Like planes, it’s mandatory for boats to broadcast their navigation data with a transponder. Ship name, speed, orientation and many other informations are all transmitted regularly with the Automatic Identification System (AIS). AIS messages are easy to decode, allowing everyone to use it. Originally intended for security purposes, AIS data is now widely used to track ships around the world. Moreover, this activity is conducted by companies and amateurs, as ship spotting became the sea equivalent to the train spotting hobby.
Many services aggregate and display AIS data, like MarineTraffic or VesselFinder.While providing elegant interfaces and nice social functionalities such as photo sharing, these websites sell AIS data feeds at prohibitive prices for the regular marine enthusiast.
However, the AISHub project distribute AIS data freely to whoever contribute to the service by sending their own AIS data. The license is pretty clear: do what you want with the data, even sell it, as long as you contribute to the project. Luckily, receiving AIS messages became pretty easy with the rise of RTLSDR. A quick setup using a 20€ usb stick and a fork antenna opens a continuous stream of AIS messages, if ships are nearby of course. Data can then be sent to various services, like MarineTraffic or AISHub.
— Paul Bouchequet (@frenchkpi) 2 juin 2016
Displaying AIS data from AISHub
Then contributors to AISHub have to query the provided API according to their needs. Data is far less complete than paying services. Indeed, the AISHub network of contributors covers less water, and satellite AIS data is not available. However, AIS data is still clean and fully usable. Major ports are covered, allowing tracking of a huge number of cargo ships over the world.
The following dashboard aggregate data from AISHub. Movements over the last hour are display for 3 zones: English Channel, Netherlands coast and Hong Kong. Click on this image to access the dashboard page.
On the first page of the dashboard, position of ships is updated every hour. A green line is traced between the 2 last positions, displaying straights lines over the sea. Only moving ships are displayed. Select a line to open a box showing ship name, type, destination and speed. Other tabs display aggregated information about ships spotted over the last hour by AISHub contributors: ship types, status, destinations…