AIS principle, SOLAS requirements, AIS function, advantage

AIS principle, SOLAS requirements, AIS function, advantage

AIS principle
Consists of one VHF transmitter, two VHF TDMA receiver, one VHF DSC receiver, display unit and sensor system.
Automatic exchange of static, dynamic and voyage related data between ship to ship or ship to shore.
Vessel name, call sign, position, time, speed, navigation status, safety information.
GPS give position and time to AIS.
Various bridge equipment give various information through sensor system.
Vessel name and call sign is programmed when installing AIS.
AIS works continuously at open sea or coastal water or inland areas.

AIS requirements
All ships 300 gt and above, international voyage
Cargo ships 500 gt and above, not international voyage
Passenger ship of all sizes

AIS function / AIS advantage
Automatic exchange of static, dynamic and voyage related data between ship to ship or ship to shore.
Vessel name, call sign, position, time, speed, navigation status, safety information.
Basic function is to improve safety and security.
Collision avoidance: Improve situational awareness and safety of navigation.
Vessel traffic service: Busy water traffic movement.
Maritime security: suspicious activity within EEZ.
Search and rescue: AIS SART
Aid to navigation: Recon and marker.
Accident investigation: Connection with VDR
Radar information: give target information, find target behind blind area

AIS disadvantage
Received information depends on the transmitted information.
Position received might not be WGS 84 datum.
AIS information can be wrong.
Some ship doesn’t have AIS.
Some ship might switched off AIS, so avoid over reliance.