IMO Performance Standards for AIS


Chapter V/ Regulation 19/ 2.4.5 of SOLAS 73/78 states that:
“AIS shall,

  • provide automatically to appropriate equipped shore stations, other ships and aircraft information, including ship’s identity, type, position, course, speed, navigational status, and other safety-related information;
  • receive automatically such information from similarly fitted ships;
  • monitor and track ships; and
  • exchange data with shore-based facilities.”

In addition to these Resolution MSC.74(69) includes Recommendation on

IMO Performance Standards for AIS, which are:


    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 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
    3. The installation of AIS should comply with the requirements of the Radio Regulations, applicable ITU-R Recommendations and General Requirements for Shipborne Radio Equipment Forming Part of The Global Maritime Distress And Safety System (GMDSS) And For Electronic Navigational Aids Resolution A.694 (17) 


  • 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 alternative 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,
      • a “polling” or controlled mode where the data transfer occurs in response to interrogation from a ship or competent authority.


    1. The AIS should comprise:
          1. 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 applications;
          2. a means of processing data from an electronic position-fixing system which provides a resolution of one ten thousandths of a minute of arc and uses the WGS-84 datum;
          3. a means to automatically input data from other sensors;
          4. a means to input and retrieve data manually;
          5. a means of error checking the transmitted and received data; and
          6. Built-In Test Equipment (BITE).
    1. The AIS should be capable of:
          1. providing information automatically and continuously to a competent authority and other ships, without the involvement of the ship’s personnel;
          2. receiving and processing information from other sources, including that from a competent authority and from other ships;
          3. responding to high priority and safety-related calls with a minimum of delay;
          4. providing positional and manoeuvring information at a data rate adequate to facilitate accurate tracking by a competent authority and other ships.

User interface
To enable a user to access, select and display the information on a separate system, the AIS should be provided with an interface conforming to an appropriate international marine interface standard.

For the purpose of ship and message identification, the appropriate Maritime Mobile Service Identity (MMSI) number should be used.

The information provided by the AIS should include:

  1. Static Information:
      1. IMO number (where available)
      2. Call sign & name
      3. Length and beam
      4. Type of ship
      5. Location of the position-fixing antenna on the ship (aft of bow and port or starboard of centreline)
  2. Dynamic Information:
      1. Ship’s position with accuracy indication and integrity status
      2. Time in UTC (Date to be established by receiving equipment.)
      3. Course over ground
      4. Speed over ground
      5. Heading
      6. Navigational status (e.g. NUC, at anchor, etc. – manual input)
      7. Rate of turn (where available)
      8. Optional – Angle of heel (if available)
        (Field not provided in basic message)
      9. Optional – Pitch and roll (if available)
        (Field not provided in basic message)
  3. Voyage related:
      1. Ship’s draught
      2. Hazardous cargo (type) (As required by competent authority)
      3. Destination and ETA (at Master’s Discretion)
      4. Optional – Route plan (Waypoints)
        (Field not provided in basic message)
  4. Short safety-related messages

Information update rates for autonomous mode
The different information types are valid for a different time period and thus need a different update rate:

  • Static information: Every 6 min and on request
  • Dynamic information: Dependant on speed and course alteration according to table given below
  • Voyage related information: Every 6 min, when data has been amended and on
  • Safety-related message: As required

Ship Reporting Capacity: 

The system should be able to handle a minimum of 2000 reports per min to adequately provide for all operational scenarios envisioned.

A security mechanism should be provided to detect disabling and to prevent unauthorised alteration of input or transmitted data. To protect the unauthorised dissemination of data, the IMO guidelines
(Guidelines and Criteria for Ship Reporting Systems (Resolution MSC.43(64))) should be followed.

Permissible Initialisation Period
The installation should be operational within 2 min of switching on.

Power Supply:

  •  The AIS and associated sensors should be powered from the ship’s main source of electrical energy.
  • In addition, it should be possible to operate the AIS and associated sensors from an alternative source of electrical energy.

Technical Characteristics of AIS
The technical characteristics of the AIS such as variable transmitter output power, operating frequencies (dedicated internationally and selected regionally), modulation, and antenna system should comply with the appropriate ITU-R Recommendations.

References for IMO Performance Standards for AIS: