Here's an interesting tidbit from that article:
It’s primary asset is an X-band multimode AESA radar, supplemented by L-band radars said to be capable of bouncing signals off opposing stealth aircraft.
Such a radar would give a general indication of where the ‘enemy’ is. The T-50s pilot would then fall back on infra-red and optical sensors to pick it out of the sky.
Problem is, a passive ESM system is going to detect the active system's emissions way before the active system will pick up any returns. That will give the stealthy aircraft (presumably F-35) a big advantage assuming it has a long range internal carriage missile. Is AMRAAM long range enough? Or will F-35 have to wait till the Meteor is fielded? Even if F-35 will be dependent on Meteor, it seems highly likely that Meteor will get fielded well before T-50 gets fielded. Which would seem to indicate AMRAAM will be long range enough for some time.