Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.917(22) – Guidelines for the Onboard Operational Use of Shipborne Automatic Identification Systems (AIS) – (Adopted on 29 November 2001) - Annex - Guidelines for the Onboard Operational use of Shipborne Automatic Identification Systems (AIS) - AIS Information Sent by Ships - Ship’s data content
Ship’s data content
11. The AIS information transmitted by a ship is of three different types:
- fixed or static information, which is entered into the AIS on installation and need only be changed if the ship changes its name or undergoes a major conversion from one ship type to another;
- dynamic information, which, apart from ‘Navigational status’ information, is automatically updated from the ship sensors connected to AIS; and
- voyage-related information, which might need to be manually entered and updated during the voyage.
12. Details of the information referred to above are given in Table 1 below:
Data sent by ship
| Information item | Information generation, type and quality of information |
| Static | |
| MMSI | Set on installation |
| (Maritime Mobile Service Identity) | Note that this might need amending if the ship changes ownership |
| Call sign and name | Set on installation |
| Note that this might need amending if the ship changes ownership | |
| IMO Number | Set on installation |
| Length and beam | Set on installation or if changed |
| Type of ship | Select from pre-installed list |
| Location of position-fixing antenna | Set on installation or may be changed for bi-directional vessels or those fitted with multiple antennae |
| Dynamic | |
| Ship’s position with accuracy indication and integrity status | Automatically updated from the position sensor connected to AIS |
| The accuracy indication is for better or worse than 10 m. | |
| Position Time stamp in UTC | Automatically updated from ship’s main position sensor connected to AIS |
| Course over ground (COG) | Automatically updated from ship’s main position sensor connected to AIS, if that sensor calculates COG |
| This information might not be available | |
| Speed over ground (SOG) | Automatically updated from the position sensor connected to AIS |
| This information might not be available | |
| Heading | Automatically updated from the ship’s heading sensor connected to AIS |
| Navigational status | Navigational
status information has to be manually entered by the OOW and changed as
necessary, for example:
|
| In practice, since all these relate to the COLREGs, any change that is needed could be undertaken at the same time that the lights or shapes were changed | |
| Rate of turn (ROT) | Automatically updated from the ship’s ROT sensor or derived from the gyro |
| This information might not be available | |
| Voyage-related | |
| Ship’s draught | To be manually entered at the start of the voyage using the maximum draft for the voyage and amended as required |
| (e.g. – result of de-ballasting prior to port entry) | |
| Hazardous cargo (type) | To be manually entered at the start of the voyage confirming whether or not hazardous cargo is being carried, namely: |
| DG (Dangerous goods) | |
| HS (Harmful substances) | |
| MP (Marine pollutants) | |
| Indications of quantities are not required | |
| Destination and ETA | To be manually entered at the start of the voyage and kept up to date as necessary |
| Route plan (waypoints) | To be manually entered at the start of the voyage, at the discretion of the master, and updated when required |
| Short safety-related messages | |
| Free format short text messages would be manually entered, addressed either a specific addressee or broadcast to all ships and shore stations |
13. The data is autonomously sent at different update rates:
- dynamic information dependent on speed and course alteration (see Table 2),
- static and voyage-related data every 6 minutes or on request (AIS responds automatically without user action).
Report rate of dynamic information
| Type of ship | General reporting interval |
| Ship at anchor | 3 min |
| Ship 0-14 knots | 12 sec |
| Ship 0-14 knots and changing course | 4 sec |
| Ship 14-23 knots | 6 sec |
| Ship 14-23 knots and changing course | 2 sec |
| Ship >23 knots | 3 sec |
| Ship >23 knots and changing course | 2 sec |
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