You didn’t get me I guess, AWACS and other nearby supporting aircrafts or the air defences or in case of off shore air battle, then Naval radars actively send input or stimulus to satellite, Which in turn forwards to missile system computer...
I might be wrong theoretically but this is by far what I made up of that...
I guess once this PL-1X launches, It has no relation with the platform, rather it is independent but during mid course, it recieves updates while satellite which in turn gets update via data link.