Starport and planetary authorities may cooperate, but they are separate entities, possibly quite a number, if they suffer balkanization.
At least in the Imperium.
Planetary authorities might not care, so the sensors are one, possibly two, technological levels below stated; they're paranoid, so they could be one, possibly two, technological levels higher than stated, with matching weapon systems and platforms.
I think Imperium starports would default to technological level twelve, higher for more important facilities, unless for some reason they've had to make due with a lower technological level one, as the budget was busted for the year, and they had the technical department jerry build one from available parts.