User's Manual
Table Of Contents
- Safety summary
- Preface
- Training information
- About this manual
- Introduction
- Installation
- Interface description
- Configuration
- Service & maintenance
- Technical specifications
- NMEA sentences
- B.1 NMEA sentences used
- B.2 Sentence use reference
- B.2.1 ABK - AIS addressed and binary broadcast acknowledgement (output)
- B.2.2 ABM - AIS addressed binary and safety related message (input)
- B.2.3 ACA - AIS channel assignment message (input / output)
- B.2.4 ACK - Acknowledge alarm (input)
- B.2.5 AIR - AIS interrogation request (input)
- B.2.6 ALR - Set alarm state (output)
- B.2.7 BBM - AIS broadcast binary message (input)
- B.2.8 DTM - Datum reference (input)
- B.2.9 EPV - Command or report equipment property value (input / response output)
- B.2.10 GBS - GNSS satellite fault detection (input)
- B.2.11 GGA - Global positioning system (GPS) fix data (input)
- B.2.12 GNS - Fix data (input)
- B.2.13 HBT - Heartbeat supervision sentence (input)
- B.2.14 HDT - Heading true (input)
- B.2.15 LR1 - AIS long-range reply sentence 1 (output)
- B.2.16 LR2 - AIS long-range reply sentence 2 (output)
- B.2.17 LR3 - AIS long-range reply sentence 3 (output)
- B.2.18 LRF - AIS long-range function (input / output)
- B.2.19 LRI - AIS long-range interrogation (input / output)
- B.2.20 NAK - Negative acknowledgement (output)
- B.2.21 PTHRAOC - AIS operational control (input / output)
- B.2.22 PTHRROS - Radio operational status (output)
- B.2.23 RMC - Recommended minimum specific GNSS data (input)
- B.2.24 ROT - Rate of turn (input)
- B.2.25 SPW - Security password sentence (input)
- B.2.26 SSD - AIS ship static data (input / output)
- B.2.27 THS -True heading and status (input)
- B.2.28 TRL - AIS transmitter non functioning log (output)
- B.2.29 TXT - Text transmission (output)
- B.2.30 VBW - Dual ground/water speed (input)
- B.2.31 VDM - AIS VHF data-link message (output)
- B.2.32 VDO - AIS VHF data-link own-vessel report (output)
- B.2.33 VER - Version (output)
- B.2.34 VSD - AIS voyage static data (input / output)
- B.2.35 VTG - Course over ground and ground speed (input)
- B.2.36 ZDA - Time and Date (output)
- Supported keys
- Glossary
- Index
Introduction to AIS
2-2 Chapter 2: Introduction 98-137573-A
2.1.2 AIS applications and purpose
The principal applications of AIS are:
• Information exchange between vessels within VHF range of each other, increasing
situation awareness
• Information exchange between a vessel and a shore station, such as a Vessel Traffic
Service (VTS), to improve traffic management in congested waterways
• Automatic reporting in areas of mandatory and voluntary reporting
• Exchange of safety related information between vessels and between vessels and shore
station(s).
The purpose of AIS is to improve the safety of navigation and protection of the
environment by assisting in the effective navigation of ships and the operation of VTS. This
is achieved through the following:
• In a ship-to-ship mode for collision avoidance
• As a means for littoral states to obtain information about a ship and its cargo
• As a VTS tool, i.e. ship-to-shore, for traffic management
• Increased situational awareness which enables effective response to emergencies such
as search and rescue (SAR) as well as environmental pollution
• Providing data to identify trends or improvements to enhance navigational safety.
If a vessel operating in a mandatory ship reporting system does switch off its AIS, this
should be reported to the relevant authority. Note that some data is entered or updated
manually, meaning that there is potential for false entry and for the entered data to
become out of date. This includes data related to static information (e.g. ship identity,
dimension) and voyage related data (e.g. navigational status).
AIS and radar
A difference between AIS and radar is that AIS uses an absolute referencing system to
determine the position, whereas radar determines the position by relative measurements
from the vessel or shore base to observed targets. AIS may be used together with radar
information to provide:
• Vessel identification, heading, course over ground (COG) and speed over ground (SOG)
• Improved vessel tracking (no target swap)
• Wider geographical coverage
• Greater positional accuracy, dependent on the position input sensor
• Information in radar shadow area ('sees' around bends and behind islands)
• Maneuver data in nearly real time
• No loss of targets in sea, rain and snow clutter
Note
Not all ships are required to have AIS. Furthermore, AIS may
be switched off if there is a potential risk that the operation of
AIS might compromise the safety or security of the ship, or if
security incidents are imminent.