Processing RADARSAT-2, TerraSAR-X, and ALOS 2 data

Hello, excuse me for a question:
How can I process RADARSAT-2, TerraSAR-X, and ALOS 2 COMPLEX data to derive backscattering coefficients? Is there one workflow that I can follow?
Thank you.

Is there one universal workflow that is valid for these SAR sensors?

yes, for all mentioned sensors, radiometric calibration (Menu > Radar > Radiometric > Calibration) will derive Sigma0 as the backscatter coefficient.
The only thing required is that you import yourd data correctly (Menu > File > Import > SAR > …) so that SNAP is able to recognize the sensor behind the data and apply the calibration accordingly.

Please also see here: What is sigma0


Thank you.

Hello, I have some SGF RadarSAT 2 HH images but when try to calibrate de image i need to choose between Almplitude_HH or Intensity_HH. what is the correct??

Generally, if you don’t select anything SNAP will chose the right input for you.

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Hello, in the topic: Radiometric & Geometric Correction Workflow, you gave the suggested workflow for Sentinel-1 SLC data as below:

Furthermore, as for SLC data of RADARSAT-2, TerraSAR-X, and ALOS 2, is above suggested workflow still suitable? Thanks.

no, Sentinel-1 IW is acquired in TOPS mode which requires the steps Deburst. This can be skipped for other sensors. Also the application of orbit files is currently limited to S1, ERS and ENVISAT, so you don’t need this as well.

So as for SLC data of RADARSAT-2, TerraSAR-X, and ALOS 2, I only need to apply the step 1, 4, 5, and 6?

basically yes. Filtering is always optional and depends on what you want to do with the data.

Thank you. I need the accurate backscattering coefficient to compare with my rough surface radar scattering model. So speckle filtering is necessary for me, right?

as long as your filter doesn’t enhance unwanted structures I think it is fine. But you need large areas to estimate the roughness in your image, because if they are too small, filtering significantly alters the roughness estimates.

Yes, reasonable. After the step 6 (Range Doppler Terrain Correction), the pixel value is the backscattering coefficient that I need?

actually you calibrate to Gamma0 in the Terrain Flattening step already. But the subsequent products contain it as well.

Thank you so much!