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

Hi @kouhartsiouk @Fikretjfm

I have a problem during the processing final, the process stopped for 20170409, and when I check the folder .rslc I can see the archive 20170409 duplicate, someone had the same problem?

Thanks for advance

Dear Katherine,
Thank you for your reply, I also notice that almost all the PSs points I get are located in urban area, and get only few PSs in rural area. It’s a shortage for StaMPS PS method, and can hope SB method to improve it.
But it seems that the implemention of SBAS export in SNAP have to wait a long time…:joy:
All the best,

maybe the file was still in use by another program? Does it always happen with that date?

hi ,
have you tried to delete one of them? I havent faced such a this error.

Thank you for the test-report Fei!


in the last weeks I tried using the SNAP-StaMPS workflow for PS analysis. I found this thread which was incredible helpful. I summarized…again…the workflow, I found the summaries and hints given were great @katherine, @bayzidul, @FeiLiu, @ABraun. But latest updates of SNAP and the amount of steps are confusing, gathering and following all hints given to reach the goal.

Maybe some of you which have experience in the workflow might have a look at the summary to help improving it.

Furthermore I would really like to do all the steps with a test dataset to retrieve a valid displacement map and write a comprehensible tutorial. I do not have data for validation, hence I am just starting using interferometry. Therefore I do not know if outputs produced are valid or not…maybe someone can help me to do this, just write me a message here.

To read the summary, download the .html here and open it in your browser.
Edit: The file is no longer available, please check the instructions here: About the StaMPS category

Thank you :slight_smile:


Wow, thank you for compiling all this and of course thanks for sharing it here!

That’s great, Thorsten. We should add this to our tutorials section when it has a good status and if you allow. But then it should be at a better place where we can easier link to.
Unfortunately, I can’t help with the validation. I have no knowledge of the domain.

Hi @thho

This is an outstanding work you have done. The document is a great support to the enthusiasts. Thank you so much.
The validation is a tricky process, you can either validate your result with GPS or Levelling based reference data or you can use another software to compare. There is a lot of papers on this that might help you.

Thank you

Hi all, I have used SNAP6, and
@katherine 's and @FeiLiu 's changed script and followed the lastest workflow of @FeiLiu. I can successfully run the SNAP and StaMPS and get the final result.
However I found a new problem about DEM data from SNAP exported. It seems this DEM cannot be recognized and cannot be used by StaMPS. I added the elevation data in SNAP and can find the DEM file at the dem folder in the exported folder.
I found this problem, because of:

  1. When I try to used “ps_plot(‘v’,2)” to plot a shaded relief topo as background, StaMPS returned an error “Cannot find in this directory, parent or grandparent”
  2. When I try to used “ps_plot(‘v-a’)” to plot a result that minus topo-correlated atmosphere, StaMPS returned an error “Unable to read file ‘./tca2’: no such file or directory.”
  3. I have compared the results of “ps_plot(‘v-d’)” and “ps_plot(‘v’)”. They are exactly the same.
    It would be appreciated if anyone could help me.

Thanks for your kind replies @ABraun, @marpet and @bayzidul!

It would be great to see the final result in the tutorial section. The domain I used to store the document allows me to update it frequently. I want to avoid numerous links to different versions but one source at all. In the end a final result can easily be stored wherever it fits best.

Concerning validation, I will dive in some literature and maybe there is a SFM product which could help me…I will keep you on track. But if someone might help me, you are welcome!

1 Like

Help from user thho


You can look for him in the forums

Hi YuL,
There does exist some omissions in processing, but they don’t influence final result.

  1. It because StaMPS does’t generate it’s own DEM file when processing, but it doesn’t mean export DEM file cannot be recognized, you can generate it by yourself if you want.
  2. It because StaMPS cannot find atmosphere file ‘./tca2’, I don’t know how to generate this file, either, it seems generated by other programs, maybe TRAIN?
    3)They looks same, but they are not, they calculate different way.
    Hope this help,

Thats nice what you did! We shall see the way to validate your tutorial and indeed add it to our tutorials .What do you think @mengdahl ?

Yes, great idea. We should create FAQs for the toolboxes and SNAP in general and link to external tutorials from there too.

Hi @Fikretjfm

Thanks for your support

The last step processing give me this error!!!

Could you show me the folder PATCH1 for exmple and Did you change .m file provided by Feiliu? And did you change processor doris to gamma?


it looks like the bin directory is not in the matlab search path.

Add folders to the search path.

run the following:



The PATCH folders are not in an ideal directory. Running StaMPS will export files in its bin folder along with script files. It is recommended you rerun mt_prep_gamma and export in the master InSAR directory (where diff0, geo, dem, rslc are located).

Good luck


I also have the same results after @thho has helped me with the successful installation.

I have renamed my ps_initial_…(changed) file to the ps_initial file and removed the older “initial” file.
I have also done what some may have suggested as change the gamma in the getparm/setparm.

before I have made these changes, my error looks like this: PSI: Error on first step on Matlab

@ABraun I am using Linux Ubuntu but I also received the same error as you. Any new findings?

I am looking to view PS in highly urban area but there are a few nature reserves around, hence there should be obvious non PS areas in my project if it does succeed.

If anyone is stuck at the Linux phase of the installation, you can view the thread here Linux Installation using StaMPS and S-1 data

Hello @Fikretjfm,

It is a late response but maybe it is still helpful for you, and maybe it will be helpful for others. I just got the same error index out of bounds because size(ij)=[0,0]. I recognized that one scene was not processed properly. I noticed it during the mt_prep_gamma_snap step before entering matlab:

The scene of 2017 Nov 08 seems to have zero mean (see the WARNING message in terminal), which is highly suspicious. I had a look at the stack in SNAP and all bands of this date were empty. I think the error occurred during ApplyOrbitFileOP but I was not able to redo it. After processing a new split, apply orbit file, stack, deburst, subset and export, the warning during mt_prep_gamma_snap disappeared and I was able to run stamps(1,1) without a single problem!