

Hi @gunjan,
it depends how you are accessing the data:

• if you are using Sentinel Hub, then the new data is harmonized to the old data (by default), whereas you can choose to get original value, if you want so (more here)
• if you are accessing the data directly in AWS S3, then the values have essentially changed and you need to handle this by yourself, The data on AWS S3 are exactly the same as the one produces by ESA/Copernicus.

Not sure which concerns you have in mind.

Best,
Grega

Hi Grega,

What do you mean by - “values have essentially changed and you need to handle this by yourself” - will level-2 surface reflectance values be different before and after the change? will it affect let’s say NDVI values?

Also, will the change be backpropagated for past images as well?

Thanks

Yes indeed, surface reflectance is changed. Not sure how exactly this will impact NDVI, would have to do a few experiments.
There is no plan to propagate this to past images, so you need to handle this dynamically.

As mentioned, if you are using Sentinel Hub, you should not notice a difference.

Hi @gmilcinski - I’m trying to figure out how to handle manually the changes in Sentinel-2 Level-2A.
Correct me if I’m wrong but according to this doc- in order to get L2A BOA reflectance values, I should use this formula:
L2A_BOAi = (L2A_DNi + BOA_ADD_OFFSETi) / QUANTIFICATION_VALUEi

To make sure these values BOA_ADD_OFFSET and QUANTIFICATION_VALUE appear in the
MTD_MSIL2A.xml:

So if I download Sentinel-2 Level-2A and if the value of a specific pixel is L2A_DNi=1452, then the BOA reflectance should be converted to - (1452-1000)/10000 = 0.0452?

Also, are BOA_ADD_OFFSET and QUANTIFICATION_VALUE constant or they might change?

Thanks

@gmilcinski any updates on how this change affects the NDVI? I’m trying to correct the values for all bands according to the formula above but the resulting NDVI values seem higher than expected (compared with the eo-browser).