About CSK displacement analysis in SNAP

Microwave Toolbox
#1

Hi,

I am working wiht a pair of CSK StripMap (HIMAGE) products for displacement analysis. The processing chain I have ahead is:

  • Corregistration
  • Interferogram formation (removing flat earth and topo)
  • Phase filtering (Goldstein)
  • Phase Unwrapping (snapu export, processing and import)
  • Phase to displacement
  • TC of displacement

After checking some of the CSK relevant guides mentioned on this forum (here and here), I have couple of questions on the first two steps (corregistration and interferogram):

When doing Corregistration with the following parameters:

image

image

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The result looks like this:

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image937×640 319 KB

I have seen in other posts on this forum that default parameters can be left. However the presence of yellow and blue in my stack make make think that corregistration is not good enough? Any comments on this or recomendation for CSK products?

Take that corregistration as input, I create my ifg (Trying to match the DEM resolution as much as possible to the data resolution)

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Resulting on (showing full extent)

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image861×862 249 KB

Well, I dont see any fringes or patterns so I am thinking something went wrong. Any advice until this point on my chain?

Thanks

#2

Looks like the coregistration has not been successful enough.

#3

Playing with the paremeters to see if I can get it better. Based on this answer too – Cosmo SkyMed coregistration with SNAP

Any recomendation?

#4

I’d recommend more GCPs (e.g. 5000), and a smaller window size for fine registration (16)

#5

Thanks. Tried already with even more GCP (I put 20000 - maybe way too much) and the ifg was still bad. Trying now with your feedback. In other paramter to which I should pay more attention?

#6

you can also increase the GCP tolerance a bit (0.2)