When i am processing Sentinel-1 SLC time series datasets, i encountered with a problem. First, i cropped the study area with 20km radius, and processed the time series with APS (by followed the manual ‘Demo on APS….’). Then i geocoded the result and export into Google earth, and the result is shown as attached. The result shows the deformation velocity and cumulative displacement of one PS point of interest.
Next, instead of estimating with a large area, i chose ‘small area processing’ and crop a rather smaller area, with 1km radius circle. Also, i have followed the manual. However, i get a result (same PS point) different from the APS method. Thus, i am wondering which one is more reliable? The reason for that.
there is a high number of factors that can cause the difference in the results. One of them is the reference point. Then one should check all options you used for processing. Also the outcome of the APS processing plays an important role on the final result. The topic is too broad to be treated here in a single answer. I suggest you to take a course on the subject. Best