Scale S1 data linearly from float32 power values to uint16

GriffinBabe commented 3 months ago

Optimization of memory by scaling sentinel-1 power values to uint16

[x] Perform data scaling in the data fetching phase
[x] Provide utils to retrieve data in power values or in dB within the Feature Computers

GriffinBabe commented 3 months ago

Jeroen Dries I pushed a fix here based on what was done for the cropclass project. This scaling assumes that the sentinel-1 GRD values are in power values. Could you confirm that this is always the case after passing through backscatter computation by orfeo? https://github.com/Open-EO/openeo-gfmap/blob/8483c37727b593f8f21da567327f22224ceec32d/src/openeo_gfmap/fetching/s1.py#L119-L128

There is also this differentiation with a field isCreo. Is the CDSE backend considered as creo as it is using creodias collections, or is this unrelated and I can just ignore the additional check? https://git.vito.be/projects/APPL/repos/cropclass/browse/src/cropclass/openeo/preprocessing.py#89

jdries commented 3 months ago

the additional check in isCreo is still relevant normally. Orfeo has not yet received a fix for these low values as far as I know. sar_backscatter indeed always returns power values

Open-EO / openeo-gfmap

Scale S1 data linearly from float32 power values to uint16 #70