Topographic Phase Removal

Dear friends
If we want to get displacements, we should delete topography part (DEM). I think it should be possible by ‘Topographic Phase Removal’ in TOPS Interferometry Tutorial´. Page 17.
Am I right?


Please take a look at this


Dear Fallah
Thank you so much for great powerpoint. I know if we want to get displacement, we should delete topography (elevation) phase but I do not know does SNAP toolbox do it or not by this order ‘Topographic Phase Removal’ in ‘TOPS Interferometry Tutorial’. Page 17.
Please look at ‘TOPS Interferometry Tutorial’.
MajanTOPS Interferometry Tutorial.pdf (2.3 MB)


I already mentioned the processing chain using SNAP, you could find it here Deformation in Volcano with InSAR

Dear Falah
I saw the processing with the next steps:

  1. Import the images
  2. Co-registration: here I selected IW2 and the bursts 3 and 4
    3.Create the interferogram
  3. Made the deburst
  4. Remove the topographical phase
  5. Applied the Goldstein Phase Filtering
  6. Unwrapping
  7. Geocode
    As I am using ‘TOPS Interferometry Tutorial’, it does not have two last processes ( I mean I do not know how I must do 6.Unwrapping and 7.Geocode). Would you guide me?

one lesson
good site for other sar fings also

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Here is an easy way to unwrap the phase

you need to install CygWin which is a Linux emulator and then download SNAPHU from


Could you please tell me why do we need to remove the topographic phase?

The interferometric phase you calculate has many contributions like : phase related to “flat earth” , displacement, topography, atmoshpere and noise. If you want to retrieve from your interferogram only the deformation you need to remove all the other phase components. Sometimes we can neglect some components but in general case if you want to retrieve deformation you need to remove the component related to topography.