NovaSAR gamma naught

I have downloaded some NovaSAR data and would like to calibrate it to Gamma0. Does anyone know if this is possible?

I understand from the documentation about NovaSAR that the images are provided as fully radiometrically calibrated. This is evident in the multilook detected data I have downloaded which opens as Sigma0_Intensity or Beta0_Intensity. If I try to calibrate I get the “NovaSAR _01 is not currently supported for calibration” error and if I try and terrain correct with the “Apply radiometric normalisation” box ticked I get the error saying “radiometric normalisation currently is not available for NovaSAR”. So my first question is whether this is even theoretically possible? I realise SNAP does not support it but can you change between different types of radiometric calibration without having the uncalibrated data?

I have also found a couple of NovaSAR CEOS-ARD (analysis ready data) products. These have supposedly been subject to radiometric terrain correction in Gamma0. But when I try to open them in SNAP I get the “cannot be opened” error. Has anyone else come across this data format? Is there another way to open it in SNAP?

Thank you,
Frances