What is the quality of Coregistration?

I am using SNAP for interferometric processing to estimate glacial movements. I understand the quality of my outputs greatly rely on the quality of coregistration of the master and slave.

Is there any way to get the quality (quantitative) of coregistration? May be in form of residuals or RMSE?

you can check “Show Residuals” in the coregistration tool


This outputs how many GCPs are left after all iterations that fulfill the required correlation criteria.

Strangely, the S1 TOPS Coregistration doesn’t have this checkbox. But if you open a coregistered product, you can select “InSAR Stack Overview” to retrieve the same information: grafik

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I am using SLC-IW products of S1a &b. So, to coregister my chosen pair, I use S1 TOPS Coregistration. As mentioned by you, I located the InSAR Stack for overview but the ‘Coregistration Residuals’ section doesn’t show anything (screenshot attached ). I wonder why. The ‘Stack information’ section has the names of 2 products that have been stacked together. What could be the problem in this case?

you are right - I tested it and don’t see any as well. Sorry, I just expected the information would be there.

You can apply TOPS Split and Deburst and perform the “normal” coregistration on the outcomes just to get a coarse Idea on the correctness. For interferometry I would still proceed with the TOPS coregistered product.

That’s alright. And thanks for trying it out yourself. I shall get the residuals from ‘normal’ co-registration option. That should help me get an idea, but I may not be able to report them in a document. :frowning:

I know - not very scientific… :smirk: