SARCalibration How LUT choice should be interpreted?

Hi,

In the Description section of SARCalibration it is written that:
“This application allows computing Sigma Naught”
And for calculation of this Sigma Naught there it is said that there are 4 LUT choices available at product metadata : [sigma,gamma,beta,DN]

Questions:

  1. The calibrated data is “SigmaNaught” no matter which LUT we use? or depending on the selected LUT, we have to call the output(calibrated) data, GammaNaught, BetaNaught etc. ?

  2. what are the interpretations of choosing one of the 4 available look-up-tables for production of Calibrated data ?

As a test case I chose a sentinel-1 IW GRD product and calibrated the HV-polarization product 4 times with each one of these options then for the output product I ploted the histogram of the calibrated product. The respective histograms practically look the same. Also the statistics (mean, median, std, min, max) are also very close to each other!

I would appreciate any comment on this

https://www.researchgate.net/post/What_is_radiometric_calibration_of_Synthetic_Aperture_Radar_Data