I try to make interferograms with S1a data in SNAP 3.0. I follow the TOPS Interferometry tutorial for S1a from May 2015. It is working, so that I get an interferogram. But I have still stripes after running the debursting step and at the end after the goldstein filtering I have these phase jumps between the subswaths and the bursts.
My preprocessing chain is: Import Sentinel 1 > S1 TOPS Coreg. (3x (for each sub swath)) > Interferogramm formation > (3x (for each sub swath)) > 3x debursting > merging > topo phase removal > goldstein filtering.
I have here a zoomed screenshot after the debursting step of the first subswath:
I try to understand, why I have still these effects. Can somebody help me? Do I have to run the radiometric calibration before the coreg. process? Or is it included in this process?
Thank you very much in advance.
It should be possible to remove these by using the Spectral Diversity step before interferogram formation (Open products -> TOPSAR split -> apply orbit files -> back geocode ->Enhanced Spectral Diversity etc…) . However when I have tried to use this it hasn’t actually made any difference to the stripes. Does it work for you?
thanks for replying. I just try this way. But I I thought if I choose the S1 TOPS Coreg. method, that all these steps like split, apply orbit file, back geocoding and esd would have been included.
I let you know, if I have results.
@HHVice I am in the same situation and have this problem for almost all of the pairs I am using. I have not been able to remove the stripes and have posted this problem a few times but not heard any other suggestions. Does anybody have any advice?
@amylauraparker I also have tried several ways. SNAP 2.0, 3.0, Coreg with or without ESD,… I can not produce images without these stripes like in the tutorial from the esa. I found many papers concerning producing ifgs from the IW mode from S1a and in every paper it is mentioned, that the ESD step is important. But for me it did not work.
If you have precise orbits, the TOPS backgeocoding with ESD should be able
to precisely coregister the data so that you may produce an interferogram
without phase jumps. However, phase jumps can still occur in scenes where
there is movement or an atmospheric component to the signal.
Thanks @lveci. Unfortunately it seems in many cases the ESD is failing to make a difference and that even with the precise orbits the phase jumps still occur due to TOPS mode acquisition rather than a deformation/atmospheric component. I’ve found that they often occur when the coverage of the swath has been adjusted slightly. Do you have any other suggestions of things to try? Speaking to other colleagues I know this is an issue with GMT5SAR GAMMA etc also.
thanks for the troubleshooting and all the efforts on that.
But I stay now with GMT5SAR, which is also 4free to use and until yet I have no phase jumps at all.
Is this this issue, which you have found, an error in general in the code?
I’m sorry, I know it’s been a while since you posted this, but I am experiencing the same problems of incoherence between bursts in my interferograms and I would like to try your solution, could you please help me? This is my processing chain: