errors in steps 1 with rectangular holes without PS points 'ix_0 = 0×1 empty double column vector'

[Fabio Brighenti]

Hello everyone, I am a PhD student and I am running for the project a PSI time series with stamps 4.1b in central sicily (italy), but I am having some difficulties. I have performed the data prcessing with SNAP 8.0.3 on two IW (2, 3) that I have then merged. The first set I am examining covers one year (2015). up to step 5 I am not experiencing prblems except for a warning of: 'ix_0 = 0×1 empty double column vector' in Step 1. But it manages to run all other steps. After Step 5 I run PS_plot('w') and I have the series of single interferograms but with rectangular holes smaller than the single patches.

I tried to change the value of amplitude dipsersion Da(3,6) to have more candidate PS, but the holes and the warnings remain.

I checked before following the export and the interferogrms are correct. 

How can I be sure that the export is successful?

Thanks for any idea you have.

P.S.

by processing the single separately IW there are no holes