Noise & Holes SNAPHU

Microwave Toolbox
#1

Dear All

I have a question regarding the noise before and after the unwrapping done by SNAPHU.

Does anyone know how this particularly works? Why do I have a lot of noise before I perform
the export and after running the unwrapping, I get the absolute phase difference
but without any noise and no holes!

Can anyone help me with this case? Is SNAPHU interpolating by itself the noise/holes? If
yes, how is it performed?

The data I export is around 1.1GB (561MB the coherence and 561MB the Phase_ifg_srd) SNAPHU
needs around 3h. Its done directly on a Ubuntu Workstation (32GB ram & i7
5820K @ 3.30GHz)

I work with Sentinel-1A data sets in S6 Mode - Study site is La RĂ©union (Piton de la Fournaise)

Kind
regards,

Don

attachments:

Export to SNAPHU Set-Up

Snaphu_export.png648Ă—758 299 KB

Wrapped and Goldsteinfiltered Interferogram (toporemoval performed)

nov1_feb_0_2_0_Phase_ifg_srd__15Nov2015_19Feb2016_VH.png2001Ă—1269 1.04 MB

Unwrapped Absolute Phase (interferogram)

nov1_feb_0_2_0_Unw_Phase_ifg_15Nov2015_19Feb2016_VH.png2001Ă—1269 685 KB

#2

I’m getting similar bad results.

Is it possible to mask out some parts of the interferogram, for example based on coherence values, before export to SNAPHU?

#3

yes, this is possible in the band properties of the interferogram using the “valid pixel expression”.

unfortunately, this won’t affect the export of the image or the performance of snaphu.
But it can later be applied on the result to exclude these areas.

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