For those interested in receiving and mapping ship position reports transmitted using the AIS protocol under the Safety of Life at Sea regulations.

AIS is a system that ships use to communicate their positions to each other as part of the global maritime safety system. From December 2004, all ships over 300 tons must carry an AIS system which broadcasts information about the ship to any suitably equipped receiver. AIS uses very short bursts of high speed data on two VHF channels in the marine band. The two frequencies used are 161.975 (Marine ch 87) and 162.025 (ch 88) MHz. Ships broadcast their identity, position, course, speed and destination so that other ships can take account of their movements. Using a low cost radio scanner tuned to one or other of these channels and ShipPlotter software running on your PC, you will be able to see a radar-like real-time map (below) of all the large ships manoeuvring in your area together with information about their destination, estimated time of arrival and even the dimensions of each vessel.

The display above is updated every few minutes from data received on 162.025MHz by my own station, and by 'sharing' data received by other local stations via the internet. The chart provides a constantly updated record of shipping movements in the Thames Estuary. Furthermore, the 'radar like' plot continues uninterrupted in adverse weather conditions such as sea mist and fog through which visibility is severely restricted. Having said that THIS INFORMATION SHOULD NOT BE RELIED ON FOR NAVIGATION PURPOSES but does allow LAND based observers to keep up with local shipping movements. An advantage of being able to drive the software from an internet data-stream enables interested  participants to watch the action from an inland location. Satellite maps of an area of interest can also be downloaded using the software. A number of examples are displayed here on my website.

Although the display shown above provides detail of ship location, speed, direction and name, a left mouse click on any ship icon on the screen of a PC running Ship Plotter software, reveals a wealth of additional information about the ship, ship type, destination, cargo type and so forth.

For Plane Plotter devotees there is another similar software package, Plane Plotter, available from the same stable, which uses the same or similar scanning receiver, or air-band receiver, to provide the necessary ACARS data stream to display the position, call-sign and speed of commercial aircraft flying within the reception range of the radio.



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