Originally Posted by
OCTA Aus
The reason the radar separation standard is 5NM is because it has to allow for the errors in the system. At a guess I would assume the SSR radars are accurate to within 2NM. Therefore at 5NM apart by radar you should still be 1NM apart even if both radar positions are at the extremes of their errors. So yes, I’m not surprised that an aircraft was on the opposite side to what the radar said. The raw RADAR feed that goes into Eurocat actually is quite a mess, it goes through many filters and radar processors before it goes onto the control display.ADSB would likely be far more accurate, I believe it broadcasts position twice every second. However the position symbol in the control system will still only update once every 5 seconds.
Eurocat HMI air situation display updates every 200ms. I don't believe there is a five second update cycle anywhere else in the chain.