How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP

Dear all,
Here is, i explaining my step and attaching log files.
I followed this steps.
I have used python v3 for run py files.

According below comments, pscands.* files size shouldn’t be 0. But my result 0. Anyone take me any suggestion thanks.


coreg_ifg_proc_stdout.log (20.5 KB) export_proc_stdout.log (15.3 KB) ps_parms_initial.log (2.6 KB) split_proc_stdout.log (74.2 KB) STAMPS.log (3.4 KB)


I have had this exact same error when i started processing.
In my case i had accidentally left a ascending file in my descending processing folder.
other options are:
bad ifgs or empty raw images.

You can check this in the LOG of mt_prep_snap.
in the LOG you will see a number for ammount of zero pixels and the mean amplitude.
if the mean amplitude is low or you have to many zero pixels something is wrong.
check and/or delete this ifg from the processing and start again.
This will probably saolve the error (which is related to the ciphers in the array and the matrix dimension).


Yes, i have checked 10 times :smile:
All mean amplitude was 34 or higher.

2nd thing i did was reprocess all my ifgs.
I used Snap2StaMPS so this was not a big issue for me.
That could help, if not i have no clue.

I am processing 24 images but in two sets of 12 images, but when the DEBURST step is about to end, this problem occurs.

Can somebody help me,

Similar Error, GLException is discussed in here,

Source of the post

In case this doesn’t solve your problem, please give more details about the steps you did, it could give more details to help you.

Normally snap2stamps does not work with Python 3. In the manual I recommended Python 2.7

Still…which stamps version you used? 4.1b? Or earlier version?

The more information you share with us the easier for us to help you

I have used 4.1b, i saw code inside of py files, there is no big difference working with python3 i have changed just print command (v2.7 print message v3 print (message) ).

I know about the differences, but as said you said nothing about those changes you made. Good. One source of error less

Regarding your error. Please provide more information… otherwise it is difficult for us to identify your problem

Best regards

Dear Mdelgado, I’m just starting to use snap to prepare images for stamps.
I followed the workflow provided by PSI USING StaMPS.docx (185.1 KB), so doing all the steps with no script.
But when I skip to matlab to run the mt_prep_gamma_snap(changed) (6.4 KB) it doesn’t find the slc.par files…no INSAR_MASTER_date folder has been created actually.

I only got the four folder diff0\geo\dem\rslc.

In wich phase something was wrong in your opinion?
thank you so much

the script mentioned in the word file (mt_prep_gamma_snap_changed) is no longer up-to-date.

You find the latest version of StaMPS here:
You can then use the mt_prep_snap command to process the data generated by the StaMPS export of SNAP.

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Still… it also depends how and where you have launch the command.
Without this info we cannot assess exactly which the reason it, but just guess…

So we hope to be guessing properly.

Let us know

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I am trying to process StaMPS export and I wanted to check if I need to process radiometric calibration on the SLC images before creating the stack of coregistred images?
Thank you!

No need to apply both calibration or speckle filter to the SLC’s image,

Please take a look at this post,

Source of the post

Hi all, please, somebody could tell me how I can export the figure to .kmz format???

Thanks in advance

Within the StaMPS manual it’s mentioned how to export to kml,

StaMPS/MTI Manual Version 4.1b


Later on you could convert the kml file to kmz,


Hi all,

When I type ps_plot(‘v-d’,-1) obtain
Error using load
Unable to read file ‘./phuw1’. No such file or directory
Error in ps_plot (line 912)

Why this? the phuw file is obtained after of the unwrapping? I ought unwrap first???

Thanks for advance

Does this code work?


If Not, I think you didn’t properly navigate to the file direction.

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Hi @falahfakhri and all

Please, tell me if my folder general of data is complete!!! I have a problem of orden of my files… I am trying of ordered this!!!..

Thanks for advance

looks alright to me, but mostly dependent of the content of all the files and folders.
Just a recommendation: Leave the folder exported from SNAP (dem, diff, geo, rslc) as it is and run mt_prep_snap in a different/new directory, so all new files are written there separately. This helps you to clean up in case you want to start again without having to repeat the StaMPS export. Basically, all other files besides the four directories are required by Matlab (the textfiles and the PATCH folders).