Polarimetric decomposition of a stack

Hello everyone!

I want to generate polarimetric decomposition parameters of two Sentinel-1 SLC images acquired at different dates. Firstly, I split, applied orbit file, calibrated (saved as complex output format) and then I coregistered the two images using back-geocoding, I debursted the stack, generated the C2 polarimetric matrix and the H-Alpha dual polarimetric decomposition parameters. Unfortunately, The Entropy, Alpha and Anisotropy of the two images of the stack have the same statistical values. There is no change in all the 3 parameters for the two different dates. Does anyone know why the results are the same for images acquired at different dates???

is back-geocoding Coregistration a pre-requisite for SAR Polarimetric decomposition?? I followed the steps in the [PDF] Sentinel-1 SLC Preprocessing Workflow for Polarimetric Applications: A Generic Practice for Generating Dual-pol Covariance Matrix Elements in SNAP S-1 Toolbox | Semantic Scholar

Coregistration is not mandatory here. Probably the operator does not expect stacks as input.
I would process both dates separately and stack them after Terrain Correction (with collocation)

Thank you for your quick reply.