I love AIS for traffic management. When I first was going through the
English Channel in 2000, our radars were interfaced with GPS, so when we called
another ship we read off their course and heading, as well as their
location. We then told them that we were the ship so many miles and at
some bearing to them. This was reasonably accurate, but a lengthy
process. Today with AIS, especially if they are interfaced with the radars
(mine aren't unfortunately), you can call a ship by name and/or callsign and
they can find you by name or callsign. It makes for much clearer
communications.
In addition to the name data, the AIS also computes a GPS-based set
of CPA to augment the radar computed CPA. The AIS also responds
much quicker than the radar to changes in course and speed so gives a
much quicker updated CPA after a course/speed change than does the radar.
Also, with an effective range of about 30-50 nm, you can tell a ship is a
approaching well before the radar pip appears.
I hope that many small vessels spend the money on AIS. I think that
they should be able to rig an AIS to sound an alarm, for the sleeping solo
sailor especially, indicating an approaching vessel and also warning that
ship of their presence given the often poor radar returns of fiberglass
boats. I am confident that it would make the oceans a bit safer for
all.
On the negative side of the coin, AIS signals all of that information to
anyone with a receiver, including those persons wishing to do harm. AIS is
discouraged in the waters off Somalia because it pinpoints the position of
possible victims to pirates in the area.
Jeremy
In a message dated 2/22/2010 8:38:58 A.M. Eastern Standard Time,
carlzog@gmail.com writes:
Marinetraffic.com is one of several such sites. Others include:
vesseltracker.com, aislive.com and shipais.com.
Although to the casual observer it may serve as little more than a
time-killing curiosity, these sites are marketing their data to shipping
interests who are eager for live data. (Most shipping companies already have
other sources of live data on their own ships.) For example, a blog on
marketing for the shipping industry just posted on the value of these sites to
sales efforts:
http://5956n.typepad.com/59_56_n/2010/02/marine-traffic-hogs-shiptracking-sites-are-booming.html
Additionally, I imagine these data streams are already in use by government
policy makers on a wide variety of fronts.
Carl Herzog
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