Interferogram generation problem (purple image)

the green color is just some remaining pixels where only one of both rasters is covered. No interferogram can be computed here. You can remove it in the end (creating a subset after terrain correction). I would leave it by now and don’t recommend subsetting the interferogram before the unwrapping because this caused issues in some cases.

@ABraun These exact green pixels are the ones bringing the problems in step1 of stamps!!
Even if this is now solved in my script, it would be nice if the developers could make that those pixels are not saved/exported after doing the StaMPS/PSI export.

Still, I have solved it and I have shared my script with the community. Here again!ps_load_initial_gamma.m (7.2 KB)


I see, thank you for clarification.
I supposed the aim here was traditional InSAR and that is why I suggested to neglect them. But you’re still right, they are unnecessary and in some cases even harmful.

Please can You help with step by step Interferogram generation. I have tried to follow this video ( but afer few minutes these are the error messages

I have followed your steps. I have this error message

Thank You for your help

Fils Cesar

GC overhead exceeded means that your computer ran out of memory. You probably need more RAM.

do you mean the first image and the image after geocoding?

no the master and slave image after coregistration.

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I imported 2 sentenil-1a slc format in iw mode images to SNAP for subsidence measurement. after interfrogram production, coherence will be like this picture and has consecutive black stripes. could anyone tell me what is the cause of this problem and how can I fix it?

was the coregistration successful? You can create an RGB image to check the quality of backscatter of both dates.

thanks for your answer. this is the RGB image after coregistration. this is not my speciality, my major is geology. in your opinion, is there any problem with coregistration?

This looks alright so far.

Can you please run the coherence operator separately (not the one within the interferogram generation) and compare the results?

yes, sure. Do you mean the coherence estimation from this path: interferometric - products - coherence estimation?

yes, at best with the standard settings

Just to go sure: I meant to run it after BackGeocoding and ESD

I did it but the result is same as coherence within the interferogram production.

Is this repeatable? What happens when you run all steps again from the beginning?

Have you tried different dates for a test?

I didn’t repeat for these dates, but I tried different dates and there wasn’t any problem.

how does the coherence look before ESD?

Interesting, the co-registation has been “successful” to a degree, otherwise there would be only spurious coherence and the phase-image would be only noise. Clearly something went wrong somewhere on the way.

I ran coherence estimation before ESD and the result is the same as before. It is better I run all steps from the beginning, as the results show there may be a problem with the previous steps.