I’m experimenting with S-1 Wave Mode vignettes and I would like to apply radiometric calibration. As WM is not recongnized by the calibration operator, I try to perform the calibration according to ( S1-Radiometric-Calibration-V1.0.pdf (328.1 KB) attachment), ie. apply the formula sigma_naught = DN^2/Asigma^2 to every sigma_naught value, for every line, provided in the .xml calibration metadata file.
My question is, is there an efficient way to do this inside SNAP? If not, is there a best-practice to apply this operation? I would like to continue working with the calibrated product in SNAP. I thought of creating two vectors in python and doing the computation, but how can I re-introduce the result in the WM product and continue the processing?
Hi Val! I must say you wrote a great doubt and I believe I share it with you.
Let me add another aspects that concerns me now regarding Wave Mode Level 1 product:
Do we have to apply scaling, range spreading loss and elevation antenna pattern corrections manually?
I could not do any of this in SNAP also. Perhaps this is my fault.
Anyway I would like to bring two ideas for you:
Have you tried to use band math feature? I believe it will allow you to make the calculation you mentioned inside SNAP.
I believe you could also export your product as NetCDF (from SNAP). Then you will be able to work it with python. You may work on your product using python and save it in a new NetCDF file (calibrated) using the same file format/structure and then open it with SNAP for further processing.
Well, those are only ideas. I don’t know if those approaches will work.