What is your power budget on the boat (ie: watt-hours per day or some such
units of measure).

Bob Ammerman
RAm Systems
(contract development of high performance, high function, low-level
software)

----- Original Message -----
From: Don Hyde <DonH@AXONN.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, October 19, 2000 3:41 PM
Subject: Re: [OT]: Long range position feedback anyone ?


> 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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> >
>
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