Process for radiometric calibration (sigma0)

Microwave Toolbox
1

Hello all,
I’m working with KOMPSAT-5 level1 (SCS) images to make them sigma0 for comparison with other images.
As I know, the process for radiometric calibration is

  1. Apply Orbit File
  2. Radiometric Calibrate to sigma0
  3. multilooking and speckle filtering (optional)
  4. Terrain Correction (geocoding)

I have some questions about this process.

First, what is the “Radiometric Terrain Flattening” and when does it need? is it necessary?
I think it is needed when there is much topography, how can I decide it?

Second, if there is no orbit file, can I skip the apply orbit file stage?
When I tried to run the process, I got a message like this.

image
image717×203 22.9 KB

Finally, if I build a processing graph for the radiometric calibration, is it possible for me to apply it to other satellite images (TSX, CSK, etc) by changing only the input and output?

2

Orbit files are only provided for a selection of satellites. Kompsat does not require the application of orbit files, because it already has good orbit state vectors int he metadata.

Radiometric Terrain Flattening corrects radiometric distortions caused by the topography. Examples are given here: S1 radiometric correction

If the topography of your area is extreme and causes many of the slopes facing the sensor to be very bright in the radar image, you can consider applying terran flattening (using SRTM 1Sec at best)

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