The bipolar outflows themselves are probably oriented by the magnetic fields.
Once detected, this difference is correlated by computers, and a composite signal is created.
Radio waves from the same object reach the separate dishes at slightly different times.
It seems clear that the magnetic fields have a key role in all of this, even though many of the details are not well understood.
From Jack Welch "On-Camera" & Baselines In Interferometry: Correlation of Two Signals
Once detected, this difference is correlated by computers, and a composite signal is created.
Radio waves from the same object reach the separate dishes at slightly different times.
It seems clear that the magnetic fields have a key role in all of this, even though many of the details are not well understood.
From Jack Welch "On-Camera" & Baselines In Interferometry: Correlation of Two Signals