Getting poorly unwrapped, weird interferograms from SNAPHU Unwrapping procedure

Hello STEP-Forum community!
I’m working on creating displacement maps from the Reykjanes Peninsula, Iceland, using Sentinel-1 SLC data.
I am able to create nice interferograms using the SAR images I have. To unwrap the interferograms, I use Snaphu Export, the Snaphu Unwrapping plugin and Snaphu Import. However, no matter what I do, the resulting “unwrapped interferogram” is very bad. I’ve tried performing my workflow for different timespans, and both 24 days and 12 day intervals. I’ve also tried using different coherence windows when making interferograms, and fourier transforms when doing the goldstein phase filtering. Could there be something wrong with the unwrapping algorithm?

My workflow is as follows:

Because the study area is not covered by one single SAR image, I need to download both a southern and northern SAR image and merge their subswaths/bursts together, which I do with splice assembly seemingly with no problems.

My interferograms usually look like this:

With a coherence like this:

BUT then the unwrapped phase looks nonsensical…


Would anyone know what kind of issue could be causing these unwrapped images to be so weird? I appreciate any help. Should anyone wish to try for themselves, an example of the data I use would be: