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

Have you solved this problem yet, would you please tell me what is the problem?

I have been testing minimum surfaces but they have all given me the same error, would you know roughly tell me what could be the minimum dimensions in which good results are obtained in the detection of PS? @ABraun

I don’t really know if there is a lower size limit. What areas did you test?

I did not obtain a satisfactory result in any case, perhaps due to having started from too small surfaces; the last one used was 500m x 500m; so stop dwelling on it. and I continued using large surfaces; If I will try the minimum surface test in the future again, I will let you know

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Hi modeste

Please how Can I get this figure ??


Regarding the “Dimensions of arrays being concatenated are not consistent” error, please use the search function of the forum, this problem has been discussed and answered multiple times:

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Dear Fillppo
I have the same problem as you,when I run the stamps(3,3) , I have 9 PATCH, but some PATCH show this:
Warning: Not enough random phase pixels to set gamma threshold - using default threshold of 0.3

In ps select at 184
In stamps at 357
In this case, there are still PS points.

But in some PATCH ,show this:
PS_SELECT: Initial gamma threshold: 1.000 at D_A=0.05 to 1.000 at D_A=0.40
PS_SELECT: 0 PS selected initially
PS_SELECT: Reestimation gamma threshold: 1.000 at D_A=0.05 to 1.000 at D_A=0.40
PS_SELECT: 0 PS selected after re-estimation of coherence

I have no idea to save the problem, can you give me some advice?
thank you, I am waiting for your reply!

there seem to be patches which have a very little amount of PS, which can have two reasons

  • there water bodies in larger parts of your data
  • the patches cover small areas., then you could reduce the number of patches in the mt_prep command

Thank you very much, Mr. ABraun.
Thank you for your guidance. I will test it. I hope we can discuss it further.
I just started using stamps recently. Can you give me some advice on parameter facilities.
For example, a set of universal parameters for high coherence large-scale deformation monitoring.
Thank you very much!

Hi @SJ-RS,

setting StaMPS parameters is quite unique to your study site. However, for a start you can have a look into my thesis. What I did might resemble your application, I reported the most important parameters on pages 42 and 54

  • Parameters on page 42 are for a larger area in an inland, mountainous region
  • Parameters on page 54 are for a smaller area in a city in a rather flat to slightly hilly, coastal area

Maybe that will help you as a starting point!


Thank you very much, Mr. thho.
I will carefully study the documents you provided.

Dear Mdelgado,
Is it Enhanced Spectral Diversity step present in this script or not? Because I didn’t find it in python code.

Thank you.

yes, it is contained in the coregistration script which calls the XML including BackGeocoding and ESD

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Dear experts
I encountered some problems running step (1,1) of stamps-sbas:

Index exceeds matrix dimensions.

Error in sb_load_initial_gamma (line 146)
bl=mean(sort_x(1;n_pc,:)); %bottom left corner

Error in stamps (line 221)

I have no problem in PS; I don’t know what’s going on. Can you give me some suggestions?
I’m looking forward to your reply.


This was a figure I have done during my PhD and I don’t have it anymore.

And so far, I do not have found a satisfactory answer to explain this dispersion on my Time Series.
Mean LOS velocities, essentially vertical in my case, were coherent with the time evolution of the monitored phenomenon (residual mining subsidence).
Atmospheric corrections with weather data and analytical correction (from TRAIN software) has been tested, but the dispersion persists …
A colleague of mine had the same problem of dispersion in the TS while studying Egyptian area.


I am trying to export my debrust and dinsar debrust image for PSI processing in STAMPS but I am getting this error. Kindly help me how I can resolve it?

please make sure to select “topographic phase removal” in the interferogram operator and select “output elevation” and “output latitude and longitude”


hi all

pardon me, for i have a beginner question and could not find the answer
so i know that sentinel 1 SLC has pixel spatial resolution which is 2,7-3,5 meter in range direction vs 15,5 meter in azimuth direction,
so after i have done the ps insar method, i obtain deformation rate value in geometrically corrected image, so my question is what is the pixel spatial resolution for the result ? since i couldnot find the parameter in StaMPS

thank you for your answer and time

oh one more thing,
is there any sattelites recommendation to do PS interferometry SAR for years 2010 or before sentinel 1 exist ?


The spatial resolution of PS approaches is different from the pixel resolution because the time-series approach allows to locate the scatterers at sub-pixel precision.
Some general remarks are given here: Persistent Scatterer localization and prediction technique
More details are presented in this review paper: Recent advances in SAR interferometry time series analysis for measuring crustal deformation

I’m quite sure that there is a way to find out the spacing of the PS in StaMPS/Matlab, maybe someone in here knows it.

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thank you for your valuable answer Sir ABraun,

i will read the papers you recommend first, and if i am still stuck maybe i will ask a question again to make it clearer, (hope you guys dont mind)