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

virk_rana · November 11, 2018, 10:58am

yes with same master. Actually taking all 32 images were creating problems.
Now it seems fine.

ABraun · November 11, 2018, 10:59am

alright, so you can go on in Linux now.

virk_rana · November 11, 2018, 11:05am

Dear thho,
I have completed Katherine’s workflow upto point 8. Please help me to understand step 9 and further StaMPS processing…
Regards

thho · November 11, 2018, 11:25am

Dear @virk_rana,

currently there are many workflows about this topic out there, can you link to the one you are using? Maybe I can help you then. Concerning StaMPS processing: This is highly case study dependent, I recommend to read the literature linked below to understand StaMPS and its parameters. Technically, running StamPS in Matlab is straight forward, follow the manual linked below.

virk_rana · November 11, 2018, 11:37am

Yes i have read some of these. I have successfully processed sentinel 1 data for subsidence detection already and chosen these stacks accordingly.
Actually i am on a VM installed with SNAP,QGIS,BRAT GUI,R-studio etc. StaMPS and Matlab are not being traced by me there.
Asked VM providers to help me too.

Remote-Rradar · November 15, 2018, 9:08pm

Hello bayzidul

In step 13: (How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP)
«mt_prep_gamma» is executed by what software?
Where?
How?
Below fig show main folder (INSAR_master_data)

and below figs show StaMPS-4.1-beta folder

===
dem:

===
diff0

===
geo

===
rslc

thanks

ABraun · November 16, 2018, 5:31am

You open your linux shell, source the config file as described in the manual and then navigate to a new working directory (at best empty) and run the command pointing to the folder where you exported the data from SNAP. The files will be created there.
Please have a look here: How Can ı Run mt_prep_gamma script in Cygwin for PS/Stamps application? Help please!

Remote-Rradar · November 16, 2018, 8:40am

Hi ABraun

Can not I run it in Matlab software?
Copying, and transferring the folder(INSAR_master_data ; about 13G) takes a lot of time?
Thanks

ABraun · November 16, 2018, 8:56am

These are the required steps:

prepare all stacks and interferograms in SNAP and export them
run mt_prep_gamma in a Linux shell to make them readable to Matlab
use the StaMPS matlab scripts to process the persistent scatterers

Remote-Rradar · November 16, 2018, 9:18am

That’s right, I did it. but below error(command not found)

In the top posts, pointed to a lot of errors, When we execute the commands.
What is the best version of StamPS? have had the more less error

thanks

SSSumi · November 18, 2018, 6:28am

Hi, dear all.
I am very confused how to compute the deformation maps from the unwrapped and corrected phase using StaMPS, a suggestion is to change the StaMPS Matlab source code called ‘ps_plot’, just add the codes like these, ‘ph_all =-ph_all*55.5/4/3.141592653’, is it correct? And is there anyone having drawn the deformation map of each slave image referenced to master image?
Thank you a lot!

ABraun · November 18, 2018, 8:52am

actually, the StaMPS scripts do all that for you without the need for any adjustment.

have a look at chapter 4 of this tutorial: http://seom.esa.int/landtraining2015/files/Day_4/D4P2a_LTC2015_Hooper.pdf
It shows many ways of plotting single images and pair-wise deformation maps.

Also a very good source: https://www.unavco.org/education/professional-development/short-courses/course-materials/insar/2016-insar-isce-giant-course-materials/Hooper_Lecture_PS.pdf

SSSumi · November 18, 2018, 10:05am

I’m very happy that you have shared such wonderful sources, it’s helpful, especially the last one which I haven’t found. But commands about plot at chapter 4 are mainly to draw phase maps instead of deformation, and ps_plot(‘v’) or ps_plot (‘v-d’) don’t show the deformation between the master image and slave images. I don’t know whether is correct to add sources like ‘ph_all =-ph_all*55.5/4/3.141592653’, means change the phase to surface deformation. Thank you a lot!

ABraun · November 18, 2018, 10:11am

Now I understand. I haven’t tested it but the actual equation to convert the unwrapped phase to elevation also involves the incidence angle.

(unwrapped_phase * wavelength_in_mm) / (-4 * PI * cos(rad(incident_angle)))

But I am not sure how these variables are already present in Matlab. Where did you find this equation?

I currently have no access to StaMPS but I will have a look if there is a plot_command to show all pairwise displacements in one map.

SSSumi · November 18, 2018, 10:43am

Thank you again, ABraun! The equation ‘ph_all =-ph_all*55.5/4/3.141592653’ is to compute the LOS deformation, I think it is the same with yours, but I use the specific values to replace the variables, such as wavelength_in_mm replaced by 55.5, although I don’t know it is appropriate. And ‘ph_all’ in StaMPS Matlab source codes is stand for a array stored the phase of all interferograms.

ABraun · November 18, 2018, 10:59am

sure, I was just using variables, but I am still missing the last part on the incidence angle.

ABraun · November 20, 2018, 4:55pm

I didn’t find one to be honest. All plots created with ‘v’ only show the average displacement so you might in fact need to derive it from the unwrapped phase (‘u-dmos’ is the unwrapped phase minus dem error, AOE, orbital ramps and topo-correlated atmosphere)

zhuhaxixiong · November 21, 2018, 6:34am

I have finieshed all the process in this part and get a displacement with 10 infer image,now i want to add the data to 30 image, when i do he step(ifg),the process is really long and when i get to about 70% of inter, an error occurs.i want to know the reason,first i think it is becasue the too manny images,may i need to creat two more stack to process,can you give some advice

ABraun · November 21, 2018, 6:51am

What’s the error message?

SSSumi · November 21, 2018, 6:58am

Hi, ABraun, thanks for your suggestion.I will try it.