On Thu, 7 Oct 2004, Dwight K. Elvey wrote:
From:
"Vintage Computer Festival" <vcf(a)siconic.com>
---snip---
There was also a discussion about bouncing
signals off the moon to create
a delay-line memory of sort.
What if we were to preserve software by encoding it as audio and bouncing
it off the moon? I figure we could probably save a few old programs that
way :)
Hi
You'd need a few different frequencies. The round trip to
the moon and back is only 2.6 seconds. It would be much more
reliable if there was a repeater on the moon otherwise the
signal would be weak.
Dwight
You'd need a way to overcome the severe phase-rotation and libration
fading artifacts that make Earth-Moon-Earth reflection-mode communications
a peculiar (and rather frustrating) hobby for us Hams.
Folks use large, high-gain (10 meter > up) dishes, and legal-limit
output powers (1500Watts at 450 MHtz) and specialized communication
algorithms, like phase-coherent Morse Code, in order to actually send
'intelligence' - even using a keyed unmodulated carier, the throughput is
byte-per-minutes.
Have to use a whole lotta wait-states for the EME buffer...
Cheers
John