FAQ (Frequently Asked Questions)
- What is AIS?
- Do all vessels transmit AIS data?
- What kind of information is transmitted over AIS?
- Why are only some or no ships in my region visible?
- In what form can I get vessel information from Vesseltracker?
- What is Satellite AIS and what is unique about Vesseltracker in this respect?
- What benefits can I receive as a ship photographer, hobbyist or enthusiast?
- How does the photographer list work ?
What is AIS?
AIS stands for Automatic Identification System. It was introduced by the IMO (International Maritime Organization) to improve safety in the maritime traffic. All ships equipped with AIS transponders exchange their current movement data such as position, course and speed as well as other additional information via the VHF channels 87B and 88B. In professional shipping, the system is already part of the equipment requirements for SOLAS (Safety of Life at Sea).
Do all vessels transmit AIS data?
For vessels on international voyages AIS is mandatory from 300 gross registered tonnage (GRT) upwards. For vessels on national voyages it is mandatory from 500 GRT and up.
What kind of information is transmitted over AIS?
Vessel name, call-sign, MMSI number (user ID), IMO number, position (lat/long), course over ground, speed over ground, true heading, rate of turn, length, beam, draught, type of vessel, navigational status, destination and estimated time of arrival and can be separated into 3 different signal types as shown below.
1. Static Information:
- IMO Nummer (if available)
- Dimensions (length, beam, reference points)
- Type of ship
2. Dynamic Information:
- Current Position
- Time in UTC when the position was measured
- Course over ground
- Speed over ground
- true heading
- Navigational Status
- Rate of turn
3. Voyage specific information:
- ETA (estimated time of arrival)
Why are only some or no ships in my region visible?
Our terrestrial AIS network is constantly expanding and may currently not cover all world regions you are looking for. We are however more than happy to work with you in your region to ensure coverage. If you would like to work with us and become an Antenna Partner and cover your region, please contact us. You may receive a system and coverage free of charge for doing so!
In what form can I get vessel information from Vesseltracker?
Vesseltracker provides the most comprehensive and accurate feed of global shipping on the market and offers live data services via API (SOAP and REST), NMEA or FTP as well as customized historical extractions, reports and analytics and standard modules such as vessel movements, port events and ShipDB - characteristics and ownership in a variety of formats. Contact us.
What is Satellite AIS and what is unique about Vesseltracker in this respect?
Satellite AIS (S-AIS) is an emerging technology designed to detect
wide area maritime vessel movements on a global scale. S-AIS extends
the range of the existing maritime Automatic Identification System
where previously, detecting vessels only occurred within a relatively
short range from shore, and thus allows a more complete global
As a satellite orbits the planet it collects data and, transmits that data back down to earth when it is in sight of a compatible ground station. Typically satellites will process this data on-board the satellite and as the processing power is limited to that on-board the satellite itself much data (vessel positions) may be thrown away. This is where Vesseltracker differs from any other provider.
Vesseltracker operates the only satellite constellation that uses a patented technology called spectrum de-collision processing (SDP), also known as on-ground-processing. SDP means we do not throw any information away but rather send it back down to earth so it can be processed further with more advanced algorithms. SDP enables the detection of more than 5 times the number of vessels per pass than non SDP satellites (all other satellites) - see below image.
What benefits can I receive as a ship photographer, hobbyist or enthusiast?
Please register for our Free Account. Then you can upload your photos to our community and comment on them. Once you have uploaded more than 500 photos simply get in contact with us and we will be more than happy to provide you with some extra features free of charge. Click here to register now.
How does our photographer list work?
The photographer list works as follows:
- To have your name shown in the list, you will need to upload 50 photos or more.
- The ranking order is determined by the number of photos, the number of vessels and the number of votes your photos have received from other users. These three parameters also have different influence on the order, i.e. 50 photos of 50 different ships will be rated higher than 50 photos of 10 different ships.
- The photographer list is updated weekly.