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

gabrielaquintana77 · February 14, 2018, 2:55pm

I did the replace of the scripts mt_prep_gamma_snap to the /bin directory of StaMPS and ps_load_initial_gamma_snap.m to the StaMPS /matlab directory…

I did the change from insar processor doris to gamma

And later I typed stamps

Fikretjfm · February 14, 2018, 3:29pm

Hi @gabrielaquintana77,

It is good to see you could handle some of error. I wonder after you changed the scripts ps_load_initial_gamma and mt_prep_gamma_snap, did you do mt_prep_gamma_snap step again and then just typed stamps??? I see stamps(4,5) so you need to do same steps with new scripts. Also is pscands.1.ij file empty or not?

After you do same steps again you will see psver.mat file, the program could not find this file right now.

Fikret

gabrielaquintana77 · February 14, 2018, 3:44pm

Hi @kouhartsiouk

I did, in this moment, your suggested for me and this is the result

gabrielaquintana77 · February 14, 2018, 3:53pm

Hi

Yes, this file is empty…

Fikretjfm · February 14, 2018, 4:04pm

Hi,
You need to do mt_prep_gamma_snap step again with new script. Then you will see the .ij files will not be empty.

Fikret

thho · February 14, 2018, 7:03pm

Hi @gabrielaquintana77 your screenshots and errors are very similar to those @hchong005 posted here. Please have a look in this thread, and follow the described steps, they may solve your problems.

gabrielaquintana77 · February 14, 2018, 7:18pm

Thanks very much @Fikretjfm @thho @kouhartsiouk for your support, in this moment, I am checking all steps and making the modification necessary

sanchez01 · February 14, 2018, 11:52pm

how could to solve this problem… in matlab… can anybody help me

Fonna · February 15, 2018, 9:51am

Hello everybody.
I’m trying to do InSAR from two Sentinel-1A images.
Based on @bayzidul steps, i’m wondering about two steps inside:[quote=“bayzidul, post:252, topic:4981”]

Apply TOPS split and then Apply orbit file.
Add scenes (Master+Slave1 and Master+Slave2 and so on ) to do the Backgeocoding separately for each Master-Slave pair.
Create Stack of Backgeocoded images (master_Stack1, master_stack2 and so on).
[/quote]

I’ve done with the first step.
Now I’m trying to do the back-geocoding for only two images. When I was performing Radar > Corregistration > S1 TOPS Corregistration > S1 Back-Geocoding and click Run, the warning “Not able to write product” shown, so the process failed.

But when I did the back-geocoding for each image, it worked well.
The problem arised when I tried to stack those both images through Radar > Corregistration > Stack Tools > Create Stack. The error message “[NodeId: 2-CreateStack] S1 TOPS SLC products should use TOPS Coregistration” appeared, so I have no result of S1 TOPS Coregistration.

What I want to ask are:

Why can’t I stack both of the geocoded images?
What should I do to have the perfect coregistration result?

Fyi: I work with 4 GB of RAM and I’ve already checked “Use FileCache in readers to conserve memory” in the Tools > Options > S1TBX.

bayzidul · February 15, 2018, 10:52am

Hello @Fonna

Please read the previous comments and then you will find some limitations and recommendations of PS processing with Sentinel-1 data using the combination of SNAP and StaMPS.

If you are using the current version of SNAP-6 then there are some changes in the steps that we had written here in previous discussions.

From my experience, you need at least 16GB memory and it is way more better to work in Linux. From you snapshots, my comment is to change the PC configuration first and even you have to choose the correct Geocoding method.

Thanks

Fonna · February 15, 2018, 11:03am

Thank you for your fast reply!
Maybe because I’m using SNAP-6, the steps I following had been changed
I will try to use another computer with greater RAM size to do the back-geocoding correctly.

gabrielaquintana77 · February 15, 2018, 2:16pm

Please, explain me more!

Fikretjfm · February 15, 2018, 2:32pm

Hi @gabrielaquintana77,
You changed two scripts with new ones. Good. Now, you need to do mt_prep step again.
Fikret

gabrielaquintana77 · February 15, 2018, 2:42pm

thanks for your reply @Fikretjfm

let me see if I understand, you talks about of make the processing with the command

mt_prep_gamma 20160208 /sdd/RESULTADOS1 0.4 2 2 50 200 again?!

if this is case, I did, but the pscands continued empty!!!

Fikretjfm · February 15, 2018, 3:55pm

Yes but you changed the name of script to mt_prep_gamma or did you just copied and pasted new script into matlab folder. Because your command should be start mt_prep_gamma_snap not just mt_prep_gamma if you did not replaced with new one.

gabrielaquintana77 · February 15, 2018, 5:18pm

ah wow!!! let me make again the copy and pasted of the scripts and the run again!!!

gabrielaquintana77 · February 16, 2018, 1:05pm

Hi @Fikretjfm

Yesterday, I did ran the script again, this time

./mt_prep_gamma_snap 20160208 /sdd/RESULTADOS1 0.4 2 2 50 200

and this time, I can see that executed pscands.1.ij0

but, I think that the processed not overwrite the PATCH files!!! because this give me error when I want to plot

I readed the suggestion from @thho , so, my question is, I have to modify this script ps_plot.m or getpsver?
http://forum.step.esa.int/t/linux-installation-using-stamps-and-s-1-data/8752/13?u=gabrielaquintana77

thanks very much for advance

Fikretjfm · February 16, 2018, 3:26pm

Hi,
You need to delete Break commands in some .m files. I will send you my runnable matlab folder. But ı am not at home at this weekend. I will send next Monday.
Fikret

gabrielaquintana77 · February 16, 2018, 4:10pm

Thanks @Fikretjfm I will wait for you!!!

Fikretjfm · February 18, 2018, 10:26am

Hi,
We returned back today and here is my matlab folder. Just copy and paste all files.
Fikretmatlab_folder.rar (148.6 KB)