[amsat-bb] Re: Automatic doppler tracking of DSB

laura halliday marsgal42 at hotmail.com
Mon Feb 11 13:49:31 PST 2008

James N5GUI wrote:

> I am curious what got you to thinking about Doppler frequency tracking
> on the BPSK signals.  Did you consider a specific approach on how? Had it
> occurred to you that it might have application beyond BPSK or AO-16?

I was thinking of a particular application, and a particular
way of solving a particular problem. In particular (!), I was
thinking of how I might make a very simple, generally idiot-
proof way of receiving AO-16. No megabucks on a 736 and
a computer, which is how I was doing it at school. The
signal is BPSK. Use it, rather than the clunky open-loop
tracking AMSAT usually uses. BPSK has a certain elegance,
and I wanted a more elegant solution.

Of course such things have wider applications. I'm not
completely stupid...

Along with this was the notion of a phased array antenna
that would place its main lobe at the optimal angle for
receiving satellites. The amount of time the satellites
spend directly overhead is small, while signal levels at
the horizon are low. Optimum is somewhere in between.

Laura Halliday VE7LDH      Que les nuages soient notre
Grid: CN89mg                           pied a terre...
ICBM: 49 16.05 N 122 56.92 W     - Hospital/Shafte

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