Back-geocoding // Same polarization

damianvz · August 3, 2021, 3:52am

Hey guys, im trying to run the coreg_ifg_topsar.py for the corregistration and interferogram formation. But when i run the code, the terminal shows this error (Snap v8.0.5 // ubuntu 18.04 LTS):

INFO: org.esa.snap.core.util.EngineVersionCheckActivator: Please check regularly for new updates for the best SNAP experience.
Executing processing graph
INFO: org.hsqldb.persist.Logger: dataFileCache open start
Same polarization is expected.
done.
Error: [NodeId: Back-Geocoding] Same polarization is expected.

Also i check my 18 files with same path and frame and i replace the line 49 in both files with (computation and computation_subset):

  <useSuppliedRangeShift>false</useSuppliedRangeShift>
  <useSuppliedAzimuthShift>false</useSuppliedAzimuthShift>

Path: 156 - 156
Frame: 712 - 712
File Types: SLC
Beam Modes:
IW Polarizations: VV+VH
Flight Dir:Descending
Dataset: SB

I hope maybe someone can help me. Regards!

damianvz · August 3, 2021, 3:53am

i use the VV polarization for the master and the slaves images

ABraun · August 3, 2021, 12:44pm

did you actively select it during TOPS Split?

damianvz · August 3, 2021, 2:54pm

The master image [1] with the grap builder (read–apply orbit–topsar split (burst 8-9 iw2)–write).
The slaves images [2] [ with the splitting_slaves.py (but in this case shows all burst)

ABraun · August 3, 2021, 6:41pm

the error message arises because the master still has VV and VH. Please remove VH from the stack (don’t forget to save) and use this as the reference product in your processing.

damianvz · August 3, 2021, 8:29pm

yes sr, i nedded process again and works fine, thanks you. I have a Q related, when i run the codes, terminal shows this:

Executing processing graph
INFO: org.esa.s1tbx.io.sentinel1.Sentinel1Level1Directory: Less than 8K RAM. Using FileCacheImageInputStream

i can process but i dont know why appears this info message.

Any idea?

ABraun · August 4, 2021, 5:40am

Maybe your computer does Not have enough RAM. Did you reduce the bursts as much as possible during TOPS Split?

damianvz · August 4, 2021, 5:43pm

Yes, I complete the entire process succes I think. Thanks a lot for you support . Now im gona try apply the stamps visualizer in rstudio. I spend a lot of hours because im no native english and linux user.

Regards.