DC to reflectance

Dear all,
I would like to export the S2 L1C image into a netcdf file containing the physical values of every band (in reflectance unit, for instance). However, I’m stuck with integer numbers. How can I convert the DC into scaled values before exporting?
Many thanks,
Tristan

Hi
I think you can use a simple bandmath like “B2/1000” and save as floating point data.

Please have a look at the algorithm document “https://sentinel.esa.int/web/sentinel/technical-guides/sentinel-2-msi/level-1c/algorithm”. Reflectance, often between 0 and 1, is converted into integer values, in order to preserve the dynamic range of the data by applying a fixed coefficient (1000 by default).

Regards
Ralf

Hello,
Everything was well done!
Thanks for your help,
Tristan

Be aware that the quantization of reflectance values in L1C product will change in future products. Reflectances will be coded in the [0, 10000] range instead of the actual [0 1000] that you can observe in current products on scihub.

A metadata value gives you this information in :

Level-1C_User_Product/General_Info/Product_Image_Characteristics/QUANTIFICATION_VALUE