Hello Dr. @EJFielding Hope you are doing fine. I would like to take a few moments of your precious time to ask about the derivation of east and up components in a mountainous terrain particularly higher Himalayas. Do you think it will not be a good decomposition of LOS in such a variable terrain where slope, aspect and decoherence have a huge impact on the InSAR signal. I have created time series of both ascending and descending mode, but it looks very difficult to combine them to derive LOS components. There is also the northward velocity of Indian plate (arc normal) which is insensitive to the InSAR signal. Do you think it is pragmatic to use time-series InSAR to derive deformation components in the region especially PSI.
Hello,
You are correct that the regular InSAR from ascending and descending tracks are insensitive to the north component. In the Himalayas and other places, the north component may be the largest tectonic motion. You cannot recover three components of displacement from two LOS measurements. You would have to assume the north component or measure it another way.
The steep slopes will cause a loss of coherence and you may find that the ascending track has good coherence on one side of a mountain and the descending track has good coherence on the other side so there is no overlap in coverage. This will make it difficult to estimate even two components of displacement.
Another problem with measuring the tectonic motion is that there are many landslides and other local slope displacements in the steep terrain. This means it can be difficult to average over a large area.
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@asrar_sultan Could you please publish here the equations you use for the conversion?
From SNAP one can get Up and East component, but for North one can’t get much