Take a look on the following pdf to be informed about the steps and the theory behind of Glacier velocity in SNAP.
to have more information: this method in SNAP is just useful to detect large displacement and it uses just intensity not phase information. this method doesn’t work to detect small displacement happened by landslide… look at the following link:
SNAP works well to detect Glacier Velocity but on sea-ice it doesn’t work.
as I forced to code to extract the displacement on sea-ice.
the method that most of the researchers use to extract sea-ice velocity is based on feature tracking and matching cross correlation…