Linear to/ from db in python SNAPPY

[gisrajan]

using tutorial given on website (http://remote-sensing.eu/preprocessing-of-sentinel-1-sar-data-via-snappy-python-module/) I am able to pre-process the sentinel 1 data. Now I want to convert liner to/ from db using SNAPPY and python.
How I will achieve this ??? I have searched internet but found no relevant results.

Kindly help me in this regard.

[mcvittal]

Hi Harshit,

Have you tried setting the parameter line in the provided link

parameters.put(‘outputImageScaleInDb’, False)

to

parameters.put(‘outputImageScaleInDb’, True)

[gisrajan]

Ohh… I have not noticed that. Thanks for pointing out.
I will try and update.

[Muesgen]

Hi,
i had the same problem and found now the solution. It is described in detail at this post:

outputImageScaleInDb in python snappy

Hi, I am doing the preprocessing on snappy in python for sentinel 1 data. I try to separate the output image in db scale. The ouptut image was in SIgmaBand scale and not in db Scale. So my question is, is the calibration step the correct step for saving the output image in Scale db or should i do this in another step or does anyone knows why it is not converting to db Scale. I have tried converting linear from/to db in the following calibration step: def do_calibration(source, polarization, po…

The solution is not to convert or save in the calibration step. You have to use the raster tool LinearToFromdB:

def convert_dB(source):
print(‘\converting to db…’)
parameters = HashMap()
parameters.put(‘sourceBands’, ‘Sigma0_VH,Sigma0_VV’)
output = GPF.createProduct(“LinearToFromdB”, parameters, source)
return output