I think I found the reason for data degradation of scenes from Northern territories.
- The latitude of scenes is higher 70 degrees North.
- Dates of scenes I use, are of deep autmn (September)
- Time of sensing is morning
In fact, that time is almost nightfall …
As the result, Source L1C data in both B01 and B02 bands have low intensities, and quite narrow dynamic range. Sure, low intensities are in all bands, but only B01 and B02 degraded after Sen2Cor processing.
Band 01 L1C Source View:
See the full range of B01 is 0.0001-0.216 and actual data range is 0.14-0.18
The result after Sen2Cor B01 Processing View:
See the histogram. About half part has been cut.
To resolve the problem I multiplied both B01 and B02 source bands by 2. Just to increase intensities and broaden the dynamic range.
The result of Sen2Cor B01 processing after multiplyin source data:
As you can see, data is not degraded.
I think it is the not right way to escape of data degradation.
But I think that the reason is low L1C source data intensities.
And probably either some round operations or some integer operations occur within Sen2Cor processing flow.
I hope it can be corrected, if so …