I am trying to create H-alpha occurrence planes in either PolSarPro, NEST, or PCI for Radar backscatter using Radarsat-2 data. I have successfully done it with UAVSAR in MapReady but unfortunately I can’t you the same method because MapReady does not support Rsat-2 data.

NEST is obsolete, our current general radar toolbox is S1TBX in SNAP

Please have a look at this tutorial: SAR Polarimetry and Analyses

The generation of H-alpha planes is described there in detail.