...
Dclbydaplha - so it is S-AIS
The original concept of AIS was a LOS collision avoidance IIRC.
Depends whether you're on the AIS end or the SAT end 😉.
Your recollection is correct, IIRC it was originally developed for collision avoidance in coastal approaches and in to harbour. Like all technology its use gets extended. I am not aware of any modification required to a ship's AIS for it to be tracked by satellite. Best if it is a Class A unit though.