Problem with the final steps of interferometry

Hello everyone, Im working recently with interferometry, but I don’t understand something in the results, Could anyone help me? Thanks in advance

I chose two images from Mocoa Colombia (there was a landslide and it left 300 dead people on march 31)

My two images are 12 days apart and are 36.95m apart.

I chose the polarisations VV

And this is my interferogram

And this is Mocoa (The white square) and the landslide’s zone… at North East from there (blue part)

Apparently all is fine, so in my next step I unwrapped the Phase and create the displacement layer.

My problem with this image (the displacement) is: that is different from the interferograma and I see a degradation of colors, a scale not a patron, I assumed that mocoa should be seen or highlighted over the other parts, but it’s no clear for me.

And this is Mocoa:

This is fine?? All the displacement is positive, yes I know the vegetation is too dense as well the rain (The images are 20 march and 1 april, the landslide occurred on March 31)

I try a new pair, again, the images are from the 20 march and the new image April 25
Here is the interferogram.

Again in the displacement I see a color scale not a patron (I chose a bad gradient to remark this)

And this is the displacement of mocoa

So, I try again but with another orbit, a descent orbit. My images are from March 27 and April 08.

And this is the displacement

Tell me what do you think? Is fine, there was a problem with the final step? Or maybe the color scale?

Thanks for your help.

If the displacement has such as strong ramping I believe that the orbit files are not exact enough so an overall trend is misguidingly superimposing the displacement patterns.

Thanks Andreas for your answer.


  • When I choose the orbits, I choose the same orbit and, in the overview The modeled coherence, the distance between the orbits It’s the recommended in the tutorials, guides and some comments that I read
  • When I see my interferogram, It’s apparently good. Im wrong?
  • All my interferograms have the same behavior, The interferogram is clear, but the displacement is different.

What do you recomend me? I should try with another zone?, maybe more distance between dates?

hard to tell actually. What is the perpendicular baseline between your images?

According to overview: -36.95

that leaves quite litte space for errors in the orbit state vectors. Would be worth a try with a larger baseline but I can’t promise that the results will be better, as atmosphere and other factors still play a role. I had similar problems here: The Order of DEM Creating Steps

Thanks again, I’ll Ckeck your post, maybe I get some hint