I’m trying (after a fairly long break of not using SNAP) to perform some DInSAR for the first time (following this guide), and I’m running into an issue where even though I’ve checked the option for removing topographic phase in the “Interferogram Formation” operator, once I go through unwrapping and converting to displacement, I still see a color gradient that somewhat matches the surrounding terrain (smaller features have been removed, but the larger scale is still here), but the scale is very small (i.e. the difference between the white and blue regions is on the order of millimeters, not meters)
Here’s an example of the data for a measurement in Phoenix:
This leads me to two questions:
- Is this normal to see this?
- If it is normal, how do I differentiate between this and actual ground displacement?