Azimuth Shift Issue?

Microwave Toolbox Problem Reports
#1

Hi,

I run into a problem which might be caused by azimuth shift.

DATA Used:

  1. S1A_IW_SLC__1SDV_20151003T101952_20151003T102020_007987_00B2BB_43B7.zip
  2. S1A_IW_SLC__1SDV_20151015T101952_20151015T102020_008162_00B76C_DB95.zip

XML file used for co-registration:
china.xml (8.7 KB)

Interferogram got:

Screenshot from 2015-10-30 13:34:29.png994×707 1.9 MB

Best regards,

Speeder
SkyGeo B.V.

#2

Hi, we have processed the data that you had used, but we could not repeat the problem that you reported. Is the vertical line (or gap) in your interferogram at the boundary of subswaths? If yes, it could be caused by an old bug in S1 Merge which has already been fixed in Beta8. Are you using Beta8? By the way, we did notice phase jump in the interferogram and that could be caused by the inaccuracy of the orbit. Since no precise orbits are available for the products, we did not include Apply Orbit File processing step in our processing chain.

#3

Hi, thanks for the answer. I am working in the same team, so I can add some info:

The problem we are trying to solve is the phase jump.
The vertical line is just a rendering problem, it changes for different zoom levels.
We are running the tool in Ubuntu 14.04.
We are always building SNAP from sources, the version we used to process these images is a build from 22/10/2015.

Aníbal Rivero
SkyGeo B.V.

#4

Have you used range/azimuth shifts under S-1 TOPS coregistration?

#5

Hi, we applied the azimuth shift operator. Speeder attached the graph in the initial post. You can find all operators there.

Esteban
Skygeo

#6

Hi,

I downloaded the precise orbit files and applied them for both of the SLC I used. And now, this is the updated results. The phase jump seems to be disappeared. Thanks for your help!

Pasted image1181×700 2.63 MB

Best regards,

Speeder
SkyGeo B.V.