Saturday, September 4, 2010

AIS Live Tracking

I have mentioned the automatic information system (AIS) before.  A fairly new innovation in shipping AIS consists of a transmitter and receiver that sends digital data via short range (VHF) radio.  Each equipped ship (like Reboot) broadcasts an identification number (Reboot's maritime mobile service identity {MMSI}is 366958630), course, speed, heading, and type of boat.  Class "A" - commercial - ships also broadcast additional information.such as their next destination.  The receiver decodes the digital data and places icons on the chart plotter showing where the other ships are in real time.  This is very handy, particularly when it is raining hard as radar becomes quite useless.

Watching "live" ship tracks has become for some a hobby like watching flight data from airplanes. Clicking on this posts link will take you to Marine Traffic (Live AIS), a site that displays live AIS data from ships all over the world.  I have added a box to my blog so that you can see Reboot in relation to both my current geographic location and other ships in the vicinity.  I will leave it up top for a while and then perhaps move it to the bottom of the blog when I get a new cute picture of XO.

A couple of things to know about AIS:
1.  It is short range.  If I get very far out into the ocean I am going to disappear off the chart.
2.  Not every boat carries AIS.  In particular fishing vessels and tugs don't seem to show up very much.  Military vessels are also frequently missing from the charts.
3.  In some parts of the world -for example Singapore - AIS is required on every vessel.
4.  The network of shore based receivers is like many things internet voluntary.  So coverage is based on who felt like setting up a receive site.  It works kind of like the weather underground.


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