Three-Pass Differential Interferometry

Hello everyone!!

I was reading the documentation (in the “Help” of SNAP) related to the Three-Pass DInSAR and I have a question about what of the two pairs (defo or topo) is necessary to unwrap.
At the second paragraph of the text it can be read that “This step can be performed only if an unwrapped topography interferogram (topo pair) and a complex deformation interferogram (defo pair) are present.” At the fourth paragraph, the pair that is said to unwrap changes “Then we have to unwrap defo-pair. In order to do so, the deformation pair has to be selected, and extracted for the external unwrapping in the Snaphu software.” and, finally, at the part that talks about the Source Products changes again the pair that is necessary to unwrap:

Source Products are stack of:

  1. Defo-pair: Interferometric product containing bands of so-called defo-pair. See operator description for more details.
  2. Topo-pair: Interferometric product containing bands of so-called topo-pair. Topo-pair interferogram has to be unwrapped, and stored as ‘real’ data band. See operator description for more details.

Someone could help me with this, please? I am really confused in the methodology that is necessary to follow to obtain a single DEM product with three SAR images. Thanks!!

Best regards,
Eduardo Ramos.

1 Like

Hi Eduardo Ramos,
I have met the problem as you.If you have sloved it ,could you tell me the solution. I don’t know 3 pass DInSAR technological process ,if you know ,could you tell me how to operation. I will appreciate any comment. Thank you.

Hi Sky,
I haven’t found any solution for this yet, I have to say that I haven’t done many test with this issue, but I think is a competence from the developers to change the ambiguous documentation in this part.

Sorry I can’t help you more

OK , thank you all the same .

If anyone find solution, please let us informed.