The system is based on the collection and processing of data transmitted via the AIS (Automatic Identification System). The AIS-Receiving stations that comprise the MarineTraffic network pick-up such data and share it with the MarineTraffic central database.
All vessels equipped with an AIS transponder emit AIS-data which can be received by any AIS-receiving unit provided it is within range. AIS message packets are encoded in NMEA sentences (64-bit plain text). A sample is shown below:
The contents of any incoming NMEA sentence can be decoded. This way, information on the following three basic sections can be deducted:
- Dynamic Information, such as the subject vessel’s position, speed, current status, course and rate of turn.
- Static Information, such as the subject vessel’s name, IMO number, MMSI number, dimensions.
- Voyage-specific Information, such as the subject vessel's destination, ETA and draught.
The central database constantly receives and processes large amounts of AIS-data and stores the most important part of it (together with geographic information on a multitude of ports and areas, vessels' photos and other details). Current positions and/or tracks of vessels are displayed on the MarineTraffic Live Map while Positions History, Vessel Details, Port Conditions and Statistics can be easily found using our dedicated web pages.