error:[Nodeld: Back-Geocoding] same sub-swath is expected snap,

Addtional, i have changed computation_subset.xml as a below bcz of its single burst. Otherways, i was getting error explained in here.

In case you prepared the master manually (as suggested), did you reduce the master to one polarization (VV)?

Not yet. Master containing VV, VH of IW2, burst 4. And all of slaves containing only VV

Please select VV during Split of the master

Yeah. It was. Thank you expert.

Hi!

I just want to ask how did you manage to solve this issue?

I have the same issue now also. I have double checked each image (split_orbit) and they have the same IW, polarization and bursts.
image

Thank you in advance.

Can you please post a screenshot of the WorldView window showing that all products cover the same footprint?

Here is the screenshot. There is no shift in the frame and the subswath from each acquisition has the same number of bursts. Hence, I did Batch Processing for both splitting and orbit-file correction. But because of the error, I ended up exploring snap2stamps.
image

It works fine in Windows.

By the way, thank you for your immediate response regarding my other concern about snap2stamps. It’s working well already.

Will do stamps_export soon.

Thank you!

alright - so your problem here is solved for now?

If I execute the stacking in Windows, no issues. But the problem is persistent in Linux.

Anyway, the snap2stamps software is very helpful.

I was able to complete a PSI analysis using StaMPS/MTI for my pilot test using very few SAR data. Below is the displacement velocity map for this pilot test.

I am studying now STEP 9 which is tropospheric correction using TRAIN, and later will do some post-analysis.

And finally, will increase my SAR data (more than 20).

Big thanks to this online community, especially to you and to @mdelgado.

2 Likes

Hi I have a question, why I can’t do the geocoding with different track and pass?

BackGeocoding allows to coregister SLC products at sub-pixel accuracy, e.g. for interfefrometric analyses. These work only on images acquired from the same track (explained here).

If you want to use information of products of different tracks, you have to geocode them first (Range Doppler Terrain Correction). If you don’t need the phase information, GRD products are sufficient.

thank you for response! I’m starting to study the treatment of SAR images. I am interested in the InSAR and Din-SAR techniques. Your link help me a lot!
But if the two set don’t cover the same area and I crop both to make it, eg using “Spatial Subset” I have the same result?

You can use SLC products which are shifted along-track and select the corresponding bursts in the TOPS Split operator.
But you cannot combine products of different tracks for InSAR or DInSAR.

Maybe these tutorials are helpful to you:

Screenshot from 2023-02-20 17-50-05

can someone solve this error?

Have you tried ensuring that identical polarization is selected for both inputs? That is what the error is saying.

yes have ensure it. but still the same, i using windows platform there is no error, but in linux there is the error

hello sir, I want to ask something, I got the result for my deformation, but the PS POINT did not lies on the coordinate for my monitored stations using GNSS as validation, is there a possible chance for me to improve my processing inside stamps?

Hello. Quick clarification, does that mean it is not possible to do across-track interferometry in snap using two images? My AOI is located in IW2 of my first tile and in IW1 of my second tile. Are you saying I could use the range doppler terrain correction first and then do the back-geocoding?

You cannot do that. These images have different viewing geometries ans their phase information cannot be exploited.