I’m trying to determinate surficial deformation related to a landslide about 1x1 km in size (see S2 images below). There was a movement triggered by an earthquake, the idea is to determinate the occurred displacement. I have two S1 images from before and after the movement occurred.
I have selected one burst from each image. The phase product from both images is below:
And the unwrapped phase product as follow:
For some reason that I ignore, the values I’m getting in the displacement product are too low, I was expecting to see at least +/- 1 m displacement, but the histogram just show values from -0.06 to 0. Any clue of what I’m doing wrong?
This exceeds the range which can be predicted by DInSAR from a single image pair. Please remember that Sentinel-1 has a wavelength of 5.5 cm and displacements beyond that will be ambiguous.
Furthermore, if you select one image before and one after the landslide, the area of the landslide can suffer from strong decorrelation because the scattering mechanisms change.
These aspects are summarized here: I want to measure landslides using DInSAR
Yet, there are studies which use DInSAR for landslides, but these have differnent ways dealing with decorrelation.
Thanks a lot Andreas,
Do you have any clue why I’m having just negative deformation, and the is not positives values?
if you ask me, none of the values can be trusted because of the reasons mentioned above.
I see. Do you think would be valid to use the coherence product to map the boundary of the landslide?
@cristian.orellana.ca I’d suggest reading the EGMS “European Ground Motion Service: Service Implementation Plan and Product Specification Document” and pay attention to especially table 3.4.