I processed 13 S1A images to map the deformation due to an earthquake and possible movements before/after. I followed a tutorial for multi-temporal analysis. As I suppose that the deformation is non-linear, I used the corresponding parameters suggested in the tutorial.
I cannot see any movements on the displacement map, on the other hand the displacement is clear on the interferogram calculated form the two images right before and after the earthquake.
Could you please help me what am I doing wrong? I also tested the APS removal, but it did not help.
yours is a particularly complex case.
Non-linear movements can be well estimated with the smart option that you selected. The smart option in fact applies a low pass filter in time. However, given the more degrees of freedom, the smart option requires more images than usual to be robust: 13 is a too low number.
In any case, an earthquake is not a low pass signal. So, the smart option is not a proper choice.
There would be many more considerations to do but this is not the proper place to discuss such a case. This work requires some close attention. I suggest we continue the discussion by different means.