Performance Standards – AIS

Automatic Identification System (AIS) is a system which provides a means whereby ships exchange information such as ID, position, course, speed etc, with all other ships in vicinity ans shore stations. IMO has specified performance standards for AIS fitted on ships, these performance standards help avoid sub standard ships and avoid accidents at sea.

AIS is basically a shipboard broadcast transponder system by which continually transmit their vital data, to all other ships in vicinity and shore stations on common VHF Radio channel. Working of AIS is explained in detail in other article. Let us understand what are the performance standards for AIS as per IMO


These performance standards specify the requirements for the universal AIS:

  1. The AIS should improve the safety of navigation by assisting in the efficient navigation of ships, protection of the environment, and operation of Vessel Traffic Services (VTS), by satisfying the following functional requirements:
    - in a ship-to-ship mode for collision avoidance;
    - as a means for littoral States to obtain information about a ship and its cargo; and
    - as a VTS tool, i. e. ship-to-shore (traffic management).
  2. The AIS should be capable of providing to ships and to competent authorities, information from the ship, automatically and with the required accuracy and frequency, to facilitate accurate tracking. Transmission of the data should be with the minimum involvement of ship's personnel and with a high level of availability.
  3. The system should be capable of operating in a number of modes:
    - an "autonomous and continuous" mode for operation in all areas. This mode should be capable of being switched to/from one of the following alternate modes by a competent authority;
    - an "assigned" mode for operation in an area subject to a competent authority responsible for traffic monitoring such that the data transmission interval and/or time slots may be set remotely by that authority; and
    - a "polling" or controlled mode where the data transfer occurs in response to interrogation from a ship or competent authority.
  4. The AIS should comprise:
    - a communication processor, capable of operating over a range of maritime frequencies, with an appropriate channel selecting and switching method, in support of both short and long range
    - a means of processing data from an electronic position-fixing system which provides a resolution of one ten thousandth of a minute of arc and uses the WGS-84 datum;
    - a means to automatically input data from other sensors meeting the provisions as specified in paragraph;
    - a means to input and retrieve data manually;
    - a means of error checking the transmitted and received data; and
    - built in test equipment (BITE).
  5. The AIS should be capable of:
    - providing information automatically and continuously to a competent authority and other ships, without involvement of ship's personnel;
    - receiving and processing information from other sources, including that from a competent authority and from other ships;
    - responding to high priority and safety related calls with a minimum of delay;
    - providing positional and maneuvering information at a data rate adequate to facilitate accurate tracking by a competent authority and other ships.
    - monitoring and tracking targets
    - handling at least 2000 reports per minute
    - being operational within two minutes of switching on
  6. For the purpose of ship and message identification, the appropriate Maritime Mobile Service Identity (MMSI) number should be used.
  7. The information provided by the AIS should include
    A] Static:
    - IMO number (where available)
    - Call sign & name
    - Length and beam
    - Type of ship
    - Location of position-fixing antenna on the ship (aft of bow and port or starboard of centerline)
    B] Dynamic:
    - Ship's position with accuracy indication and integrity status
    - Time in UTC *
    - Course over ground
    - Speed over ground
    - Heading
    - Navigational status (e.g. NUC, at anchor, etc. - manual input)
    - Rate of turn (where available)
    - Optional - Angle of heel (where available)
    - Optional - Pitch and roll (where available)
    B] Voyage related:
    - Ship's draught
    - Hazardous cargo (type)
    - Destination and ETA (at masters discretion)
    - Optional - Route plan (waypoints)
    C] Short safety-related messages
  8. AIS and its associated sensors shall be supplied with main emergency source of power.
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