Phase unwrapping and low coherence

Microwave Toolbox Interferometry
2

Can you please share an image of the interferogram before unwrapping as well?

In general, unwrapping was successful when the cyclic patterns turned into absolute values. The only patterns which are left should be those which were already visible in the interferogram and can be related to surface motion (when topographic phase was removed) or terrain (without topographic phase removal). Whenever there are large trends superimposing the unwrapped phase (e.g. ramps from left to right) chances are high that these are not actual changes but rather unwrapping errors resulting from noisy phase areas.

Examples for good results

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Source: Theory and prac-ce of phase unwrapping

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Source: A new method of weighted choice in InSAR Least Squares unwrapping

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Source: Braun 2021 Retrieval of digital elevation models from Sentinel-1 radar data - open applications, techniques and limitations

Examples for bad results

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Source: (PDF) Extracting Digital Elevation Model (DEM) from SENTINEL-1 Satellite Imagery: Case Study a Part of Cameron Highlands, Pahang, Malaysia

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Souce: Displacement from Sentinel1 - #35 by chronomanz

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Source: Some problems occurred interferogram formation!

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Source: Problem with the final steps of interferometry

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