Sentinel 2B Level 1 C (TOA) Reflectance to at sensor Radiance conversion


I converted Ref to Rad using SNAP. But Output unit was giving null value. I did it manually by following the SNAP algorithm. Both outputs were quit same. But I’m confused with the units. Also confused with quantification value. whether to quantified before algorithm or quantification is included in the algorithm?
Please clarify. Thanks

I think you get this result when you use directly the jp2 files and write it to e.g. GeoTiff, right?
When You use the jp2 files you need to apply the quantification value. It doesn’t matter when you do it. Because it is just a scaling. If you use the full Sentinel-2 product by opening the MTD_MSIL1C.xml file the quantification value is already applied to the data.

The unit value you see is caused by the fact that you use the jp2 files. Usually, the unit is copied from the source to the target. Which is not correct. I’ve created an issue for this (SIITBX-297).
If I do the conversion on a Sentinel-2 product I get this result: