User's Manual

1
1 WHAT IS AIS?
The Automatic Identification System (AIS) is a Very High Frequency (VHF) radio broadcasting system that
transfers packets of data over the VHF data link (VDL) and enables AIS equipped vessels and shore-based
stations to exchange identification information and navigational data. Ships with AIS transponders continually
transmit their ID, position, course, speed and other data to all nearby ships and shore stations. Such
information can aid greatly in situational awareness and provide a means to assist in collision avoidance.
AIS equipment is standardized by ITU, IEC, IALA and IMO and is subject to approval by a certification body. The
following AIS devices have been developed for variant applications.
 AIS Class A:
mandated by the IMO for vessels of 300 gross tonnages and upwards engaged on international voyages,
cargo ships of 500 gross tonnages and upwards, as well as passenger ships. It transmits typically on 12.5
watt output power.
 AIS Class B:
provides limited functionality and is intended for non-SOLAS commercial vessels and recreational vessels.
It transmits typically on 2 watt output power.
 AIS Base Station:
is provided by aids-to-navigation authorities to enable the ship to shore / shore to ship transmission of
information. Networked AIS Base Stations can assist in providing overall maritime domain awareness.
 AIS AtoN (Aids to Navigation):
provides an opportunity to transmit position and status of buoys and lights through the same VDL, which
can then show up on AIS-ready devices within the range.
 AIS SART:
Search and Rescue Transmitter using AIS can be used to assist in determining the location of a vessel in
distress. It is typically used on life rafts.
 AIS on Search and Rescue (SAR) Aircraft:
used on airplanes and helicopters to assist search and rescue operation.