Workflow between SNAP and StaMPS


#8

Hello Luis,

Thank you very much for your effort. Could you please send me a pre-release version of the toolbox? I would like to test that function, too.

Thank you!


#9

+1

… (20 character limit) :wink:


#10

The StaMPS export in SNAP 5.0 works fine to me.
It creates three folders:

  1. the interferograms
  2. the DEM
  3. the coregistered stack

If I understood it right, this skips the chapters 3-5 in the StaMPS manual and now we can directly proceed with Matlab.
http://homepages.see.leeds.ac.uk/~earahoo/stamps/StaMPS_Manual_v3.1.pdf

I installed matlab and wanted to apply the scripts provided within STAMPS to the generated output:

There is a great tutorial by Dr. Mahdi Motagh from the SAR summer school 2016:
http://sar-edu.uni-jena.de/wp/downloads-2/ (download ‘Time Series’) and open "SAR-EDU_stamps_Motagh.pdf)

But I must do something wrong. Is anyone experienced with the selection and analysis of persistent scatterers and how to apply it to the data exported by SNAP?


#11

Currently SNAP only produces the inputs required by StaMPS. You need a stack with at least 4 interferograms. Running stamps automatically doesn’t seem to be enough to get a good result for any scene. People familiar with StaMPS have said it needs adjustments at the various steps. I’m not knowledgeable on PSI to recommend how to use StaMPS. Next we need to figure out how to make use of the data produced by StaMPS back in SNAP.


#12

thanks for the answer.
I have a stack with 8 SLCs (7 interferograms). I could imagine that there are some variables with need to be adjusted within the StaMPS workflow (I had a look at the MATLAB scripts), but I already struggle adressing the exported data.
Maybe someone has already worked with StaMPS and can test how to use the SNAP exports.


#13

8 images is a very small stack for PS identification, usually 20+ scenes are used/recommended. Perhaps the people on StaMPS-forum could help:

https://groups.google.com/forum/#!forum/mainsar


How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP
#14

thanks, mengdahl, I’m fully aware of that. The thing is that I wanted to test the technical application before I create a monster stack :slight_smile:

But the forum is a great hint, I didn’t know it yet!


#16

Hello ABraun,
I tried to export to StaMPS the stack of four S-1 images with corresponding interferograms. But got an error. Could you, please, share your experience with export. What do I do wrong? Below are my graphs. I have used for some time StaMPS so probably when I overcome export from Snap to StaMPS it may go smoother.



#17

For S1, you need to apply orbit and TOPS split.
Then you can add all products to the backgeocoding.
Create a stack of interferograms on the resulting stack.
Deburst both the backgeocoded stack and the interferogram stack.
Add an elevation band to the interferogram stack.

Add debursted stack and debursted interferogram stack to the stamps export.

I could update the stamps export to allow multiple individual interferograms. This would allow you to choose slave-slave pairs.


How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP
How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP
How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP
#18

Hi Luis,
It seems I have done everything you said. Could you, please, have a look at my graphs. Thank you very much for your time.
Katherine


#19

I used Envisat data so no debursting ect was needed, sorry.
I created:

  1. One stack containing 8 SLCs
  2. One interferogram product as produced by the interferogram module containing one interferogram per slave image
  3. An elevation band added to the interferogram stack by right-click > add elevation raster.

#20

Dear ABraun,
Thank you very much for your answer. My main target is to work with S-1 images. Mostlikely it is no need to use SNAP export to StaMPS with Envisat images as Stamps is adjusted for Doris. So Doris in this case is much better.
Thank you again for your wish to help.
Katherine


#21

Dear Luis (or probably somebody from the community who already tried this function),
Thank you for your explanations - I managed to move a little bit forward. I tried to export to Stamps all interferograms (Orb_Stack_Ifg_Deb and resampled images (Orb_Stack_Deb) from my stack at once - that was my mistake. When I tried to export only two Products at the same time (resampled image 0604_Orb_Stack_Deb and the ifg of this image with the master 1107_0604_Orb_Stack_Ifg_Deb) I got the new error


But I do not see such a band in this Product. Could you, please, give me an advice how to overcome this.
Thank you very much for all your help
Katherine


#22

could you please also show us the ProductSet Reader Tab?


#23

Here it is. Thank you very much for your time!
Katherine


#24

looks the same as in my case.

Can you please also show a screenshot of all the bands in the two products?


#25

Here they are! Thank you again for your time!
Katherine


#26

according to the Help menu your stack must have at least 5 SLCs (1 master and 4 slave bands)
The rest looks like my data.


#27

Dear ABraun,
Thank you for your time!
Yes,4 ifgs and 5 SLCs - it is the requirement of Stamps. This is necessary for mt_prep_gamma. And at first I tried 5 SLCs with corresponding 4 ifgs.But in this case “Stamps export” from SNAP did not work at all. I had the error which I put in my earlier post (I attached it once again). Luis Iveci wrote:
“I could update the stamps export to allow multiple individual interferograms. This would allow you to choose slave-slave pairs”.
I suspected that probably at present pairs (1 ifg and 1resampled image) can be exported to Stamps only individualy… But it is only my presumption…
If somebody from the community have already used the SNAP “export to Stamps” with S-1 images successfully , please, share your experience!
Katherine


#28

Dear Katherine,
At first, you should co-register your images using back-geocoding functionality, that supports Sentinel stack co-registration now. (Radar -> Coregistration -> S1 TOPS Coregistration -> S-1 Back Geocoding)
Secondly, SNAP didn’t allow me to export with “topo-phase removal” step done. So I didn’t do it by now.
Mine processing chain looks like this:
Apply Orbit File to each image -> S1 tops split -> back geocoding of stack -> interferogram formation -> Add elevation band to last product in the chain
Talking about deburst and subset operations I am not fully sure yet. It seems that you can deburst, subset co-registered stack and interferogram stack individually or deburst, subset at first and then generate interferograms out of subset.

Don’t exprort too small area. It should be definately larger than 2km x 2km. Otherwise StaMPS will find zero permanent scatterers.

During step nr. 6 you may need to decrease values of parameters “unwrap_grid_size” or “unwrap_gold_n_win”. The less image you exort, the more parameters will need to be decreased.

I still have some problems incide StaMPS though. The image is stretched, points are geocoded near zero co-ordinates and deformation values are unnaturelly huge.

Jaroslav