InSAR image coregistration + Stacks

I’d have three questions regarding InSAR image coregistration:

  1. If I go to Radar > Coregistration > InSAR Optimized Coregistration, I can coregister a number of (say TSX) images with a single master. Is it also possible to add a new slave to an existing stack product? Or is it necessary to recoregister the whole stack from scratch?

  2. If I coregister many pairs of Sentinel-1 images using the usual recommended steps, I end up with multiple stacks of two images (by the way, these stacks don’t have the “Master_bands” and “Slave_bands” metadata elements, as is the case for Stripmap). Is it possible to create a single stack product out of them?

  3. In what situations is Radar > Coregistration > Automatic Coregistration meant to be used, as opposed to InSAR Optimized Coregistration?

Many thanks in advance.


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Esteban, the InSAR optimized coregistration and Automatic coregistration
will eventually get merged. Currently you will need to use the Automatic
if you want a coregistered stack of GRDs.

It is possible to add a new slave to an existing stack by setting the
stack as the master product in the product set. However, it still needs
to write out a whole new stack product. We’re working on improving this.

Hi Luis, thanks for your immediate reply. Esteban

Hi Luis,

I’ve been running some additional tests with TSX data using InSAR Optimized Coregistration. It works OK but I see these messages in the terminal:

Graph parameter includeMaster not found for Operator CreateStack
Graph parameter includeMaster not found for Operator CreateStack
Graph parameter computeOffset not found for Operator CoarseFine-Coregistration

I think the graph given in InSARCoregistrationGraph.xml is outdated.


Is there a way to merge multiple 2-image Sentinel-1 stacks too? If I create a stack product (using the Create Stack op) with multiple 2-image stacks as input, the master gets copied multiple times, and the output .dim indicates the master is also a slave.

3 posts were split to a new topic: S1 IW slc: GC overhead error in back geocoding

Hi, I use SNAP 3.0. I want to realize InSAR Optimized Coregistration but I don’t find it

The different coregistration that existed before have been harmonized. It’s just the cross correlation based coregistraton.

Hello I would like to do a coregistration or stack for my GRD images (for Multi-Temporal speckle filtering) however when I do coregistration, some of the images are missing (there is no image if I open band) Some tips on what can be wrong?

My previous steps are: Apply orbit file -> Subset -> Thermal noise removal -> Calibration.)

Thank you for any suggestion!

could it be that these images were acquired from different tracks?

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You mean relative orbits? That’s good idea… I will try to explore it.

yes, I’d say so. Coregistration is sensitive to looking direction so it is likely that images from different orbits fail to find sufficient matching GCPs

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Thanks! I will test it during this week and provide the feedback here… :wink:

Yes! Thank you! For coregistration is necessary to use the same relative orbits!

There are two operators to make a stack iage
Create Stack
Sentinel TOPS coregisteration
The create stack tool doesn’t provide the option to choose reference DEM

But I am confused which one to use? I have multiple terrain corrected input products of the same area and I would like to stack them altogether/

Then Create Stack could be sufficient when. they habe identical geometry, otherwise you can apply the standard Coregistration tool from the menu which accounts for small shifts between the images.
S1 TOPS Coregistration only works on initial products in slant geometry, so you cannot use it.

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then,what’s the difference about Back Geocoding and Create Stack?I’m confused three of them a long time.

@oana_hogoiu @mfitrzyk I think the users would benefit from a flowchart explaining which co-registration to use when.