Data aggregated this way can be viewed on any internet-capable device to provide near global, real-time position data from anywhere in the world. The purpose of the access scheme is to offer an access algorithm which quickly resolves conflicts without intervention from controlling stations. Electronic navigation Navigational equipment Maritime communication Maritime safety Technology systems Water transport Aids to navigation. However, the audio output from the radio would need to be then decoded.

This will not affect users, but system builders need to upgrade software to accommodate the new standard. It weighs six kilograms and is shaped like a cube. Each frame is divided into slots.

This is generally done for the first transmission slot, or for messages of a non-repeatable character. This system was built between and and was delivered by Saab TranspondereTech. Port authorities or other shore-based facilities may be equipped with receivers only, windows 8-usb-dvd-tool so that they can view the local traffic without the need to transmit their own location. Timing is vital to the proper synchronization and slot mapping transmission scheduling for a Class A unit. This allows a device to pre-announce its allocations for autonomous and continuous operation.

Most mandates are focused on commercial vessels, with leisure vessels selectively choosing to fit. Currently ad-hoc networks exist with class A mobiles.


In the event of system overload, only targets further away will be subject to drop-out, in order to give preference to nearer targets, which are of greater concern to ship operators. From Wikipedia, the free encyclopedia. The purpose of the satellite is to improve surveillance of maritime activities in the High North.


This article is about vessel tracking. Although the data output format supports heading information, in general units are not interfaced to a compass, so this data is seldom transmitted. For inland waterways transmission identification, see Automatic Transmitter Identification System marine. In this way new stations, including those stations which suddenly come within radio range close to other vessels, will always be received by those vessels. Redirected from Automatic Identification System.

The message reports a precise position and time. Therefore, every unit is required to have an internal time base, synchronized to a global navigation satellite system e. One of the biggest fully operational, real time systems with full routing capability is in China.

It serves as a static reference for other ships. In practice, the capacity of the system is nearly unlimited, allowing for a great number of ships to be accommodated at the same time. Typical data includes vessel name, details, location, speed and heading on a map, is searchable, has potentially unlimited, global range and the history is archived. Used by an aircraft helicopter or airplane which is involved with search and rescue operation on the sea i.

In other projects Wikimedia Commons. This information includes static data such as a ship's length, width, draught, as well as the ship's intended destination.

In order to make the most efficient use of the bandwidth available, vessels that are anchored or moving slowly transmit less frequently than those that are moving faster or are maneuvering. These may have two receivers, for monitoring both frequencies simultaneously, or they may switch between frequencies thereby missing messages on the other channel, but at reduced price. Class B transceivers are smaller, simpler and lower cost than Class A transceivers.

All data are in real time. Coast Guard Navigation Center.

International Secure Systems Lab. International Telecommunications Union.

One of the few messages whose data is entered by hand. The project was proposed and sponsored by the Danish Maritime Safety Administration. Its propagation is better than that of radar, due to the longer wavelength, so it is possible to reach around bends and behind islands if the land masses are not too high.

Navigation menu

Automatic identification system

Applicant Information System