What is Automatic Identification System (AIS)
Automatic Identification System is an automatic tracking system this is displays other vessels in the vicinity. The broadcast transponder system operates in the VHF mobile marine band.
Your ship is also visible on the screens of other ships nearby, provided your ship is equipped with AIS. If AIS is not fitted or not operational, information is not exchanged on vessels via AIS.
AIS onboard must be kept on at all times unless the master considers that it should be turned off for safety reasons or for any other reason. The mode of operation of AIS is continuous and autonomous.
Function of automatic identification system
Why is Automatic Identification System (AIS) provided?
what is automatic identification system, It is installed on ships for ship identification and navigation marks. However, this is only an aid to navigation and should not be used to avoid collisions. Vessel Traffic Services (VTS) use AIS to identify, locate and monitor vessels off the coast. The Panama Canal uses AIS to provide information about rain and wind in the locks along the canal.
SOLAS Requirements
All ships of 300 GT and above engaged on international voyages and all passenger ships, regardless of size, are required to carry AIS on board in accordance with the IMO Convention for the Safety of Life at Sea (SOLAS) Regulation V/19.2.4 Is required.
Why is Automatic Identification System (AIS) Types
- Class A: Mandatory for all ships of 300 GT and above on international voyages as well as all passenger ships.
- Class B: Provides limited functionality and is for non-SOLAS vessels. Mainly used for pleasure craft such as vessels
AIS operates two dedicated frequencies or VHF channels:
- AIS 1: 161.975 MHz – operates on channel 87B (simplex, ship-to-ship)
- AIS 2: 162.024 MHz – Channel 87B (duplex for ship to shore communication)
AIS works
How exactly work AIS? How do we get all this data?
Basically, AIS used was terrestrially, that meaning the signal was sent from a boat to land and had a range of about 20 miles (it’s also considering the curvature of the Earth). As the ships began to move away from land, they began sending signals to low-orbiting satellites, relaying information back to the ground. This meant that the ships could go as far as they wanted and we always had peace of mind knowing where they were and how they were doing.
It is also very easy to install, as AIS are usually integrated with ship bridge systems or multifunctional displays, but setting up a standalone system is as simple as plugging in a few cables and switching on the plug.
Data Transmitted
- Static notification every 6 minutes
- Information of Dynamic (course changes and Depends on speed )
- Information of Voyage Related (Every 7 minutes, when data is modified or upon request)
- short safety message
AIS As a surveillance tool
In coastal waters, shore authorities may install automated AIS stations to monitor the movement of vessels through the area.
Coastal stations can use AIS to monitor the movement of dangerous goods and control commercial fishing operations in their waters. AIS can also be used for SAR operations, allowing SAR officers to use Automatic Identification System (AIS) information to assess the availability of other ships in the vicinity of the incident.
AIS as a collision avoidance aid
Automatic Identification System (AIS) makes an important contribution to the safety of navigation. All information transmitted and received increases the effectiveness of navigation and can significantly improve situational awareness And decision-making processes.
As an adjunct to OOW, tracking and monitoring of targets by AIS and determination of information on CPA and TCPA are of great importance for the safety of navigation as a whole.
AIS Limitations
- The accuracy of received AIS information is only as good as the accuracy of transmitted AIS information.
- The position received on the Automatic Identification System (AIS) display may not be referenced to the WGS 84 datum.
- Excessive reliance on AIS may lead to complacency on the part of OOW
- Users should be aware that AIS may broadcast false information from another vessel
- The OOW should be aware that AIS, if fitted, may be turned off by a certain vessel, thereby negating any information received from such a vessel.
- It not be prudent for the OOW to assume that information received from other ships may not be completely accurate and precise as that available on board his ship.
