Questions about numTriNonzeroIntAmbiguity and temporalCoherence

[david-ncu2019]

Dear authors of MintPy,

First, I would like to thank you all for creating such a great program for InSAR time-series analysis. In particular, the integration of MintPy with HYP3 has significantly sped up the processing time and saved a considerable amount of storage space.

However, during usage, I have encountered some issues that I am unable to interpret on my own. Below, I will present one of these issues and hope to receive suggestions from the authors or other users who may have encountered the same problem.

My input consists of ascending Sentinel-1 interferograms obtained from the HYP3 service (https://hyp3-docs.asf.alaska.edu/using/vertex/). My goal is to observe the development of land subsidence patterns in my study area.

After selecting the reference point, which is located far from the subsiding regions, I performed quick_overview. The numTriNonzeroIntAmbiguity output showed the following patterns:

Since the output from the HYP3 service did not contain .conncomp files, phase unwrapping error correction was not available during my processing. I then proceeded to invert_network, and below are the patterns from temporalCoherence.h5:

As you can see, the temporal coherence values are separated into distinct zones, almost as if a "wall" is preventing the values from being smoothly continuous across the entire region.

Meanwhile, when I processed the descending interferograms obtained from the hyp3-isce2 workflow (https://github.com/ASFHyP3/hyp3-isce2) with insar_tops_burst, this issue did not appear. I wonder if this issue is caused by the HYP3 Vertex service and how I can correct it.

[ditafaith]

Hi @david-ncu2019
In my poor understanding, burst data can be better than gamma products due to mostly all images overlapping.
I just realized that mintpy can process burst. Is there any reference can be followed?

[david-ncu2019]

Hi @ditafaith ,

Thanks for your response.

To clarify, are you asking about the tutorials for processing the products of insar_tops_burst using MintPy?

[ditafaith]

Yes, it seems interest @david-ncu2019

[david-ncu2019]

Hi @ditafaith ,

You can find the tutorials here: https://hyp3-docs.asf.alaska.edu/tutorials/

[ditafaith]

That's great. Thanks @david-ncu2019