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.