I have created a displacement map from two pairs of Descending SAR images for an AOI. I have single pixel gives the amount of displacement with minus or plus sign.
I do not have any stable reference point from GNSS instrument in the AOI at present time, but I only know some areas have not been moved or displaced. I chose a point from that area and subtracted from the whole phase map.
In this case, without visiting the site, how I know the area of subsidence from uplift?
Many thanks in advance