GRD multilook (number of looks)

What number of looks would be good for multilook processing fro IW GRD product?

depends on your application.
Why would you apply multi-looking on GRD products at all? It is actually designed for SLC products in the first place.
If you face a high amount of speckle a speckle filter would be the better choice.

Maybe this also helps you:


@ABraun, so, what operators are useful for Ground Range Detected products? (Thermal noise removal or Calibration)

you can apply both:

  1. Thermal noise removal
  2. Apply Orbit file
  3. Calibration to Beta0
  4. (Speckle filtering)
  5. Radiometric terrain flattening
  6. Range Doppler Terrain Correction

or (if you don’t have much topography)

  1. Thermal noise removal
  2. Apply Orbit file
  3. Calibration to Sigma0
  4. (Speckle filtering)
  5. Range Doppler Terrain Correction
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@ABraun, what about applying orbit file?

I’m using it for investigating some correlation between NDVI and backscatter on the agriculture fields.

If you want to analyze time-series a good co-registration of your images is needed. Applying Orbit files makes totally sense in this case. I updated the list above.
But if there are no radiometric distortions caused by the incidence angle and topographic variation you can skip the terrain flattening and directly calibrate to Sigma0.

@ABraun, thx for replying. I think I will done my bachelor’s degree project with your advice.