DEM generation

[ABraun]

I don’t think you can extract urban altitudes with S1 repeat pass interferometry in a good quality.
However, the ramp should not exist, you’re right.

Which data did you use? Mode / dates of acquisition?

Maybe this gives you some more information about phase evaluation and atmospheric effects:

Some explanations about concepts of fringes of interferogram and coherence

Atmospheric phase cannot be removed by a SNAP module as it cannot be modeled, like flat earth phase or topographic phase, for example. If you would make reference measurements of water vapor or have dense time-series data (example) you could theoretically remove the atmospherical phase distortions. This is advanced however (example 2). You calculate an interferogram between a pair of images. It shows you the differences between both images regarding their single phase signal. As the satelli…