Subsidence map in 3d view

[Shadi1]

Coherence Masking

Let’s not mix things up. Masking before unwrapping helps to prevent unwrapping erros in areas of phase noise. Masking after unwrapping (e.g. of the final results) can help to prevent false interpretations of mathematically derived results (e.g. unrealistic displacement) They serve different purpose and depending on when you apply it, you might get different results. In the end it depends on the spatial distribution and proportion of low coherence areas.

I understand. I still notice a debate which is quite interesting, I am waiting for Berno to show us his results.

Although what genuinely confused me is that masking out low coherence would have been done to the unwrapped phase image before creating the displacement image, so that when we create the displacement image from the edited uwp. image, we would be able see the effect of removing low coherence on the displacement values.
Then from the latter we determine what the “x” value is, where there’s no surface changes expected, substract “x” from the uwp. image and then re-create the displacement map after the changes. Or simply substract that x value from the displacement image created earlier.

@ABraun

there’s a strong ramp in your image wich distorts the result massively.

Could you point out what the roughly phase ramp looks like? I have already searched this term in “Guidelines for SAR Interferometry Processing and Interpretation” but I couldn’t find clues. I’ve found this material
https://www.researchgate.net/publication/266913919_Slope_deformation_prior_to_Zhouqu_China_landslide_from_InSAR_time_series_analysis/figures?lo=1, however the ramp they have mentioned is quite different to what you have commented at.