I for one, think this is a super-cool project.

I've been waiting for the ham radio types to come in, who know more about
the radio side, and especially what is legal.  For that kind of range, you
need either a short-wave radio that will skip, or a transmitter that can
talk to a satellite.

For the short-wave approach, the ham guys might know how you can legally
have a remote-operated transmitter off in international waters operating on
a short-wave ham band.  If you put it up using a standard modulation scheme
and publish its frequency and transmission schedule, you can probably get a
lot of help in receiving the reports, with receivers scattered about both
sides of the ocean.

It will take a few watts to push a signal across the ocean, but the message
need only be a few milliseconds long.  50 bytes at 1200 baud is 417
milliseconds.  You should be able to use less than 50 bytes, and possibly a
higher bit rate as well.  I would run the transmitter from a bank of low-esr
capacitors that were charged up from whatever power supply you're using for
motors, etc.  If it transmits, say, every 4 hours, and has a 50% probability
of being received each time, then you will get an average of three position
reports per day.  The probability of getting them all goes way up if you
have 10 receivers at different positions.

> -----Original Message-----
> From: Tobie Horswill [mailto:thorswil@EXMACHINA.QC.CA]
> Sent: Thursday, October 19, 2000 1:15 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [OT]: Long range position feedback anyone ?
>
>
> Hi Roman,
>
>     Well actualy, the boat is still in the making ... I'm
> building it just
> because I like the idea of a totally closed and autonomous
> system, I don't
> have the money to travel and the "hi-tech message in a bottle" idea is
> something I've been thinking of for some time. The boat should start
> somewhere off the Canadian east cost and head for France,
> Spain or Portugal
> and then come back. It'll be saving daily position logs to
> EEPROM so I can
> plot it's course but still, I'd like to have a real-time
> position feedback
> if possible ... And no, I don't do this often, this is the
> first time. :-)
>
> Regards,
>
> Tobie Horswill
> thorswil@hotmail.com
>
>
> ----- Original Message -----
> From: "Roman Black" <fastvid@EZY.NET.AU>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Thursday, October 19, 2000 1:53 PM
> Subject: Re: [OT]: Long range position feedback anyone ?
>
>
> > Hi Tobie,
> >
> >         I'm fascinated, why do you have a little boat roaming around
> > the middle of the atlantic ocean? Do you do this often? :o)
> > -Roman
> >
>
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