5 March 2012 18:10
Each vessel fitted with an AIS transponder transmits its identity, position, course, speed and other information over a VHF channel. This is compulsory for vessels over 300 tons and all passenger ships. Quite a lot of other vessels carry them as well.
So if your boat has an AIS receiver on board you can track these vessels if they are in range, typically 20 miles or so. If the receiver has a display at all it is usually a bit rude and crude – the real trick is to feed the AIS information into your chart display system. Now you can see the AIS targets overlaid onto your navigational chart and this starts to get useful.
AIS was intended and designed as a collision avoidance mechanism however you really need a graphical chart based display to properly realize this. Nuno™ now supports AIS (hooray!) and makes a great way to display the information.
Even on a smaller boat there is a lot to be said for getting an AIS receiver. They are pretty cheap these days and benefit in terms of situational awareness is brilliant.
Configuring AIS in Nuno™ is pretty easy. You need an AIS unit with a NMEA output and then you just plug it in. That’s it. Depending on your set up the AIS NMEA stream may be multiplexed onto your GPS feed or it may be a separate connection. Either way just plug it in and Nuno™ will find it.
AIS targets are displayed as little green symbols with a vector arrow representing speed and direction. Ticks on the arrow are at one minute intervals. Hover the cursor over the target to see additional information such as name, destination and cargo. The scope of the information being broadcast can vary quite a lot.
Here is a really handy technique: Create a pencil line and drop one end onto the marker for your boat and the other onto an AIS target. The line will display range and bearing to the AIS target. Even better the line will ‘snap’ to your vessel and the AIS target and update as they move. Very useful for keeping an eye on another ship.
Nuno™ with AIS capability is being released soon. Very soon. Maybe even today. This is available as a free upgrade to all users with a current license. There are lots of other improvements in this release and some great new features just around the corner.
How do you get it? Easy. Run Nuno™ up on a PC with an internet connection. If an upgrade is available it will tell you in the Support Centre pane and there will be a download link for you to follow.