General Introduction; Description Of Ais - ACR Electronics NAUTICAST SAR AIS Installation Manual

1 General Introduction

1.1 Description of AIS

What does the abbreviation AIS stand for?
AIS stands for: "Automatic Identification System"
What is AIS?
According to IALA regulations, AIS is defined as follows:
Very simply, the 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 Self-Organizing Time Division Multiple Access (SOTDMA) technology to meet
these high broadcast rates and ensure reliable and robust ship to ship operation.
What are the performance standards of AIS?
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
- Utilization of maritime VHF channels
Which modules make up an AIS-Transponder?
The Modules:
- DGPS / GPS receiver
- VHF Radio
- Antenna
- Computer (CPU)
- Power Supply
Appropriate application software connects the individual modules.
In which modes does AIS function?
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;
- A "polling or controlled" mode, where the data transfer occurs in response to
interrogation from a ship or competent authority.
Installation Manual
1
Y1-03-0208 Rev.A