Values of displacement from S1-A SLC pair

I ran the DinSAR workflow in SNAP and managed to get the output displacement map. This has been converted to vertical displacement. However, the values seem a little too big for displacement over a period of slightly over 10 days. Anyone knows if these values feasible? Am I doing something wrong?

After unwrap-> phase to displacement -> convert to vertical

What is the unit of the y-axis? Assuming your processing has been correct the result still contains the effect of the atmosphere, which can be large. Here’s a review-article about the issue:

As mentioned by mengdahl atmosphere may have considerable contribution.
I would propose, instead of converting directly to vertical, to generate a second interferogram from the other orbit (ascending or descending) for the same period and then combine asc & desc to calculate the true vertical motion.

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mengdahl and mfoumelis,

Thank you for that insight and the linking regarding the atmospheric contribution to INSAR derived displacements. I assume S1-A might not have the same asc/desc pass over the same period, so I guess the only option is from another satellite? Also, how can i combine the results from the asc and des passes? Will an averaging scheme do the job?

Any space-born SAR system has both ascending and descending orbits, for which acquisitions cannot be at exactly the same time. Selecting insar pairs from orbits close in time is a common practice, assuming no much change happened in between.
Please note that asc & desc insar measurements are done along different line-of-sight (LOS) and cannot be combined simply using averages. You need to geometrically combine considering acquisition geometries. There should be several related publications in literature.

I have some similar problems with the too big vertical displacements. Could you please mention some publications, or application method to combine asc/desc measurements?

Hi all

I did the interferogram for the San Francisco Bay (Oct, 6 to Dec, 05 2014), I don’t know wether is correct. Please, give me yours opinions about this!!!:blush:

Using the phase to displacement operator, is the resulting displacement positive towards satellite (i.e. uplift) or positive away from the satellite (i.e. increase in range)?