Processing JERS-1 data with SNAP

Dear colleagues,
I’d like to process JERS-1 data downloaded from ESA catalogue with SNAP.
Since this is my first experience with JESR-1 I’d like to have an opinion
on the interferometric processing of those data.
First I guess there are no orbit files so where I could download such for
the scene I have. Also are there any peculiarities this type of data.

Thank you.