ACR Electronics ACR-AIS-300 Manual De Usuario
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Y1-03-0222 Rev T4T4
1. WHAT IS AIS?
AIS stands for Automatic Identification System. AIS increases navigational safety and collision avoidance by
transmitting vessel identification, helping to reduce the difficulty of identifying ships when not in sight (e.g. at
night, in radar blind arcs or shadows or at distance) by broadcasting navigational intentions to other vessels by
providing ID, position, course, speed and other ship data with all other nearby ships and land based stations.
According to IALA regulations, AIS is defined as follows:
AIS is a broadcast Transponder system, operating in the VHF maritime mobile band. It is capable of sending
ship information such as identification, position course, speed and more, to other ships and to shore. It can
handle multiple reports at rapid update rates and uses Carrier Sense Time Division Multiple Access (CSTDMA)
technology to meet these high broadcast rates and ensure reliable and robust ship to ship operation.
The IMO defines the performance standards as follows:
transmitting vessel identification, helping to reduce the difficulty of identifying ships when not in sight (e.g. at
night, in radar blind arcs or shadows or at distance) by broadcasting navigational intentions to other vessels by
providing ID, position, course, speed and other ship data with all other nearby ships and land based stations.
According to IALA regulations, AIS is defined as follows:
AIS is a broadcast Transponder system, operating in the VHF maritime mobile band. It is capable of sending
ship information such as identification, position course, speed and more, to other ships and to shore. It can
handle multiple reports at rapid update rates and uses Carrier Sense Time Division Multiple Access (CSTDMA)
technology to meet these high broadcast rates and ensure reliable and robust ship to ship operation.
The IMO defines the performance standards as follows:
-
Ship to ship working , ship to shore working, including long range application , automatic and
continuous operation , provision of information messaging via PC and utilization of maritime VHF
channels
continuous operation , provision of information messaging via PC and utilization of maritime VHF
channels
The Modules: GPS system, VHF Radio, Antenna, and the Data Power Cable
(Appropriate application software connects the individual modules).
AIS are required to function flawlessly in a variety of modes. The relevant regulations require:
The system shall be capable of
(Appropriate application software connects the individual modules).
AIS are required to function flawlessly in a variety of modes. The relevant regulations require:
The system shall be capable of
- An
"autonomous and continuous" mode for operation in all areas. This mode shall 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;
authority;
- A
"polling or controlled" mode, where the data transfer occurs in response to interrogation from a
ship or competent authority.
This illustration depicts a typical AIS System, where two or more AIS equipped vessels (and shore based
systems) are automatically communicating with each other.