I need the RADIANCE for my equaiton and I know that Level1C of sentinel 2 is reflectance. So I need to divide the DN values in my Sentinel 2 MSIL1C to Quantification value to get the Radiance. In the metadata of my image I searched for the Quantification Value and I got this:
I got confused by this “none” in the metadata! Does it mean that the quantification value is 0.988311824548184 and I need to divide my image to this number to get radiance?
Thanks a lot for your reply in advance
L1C product has TOA reflectance values. The quantification value from the metadata is used just to obtain these reflectances from DNs (hence the unit “none”). If you seek for radiances, you can use the Reflectance2Radiance processor from SNAP/S2TBX (in the Optical section).
Hi thanks do you mean Optical>> Thematic Land Processing >> Reflactance to Radiance? I put the band I want in this module. It asks me for solar incidence angle, U and solar irradiance IF IT IS NOT SENTINEL! But it s sentinel and it does not recognize it. I looked at the metadata: Can this solar irradiance be something like 1512.79 and U is the one I mentioned in my initial question 0.988311824548184 ?? I cannot find incidence angle in the meta data!!! It does not run without this information but I think it should technically know this values. What is wrong with my process you think? Any idea would be greatly appreciated.
Hi why when I want to use Reflectance to Radiance in SNAP (Thematic land processing) and I use Sentinel 2 band 3 as my input. It asks me incidence angle, solar irradiance and U? What are these? Isn’t it supposed to recognize them itself? I couldn’t find them iin metadata!Is there any other way to convert Sentinel 2 Level C1 (which is reflectance) to Radiance?
Please help me resolving this
Thanks in advance