[OZAPRS] VHF Propagation and Prediction

[Alex Taverner]

Hi Paul,

AIS is similar in many ways to APRS (timesliced packetised data
transmission with corrdinate & status information), but there are some
fairly significant differences due to the requirement to allow
integration with GMDSS systems and use of DSC.

Wikipedia has a good entry on it
(http://en.wikipedia.org/wiki/Automatic_Identification_System). Have a
look at the 'How AIS works' section which explains it quite well.

You can buy some small AIS systems for yachts and recreational craft
that use a standard marine DSC radio and there are some pretty cool
little USB based decoders available for a few hundred dollars that allow
you to see all the traffic. (One of the Sydney based hams watches all
the traffic round the harbour and publishes it on the web this way, I
think).

>From the perspective of sailing yachts, AIS is gold as it makes a small
fibreglass sailing yacht as 'big' as a bulk carrier to the commercial
traffic that normally doesn't see yachts on their radar systems.

73,

Alex VK2RZ

On Thu, 2010-02-25 at 10:50 +1030, Paul Mullins wrote:
> I was wondering if any body up here knows how the VHF marine one works, 
> is it the same as the HAM APRS? I know its a silly question but, this is 
> the reason why I ask two weeks ago my parents went out boating the craft 
> is fitted with some of the latest NAVMAN radio, gps and depth sounding 
> equipment all of which is interconnected, the radio can send GPS info, 
> if it is using the same it would be easy for my to know if they have 
> returned, last time they did not phone and I was preoccupied with other 
>   stuff going on was not until 8 pm that I knew the time. If the systems 
> are the same I could track them easy!
> 
> I might look up on the navman site or the marine radio and read the 
> manual but this will be later on.
> 
> I love tools that allow the info gathered to be made more readable.
> 
> Cheers All
> 
> Paul
> 
> Steve Page wrote:
> > No worries Paul, just trying to spread some good ideas. By the way, 
> > farthest ship logged was actually yesterday at 1,313 Nautical Miles from 
> > the (VHF) AIS receiving station. I think that's around 2400 Kms.
> > 
> > 73's
> > Steve - VK6HV
> > 
> > 
> > 
> > Paul Mullins wrote:
> >> Thats an excellent site and I am going to show it to others in the local 
> >> ham group, Many thanks for allowing other to find this tool.
> >>
> >> Cheers Paul
> >> _______________________________________________
> >> OZAPRS mailing list
> >> OZAPRS at aprs.net.au
> >> http://lists.aprs.net.au/mailman/listinfo/ozaprs
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> > _______________________________________________
> > OZAPRS mailing list
> > OZAPRS at aprs.net.au
> > http://lists.aprs.net.au/mailman/listinfo/ozaprs
> > 
>