[Laser] moon repeater

Mon, 5 Jan 2004 04:18:16 -0800 (PST)

I was thinking since the delay for the moon signals is
so long, you could just use a mechanical shutter to
block the receiver during a transmit "pulse", then
unblock it for a few seconds to catch all of the
return. In that way eliminating any backscatter. Some
sort of slowly rotating shutter that alternately
blocks the receiver then the transmitter, so you'd be
transmitting for about 2 seconds then receiving for 2
seconds. This along with qrss and averaging ect..

I had thought maybe one could use a buddy about 10 km
away so that they would be just inside the narrow
reflection from the moon. But even at 10km (6.2 miles)
there would still probably be some backscatter from
the upper atmosphere judging from others experiments
at those distances.

Tracking the moon while attempting to get a reflection
is going to be difficult but not impossible of course.
On the other hand, tracking a geosynchronous satellite
will be much easier. Maybe even NO tracking at all
once the beam is pointing right??? At least not for a
few minutes/hours or days possibly.
Satellites in geosynchronous orbit are about 1/10'th
the distance of the moon. The bounced signals could
still cover a very large area (about a 1/3 of the
earth or so). The earth as seen from geo-orbit is
about 17 degrees wide, so the reflector needs a wider
spread to cover most of it. Round trip times for
geo-signals would be about 1/4 second.

>From: "J. Forster" <[email protected]>
>Reply-To: [email protected]
>To: [email protected]
>Subject: Re: [Laser] moon repeater
>Date: Sun, 04 Jan 2004 00:45:59 -0500
>
>Pretty easy test to do though. Clouds will be milli
or micro seconds 
round 
>trip,
>the Moon about 3 seconds and only a very few photons
in amplitude. If 
you 
>get a
>strong return with amateur gear, it's almost
certainly not the Moon.
>
>-John
>
>
>Jim Deane wrote:
>
> > But is there a relatively simple method to
determine whether you 
are
> > receiving moon-bounce signals or atmospheric
scattering from your 
>outgoing
> > beam?
> >
> > Obviously, pulsed signals with an oscilliscope
would be one method 
since 
>we
> > know the rough distance to the moon...but that
seems so kludgy.  
Ideas?
> >
> > Jim
>
--__--__--

=====
Tim
[email protected]
http://www.aladal.net/toast/

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