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

Try to apply this

Hi @Alex_P,

I have run mt_prep_gamma inside my “export” folder, so I don’t know why I still get this strange error…

Thank you!!

Dear all,

I have solved this problem!
Thanks @FeiLiu give me some important hints!
It was due to the version of StaMPS_v3.2.1, when I changed to StaMPS_v3.3b1, everything is fine!
Now I could move to the next step!

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Dear all,

i have problem with ps_load_initial_gamma
Please help me, give some hints. Thank you

Dear, bayzidul.
If you do not find it difficult to describe all the steps that you have taken to obtain such a result.
All the best.



The workflow described in this post (and the ones referring to it later on) is outdated and no longer recommended, because new versions of SNAP and StaMPS have been released. Please have a look at this updated list of instructions: StaMPS - Detailled instructions

Hi @Alex_P, here the steps I had followed,

  1. Apply TOPS split and then Apply orbit file.
  2. Add scenes (Master+Slave1 and Master+Slave2 and so on ) to do the Backgeocoding separately for each Master-Slave pair.
  3. Create Stack of Backgeocoded images (master_Stack1, master_stack2 and so on).
    NB: I have used SRTM 1sec HGT (Auto download) DEM and Cubic-Convolution method
  4. Create a stack of Interferograms (master_stack_ifg1, master_stack_ifg2 and so on for all pairs), Deburst and Topographic phase removal (master_Stack_ifg_Deb_dinsar1, master_Stack_ifg_Deb_dinsar2 and so on).
    NB: If you see EAP error then you have to apply EAP for the scene before Back-gocoding (you have to apply EAP either for master or slave that you have to check, images before March 2015 need EAP correction)
  5. Make sure to deburst both the Backgeocoded stack (master_Stack_Deb1, master_Stack_Deb2 and so on ), and the Interferogram stack already debursted**(master_Stack _ifg_Deb_dinsar1, master_Stack _ifg_Deb_dinsar2 and so on).**
  6. Add an elevation band to the Interferogram stack for all (by right-click > add elevation raster).
    NB: I have used SRTM 1sec HGT (Auto download) DEM and Cubic-Convolution method
  7. Add the Debursted Backgeocoded stack first and then Debursted Interferogram stack to the stamps export.
    NB: If you do subset then do it with same Geo-coordinates for master_Stack_Deb1_subset and master_Stack_ifg_Deb_dinsar_subset (you can also do subset before dinsar to save some time)

    Export to StaMPS the two files:
  8. master_Stack_Deb AND master_Stack _ifg_Deb_dinsa
  9. StaMPS Export will generate four directories (/diff0, /geo, /dem, /rslc)
    NOTE: For all the Stacks export each Stack and then copy results in the directories (/diff0 and /rslc), no need to copy for (/geo, /dem) is same for all pairs.
  10. To have PS geocoded add (Lon & Lat) bands to the result of 5 (master_Stack_Deb) [do it only for one pair]
    NOTE: (Right click -band maths, then edit expressions, select lon from constants (lat in the second time). It will add Lat and Lon band in your master_Stack_Deb data and then Export it to GAMMA format. Now rename the lon and lat file as 20150118.lon and (20150118 is the date of your master data), copy this two file and place into /geo directory.
  11. Place the new scripts mt_prep_gamma_snap to the /bin directory of StaMPS (you can rename it as mt_prep_gamma and replace the existing file).
  12. Place ps_load_initial_gamma_snap.m to the StaMPS /matlab directory (rename ps_load_initial_gamma.m and replace the existing file).
  13. Run mt_prep_gamma from the data directory (cd to the folder where you have your all exported data).
    HINTS: mt_prep_gamma_snap [masterdate in format yyyymmdd] [data directory] [amp_threshold] [rg_patches] [az_patches] [az_overlap] [rg_overlap]
    {for instance: mt_prep_gamma 20150118 /Insardata/Stamps_export 0.4 1 1 50 200}
    NOTE: You can use mt_prep_gamma_snap (changed) and ps_load_initial_gamma_snap (changed).m provided by FeiLiu. If the script ps_load_initial_gamma_snap.m and ps_load_initial_gamma_snap.m provided by Katherine are workable then everything is also OK.
  14. When the process is finished, type matlab in the console and in the matlab type stamps.

I hope this will help



This steps are like of falahfakhri tutorial’s, thanks so much! @falahfakhri and @bayzidul

I have a question, after of I generated all stacks (TOPS Split, Apply Orbit File and Backgeocoding) I have that make deburts for each pairs of this set???
and after, I have to make all ifg (ifg, deburst, topographic phase removal)???

I have 22 images and 21 pairs with same master image! After, I have to prepare the final stack with STACK AVERAGING??? is same for ifg stack final???

Are two set data? a stack averaging AND stack ifg??? this step I don’t understand

Thanks for advance

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I don’t think stack averaging is needed in general, especially not for PSI.
But having interferograms of all image pairs (AB, AC, AD,…) in one product is the aim.

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Thanks ABraun

After of to check the steps @falahfakhri tutorial’s and @bayzidul again, I go to make the following:

1.- From 22 images and 21 pairs where the combinations are (AB, AC, AD, AF,…),

  • TOPS Split
  • Apply Orbit File
  • Backgeocoding
  • Ifg
  • Deburts
  • Topo Phase Removal
  • to STACK add Elevation band
  • Export StaMPS

Am right?

If you are interested in time series, stack averaging doesn’t make sense to me. By doing this, you would reduce the temporal information of all images to one product which cannot be used in StaMPS anymore.
If you want to build a DEM from various image pairs that would be an option but then PSI is not the best technique to achieve this.

Hi @ABraun thanks for your reply

I want to generate a displacement map on an area in specific, we want to know crustal deformation of this, we want not DEM and yes, I want to work with time series, so, I don’t make stack averaging, only I create a stack???

Thanks for advance

yes, absolutely.

I can really recommend Andy Hooper’s paper:

I am beginner, how can I calculate PS of S1 using ESA NEXT or ENVI?

This is a very good start: How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP 5

Hi Dear Andreas, what is wrong ??? The stack is not with pairs???

@gabrielaquintana77 I haven’t tried it but this seems more reasonable.

Hi @gabrielaquintana77, I think @ABraun is right and I had also avoided Stack Averaging.

I had problems with the reapeted use of graphs in Snap for create stack for time series. I don’t know if someone else have dat the same problem.
Please, take a look.

Hi @ABraun, I have followed the suggestion of @bayzidul. But when I export it , it gives an error

I even tried the sequence master_Stack_ifg_dinsar and master_Stack ifg¬dinsar_Deb. But the result are the same.

Can you help me?

From you screenshots I saw that you created a subset. At which step was this done and why didn’t you use the TOPS Split function to reduce the image size?