I’m wondering if anyone can explain to me why I would get different wind field estimates using the SNAP toolbox and sentinel-1 imagery depending on whether I am looking at the cross polarized image vs the co-polarized image? Viewing the results from running the wind field estimate feature extraction yields quite different values for VV vs VH.
Thanks in advance for helping.
I think this is because some waves alter the polarization of the sar wave due to their orientation (VH), size or shape while most of them remain HH. This inevitably leads to different results.
The principle underlying the wind field module is presented here:
As they were tested on co-polarization ERS data I think the VV is the better choice.
In the following source, an underestimation is also reported for cross-polarized data:
I would intuitively stick to the VV data but a short literature review clould help finding evidence for better results of co-pol data over cross-pol data.