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


Had you verified if your processing had giving you any warning or error messages ??

Had you tried to do it following any manual? Normally this should help.


followed snap-stamps flow by Katerine


no its the first error. other earlier generated products were verified visually.


Maybe you got any “No space disk on device” and this product is empty?

I am not aware of Katherine workflow, so better you ask her directly.
I can help you to verify the basics, besides I am not SNAP developer …


Ok thanks a lot…


If you would not manage to solve the problem, you may like to try this other workflow: Snap2stamps package: a free tool to automate the SNAP-StaMPS Workflow which I have developed and I would probably be able to help in case that something would not work.

But still, my advice is that if you have started with Katherine’s workflow, try to figure out the issue you got, otherwise you may start again from scratch.


surely i will update you my progress and try this software too.


Hello mam,
Please help me in StaMPS processing…
I have followed your SNAP-Stamps workflow.
I have created subset_master_stack_deb its its fine. results are satisfactory in Image view.
then i did interferogram formation and got subset_master_stack_deb_ifg, but the coherence,phase bands are not opening giving error;
failed to open image view


Dear mdelgado,
I have downloaded your package. But the problem is ; i have been working on a virtual machine and don’t know how to install it.
Could it be installed through terminal?


The only requirements are to have SNAP v6.0 (or higher) and to install the pathlib package (if not present already). The rest of python scripts are ready to go.
Good luck and enjoy!


Hi Bayzidul,
I have done split_orb for 32 images; created stack in Backgeocoding; added Lon,Lat bands;deburst;subset and created product subset_master_stack_deb successfully opening in image view and deburst verified.
Then i did interferogram generation taking subset_master_stack_deb as input and got
subset_master_stack_deb _ifg,
here neither coherence nor phase bands are opening in image view giving error:
please help to fix it.


Hi Katherine,
Same products i got (as u have in last screen shot) but phase,coherence bands can not be opened. giving java.lang.NullpointerException error

Why so?


Dear thho, I couldn’t download your summary.
Please mail;


null pointer error fixed. May be i have not added elevation and lat lon bands properly or subset was not proper.
Products are being exported to Stamps now.


dear Abraun,
Congratulations, thanks a lot for your support.
java.lang.NullpointerException error removed and a small stack exported to Stamps. Got four rslc, geo, diff0, dem.
Now i will be exporting next two stacks to Stamps. Please guide how to combine/copy other similar folders in these folders.


Can you say what caused the Java error?

if all were coregistered against the same master, you can probably just copy the files from rscl, geo and diff together in one. But I haven’t tried it that way myself.


it resolved in hit and trial. can’t surely say. Exporting next products will convey if found that error again.


i debursted after interferogram too.


I feel one should complete processing coregistration stack and its interferogram first. Then deburst each.
Faced same problem. Now following the above said flow.


Well Virk, you could just follow the indicated workflows by Katherine, mine or other’s peoples comments. Probably you would had avoided that problem from the beginning by reading a bit first about TOPSAR processing in SNAP.

Still, I am happy you have managed to solve your problem.
So, well done!