Automatic Identification System (AIS)

The Automatic Identification System (AIS) is an automated tracking system that displays other vessels in the vicinity. It is a broadcast transponder system which operates in the VHF mobile maritime band.

How It Works

AIS information is transmitted continuously and autonomously. It combines:

1. Static Data: Initialized at installation (MMSI, Call Sign, Name, IMO Number, Length, Beam).
2. Dynamic Data: From ship's sensors (Position, SOG, COG, Heading, Rate of Turn).
3. Voyage Related Data: Manually entered (Destination, ETA, Draft, Cargo Type).

Purpose in Maritime

• Collision Avoidance: Helps officers see other ships' movements and intentions.
• Vessel Traffic Services (VTS): Allows shore authorities to monitor traffic.
• Search and Rescue: AIS-SARTs can locate survival craft.
• Security: Maritime domain awareness.

Regulations

SOLAS requires AIS to be fitted aboard all ships of 300 gross tonnage and upwards engaged on international voyages, cargo ships of 500 gross tonnage and upwards not engaged on international voyages, and all passenger ships irrespective of size.