Automatic Identification System (AIS)

The automatic identification system (AIS) is an automatic tracking system that uses transponders on ships and is used by vessel traffic services (VTS). Originally designed as a terrestrial communication system, satellites are now also used to passively capture the signal traffic. With a few exceptions, AIS traffic is in the form of continual status announcements of a sender to all interested parties in its proximity. AIS information supplements marine radar, which continues to be the primary met