AIS monitor software - outstanding for hams & other technical types

[Randy and Mary Davison]

Now here's a neat piece of software I've been playing with for a week or so.  As of late 2004 all ships over 300 tons have to carry AIS (Automatic Information System) transponders.  These send a complete description of the ships actions and status including location, speed, type (tug, ferry, tanker etc.), name, ident number and so  on.  There's a software package that grabs this info off marine channels 87 or 88 and plots it on imported charts or satellite pictures.  See http://www.shipplotter.com for complete info and software download.  It's free for 21 days and then 25 Euros for individuals.

This data is sent every few seconds on both channels so you only need to listen to one of the channels to see all the ships.  When the program knows a ship location, it enables you to download a satellite picture of the area from the internet.  The picture is already scaled and just shows up as the background for the ship plots.  In fact, you can select from among a number of different sat pics incoluding some shot the day before!  It also imports BSB format charts that you can download free from http://nauticalcharts.noaa.gov/mcd/Raster/Index.htm.  These are also autoscaled and require none of the usual screwing around to get them running in the program.

Shipplotter also draws a line in front of each ship showing where it will be in ten minutes and a track showing where it's been.  Ships can be color coded by type.  I've set ferries to be red, tugs to be yellow, tankers to be orange etc.   There's also a radar format display.  Both it and the chart/sat display autocenter on standard NMEA GPS input.

There is a rub.  The program needs to get its data signal directly from the discriminator output of the receiver.  This requires running a shielded wire from the discriminator of the receiver to a new jack.  See the link on the web site for how to mod most of the common scanners available.  I've modded a Radio Shack Pro-2006 and a Bearcat 245XLS.  Both work fine.  The signal from the reciever runs into your soundcard input (mono).  The instructions in the program show how to set it up.  The web site says the software will also work with commercial products that output the data in digital form but I didn't look into that as I had scanners around to use.

Scanners that will work can be picked up on e-bay for a song.  See the mod page left edge for ones that will work.  I can vouch for the ones above but not the rest.

I'm going to run this software on my navigation laptop on Gorbash as standard practice even though I have radar.  It won't solve the small boat problem but there won't be any of the unhappy surprises with big, fast ships that happen at Turn Point or through Active Pass in BC here in northwest waters.

You can listen to the data on channels 87 and 88 but won't hear much.  The data bursts are only 1/30th of a second long and sound like very short noise bursts.  I'm not sure I'd have noticed them by casual listening.

Hope you find this interesting and/or useful.  It's a very slick piece of software.  I have no association with these folks in any way - just an addiction to trying new ham and marine software packages. 

[Stu Jackson]

Great input, thanks, Randy.

Max Ebb's article in the April 2006 issue of Latitude 38 discusses AIS.

[Randy and Mary Davison]

I'll look at it Stu.  I imagine commercial products will show up soon as it makes a great "poor man's radar" for big ships and tugs with tows.  It doesn't take much of a receiver to do the trick.  Ideally, marine radio manufacturers would put an AIS output jack on standard radios.

[David Sanner]

That's what I've been thinking Randy.

Since a VHF radio is connected to a VHF antenna (which is what AIS is transmitted on)
it seems like a logical combination.   If a class D VHF radio can listen on DSC Channel 70 while it
transmits on another channel so I don't see why it couldn't also listen to to the AIS channels.
And if this works that's not only one less box but it's one less antenna and other
cabling or NMEA multiplexing.

All you need to do is send your VHF radio GPS position information
(needed for DSC functions) and it could outputs all DSC and AIS data
back to your plotter or any other hardware.