| From: | Legion is my name-oh! <legion@**************.ARMY.MIL> |
|---|---|
| Subject: | Laser mics (from orbit!) |
| Date: | Sun, 18 Jul 1993 12:04:48 MDT |
to guage the distance to the moon (Alice!) is basically nothing but a
high powered LRF (Laser Range Finder). All it's doing is timing the splash
of the laser. To put it more better (I'm a 'merican too!), the laser is
shot at a point on the moon; the controlling apparatus of the laser times
the amount of time it takes from when the laser fires till "splash" or
laser contact with the moons surface. The amount of time inbetween events
determines the distance.
"What about clouds and other atmospheric conditions?"
Simple. An LRF almost always gets multiple returns; multiple collisions
of the laser and, say, clouds, birds, dust particles and the like. The
final splash, the one that hits the moon, is known to be final for two
reasons; one, they already have an approximate distance to the moon to
use as a reference, and two, the laser isn't going to splash against
anything else after it hit's the moon.
"What about accuracy?"
Easy. Have the laser fire for a minute or three, take readings every
.0001 seconds or so, and you'll have MUCH data to get an accurate
reading by mean calculation.
As for accuracy to the nearest .0000001 inch, or whatever it was,
c'mon, we're not stupid; the moon is NOT a perfect sphere in a perfect
geosynchronous orbit. I think distance closest to the nearest inch would
be more than enough for the eggheads at NASA or whoever uses these
measurements.
_________________________________
Mike Loseke | "You just shot an unarmed man!"
legion@**************.army.mil |
Minister of Death - SWO | "Well, maybe he should've armed himself."
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