Windthrow storm damages on the Alps

A wide wind storm damaged forest areas in eastern areas, most affected areas are most probably on Italian side. We are trying to have a first assessment of damaged areas with Sentinel1

We have a pre event and a post event image. Any suggestions for creating a disturbance map (a map showing the area with trees on the ground). Since there is a change in vegetation height should we have to use an interpherometric approach or just a change ratio?
Can we do the analysis even if the image after the event was taken in rainy condition and the pre-event not ?

repeat-pass interferometry doesn’t work very well over vegetation because of signal decorrelation. So I would just calibrate and terrain correct both images and compare the decrease of backscatter intensity.
Just make sure both images are taken from the same orbit/track to reduce effects from different looking angles.

Thank you @ABraun we are trying that way… in SNAP for pre-processing:
1 Applying orbit file
2 radiometric calibrate
3 radiometric terrain flattening
Does this sound reasonable?

absolutely. Just keep in mind that slopes affected by foreshortening cannot ‘repaired’ by terrain flattening and correction. Maybe you find a path/track which favours your study area.

coregistration needed in your experience?

It is certainly worth looking at the 6-day coherence from ascending and descending passes.