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

Hi @ABraun,

But I also processed the same area before with SNAP v6.0 and StaMPS v3.3b.
At that time, I used 66 images of sentinel-1a during 2014/10/22-2017/10/30, and the result with a basemap is as followed (to emphasize the distribution of PS, I use the same color of them):

Now, I used 24 images of sentinel 1b and 23 images of sentinel 1a during 2019/01/01 - 2019/09/28, and the result with a basemap is as followed:

In the result I got before, the distribution of PS points seems randon. Also, I never got linear alignment of the PS in other cases before.

Because this is the first time I processed sentinel 1a and 1b data together with SNAP v7.0.2 and StaMPS v4.1 in Windows Subsystem for Linux (ubuntu 18). So, I’m not sure the result I have now is correct or not…

Thank you very much!

to my opinion, this is because you are investigating a shorter time (less temporal decorrelation), which leads to a higher density of usable PS

I just got the result (show as red point) using same imsges during 2019/01/01 - 2019/09/28 and parameters but processed with SNAP v6.0 and StaMPS v3.3b. They looks very different with the same data processed with SNAP v7.0 and Stmaps v4.1, the PS points show as black circle as followed:

I don’t know which is correct …

I found what happen!

I didn’t notice that one parameter default set is different between StaMPS v3.3b and v4.1.
In v3.3b, the “weed_neighbours” is “y”, but in v4.1 it default set is “n”. So, I got more PS points!

But, which one is better of the parameter “weed_neighbours”?

Thank you.

weeding should be strong enough to remove faulty or noisy PS, but still leave enough PS for the later steps. If the pattern you see makes sense, leave them in.

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OK! Thank you for your help and explanation.

where we can get this ps_load_initial_gamma.m file? kindly if you can explain it…

Replacing scripts is no longer needed since StaMPS 4.1, you directly use mt_prep_snap

Dear Katerine, Daer other users,
I have follow the steps that Katerine gave. Everything is going well except the StaMPS export.
In the StaMPS Export, I have put the 2 right files but I faced a wrong message (“Orthorectified lat/long bands required. Please add the bands to the interferogram product”). I do not know why I received this particular message. Someone have an idea how I can solve it. Thanks for your support and your help.

did you check this option during the interferogram generation?


It is deactivated by standard.

Thanks for your support. It works now !

Why this error message?
I worked the data with PSI.
Any suggestions please.

Thank you,

good morning, could you solve that problem? please

Hi all, I have the following error during the run of PATCH 4… what can I make???

I am using StaMPS v3.3b1!!!

Thanks for advance

have you installed triangle on your machine?

For variable ‘a’ you must run atmospheric correction from TRAIN you can find in
And to plot ‘a’ you must add additional string e.g. ps_plot(‘u-a’,‘a_linear’).

Ready! I just installed it!!!
Run again?

yes, run step 4 entirely again.

ok running…

thanks Andreas

you also need to have snaphu compiled for step 4 (sorry, I don’t know which step you were at with the triangle error.)