however, here i have encountered several problems:
(1) i don’t know where the step i should choose "reference ponit’ in “pahse unwrap”, so that the deformation map has no reference point.
(2) and the deformaion map has some abnormal information, for example，here , the blue polygon represents a lake, but it actually has some strange deformation informations.
(3) finally, the deformation information here seems to have a northwest-southeast distribution trend. i don’t what reason cause it…
please ,can anybody help me?
Thank you sincerely
There has been a lake outburst here, which may lead to sedimentation around the lake.
So, I want to use InSAR to get the deformation around the lake.
and this is the coherence map:
For unwrapping,i use the DEFO/TOPO configuration.
Maybe, as @ABraun said, the baseline is too long to obtain the wrong deformation.
I am planning to do it with a shorter time baseline.
thanks very much.
finally, I still want to know about the reference point in “phase unwrap”/“deformation map”
I hope you can give me an answer.
Well, you cannot use the DEFO/TOPO, you should define only one.
As the unwrapped phase looks like a linear trend, I would suppose you have used TOPO (even if you probably applied the TopoPhaseRemoval on the interferogram computation because you wanted to compute the deformation (so you should apply TopoPhaseRemoval)
Please check and if I am right, change TOPO by DEFO and repeat the unwrapping with snaphu again.
Let us know.
PS: still, it looks a bit to me that you better apply another type of deformation technique such as SBAS or PSI instead of only DInSAR, as this technique is applicable for earthquakes and eruptions, but not deformation rates of mm/yr (or few cm/yr)
I’d like to ask you here about SBAS, since SNAP doesn’t support preparing data for SBAS, but in the same time the other part of SBAS, is supported by Stamps, what is the solution at the moment ?
Our colleague @thho gave good solution, but if you have other shortest way, especially to me at the moment, because I’m using VM.