Interferogram looks like a noise

Microwave Toolbox Problem Reports
#1

I analyse ground deformations within mining areas. Using computer which parameters I listed above I have already processed a lot of Sentinel-1 images of studied region and I have obtained good interferograms. However, during processing S-1 images that were acquired in June 2016 I met a lot of problems. The most important one concerns obtained results. The whole interferogram looks like noise (see attached figure). What can be the reason of such results? I have processed the same pair of S-1 images three times and I always obtained the same results.

Processing chain: (Import SAR Sensors Sentinel 1 -> S1 TOPS Coregistration (IW1, bursts: 1-9) -> Interferogram formation -> Deburst )

#2

I have a similar problem. Do you find why that happening?
Thanks a lot!

#3

It all depends on how good both images are correlated.

  • Was the coregistration correct? Check if both images are correctly aligned with an RGB image
  • Do you have sufficient coherence in your area of interest?
  • Is the temporal difference small enough?
  • Is the perpendicular baseline suitable?
#4

Hello ABraun and thank you for your reply!

The coregistration was successful, I check it with the RGB image.
My temporal difference 132 days, and my perpedicular baseline 69m

#5

still, temporal decorrelation remains as one possible error source. 132 days is quite long, especially over vegetated areas.
Did you have a look at the coherence? It should be at least 0.3 in the regions you are interested in and be composted of larger, connected areas.

#6

The area of interest is big, so the coherence is not good. Thank you for your help and for learning me to check my coregistration!!!