[linux-elitists] Must have free space lasers!
Fri May 4 07:28:16 PDT 2001
OK I feel like I should step in here. Ben puts on his HAM hat.
> >>>>> "EL" == Eugene Leitl <Eugene.Leitl@lrz.uni-muenchen.de> writes:
> >> Anyone tried free space lasers yet? And does the
> >> lightpointe.com web
> EL> You mean line of sight (LoS) lasers? I've seen a 119 kBps DIY
> EL> laser modem from some folks in Oz, but anything else looks
> EL> really expensive, like.
> Damn, I thought this was about, like, satellite-mounted laser weapons
> I could use for free (kinda like the zPenguin thingy, but way more
If you want to do communication that is not line of site you should
use lower frequencies rather than higher frequencies like visable
light. The absorbtion of higher frequencies is quite noticable. That
is why you really can't see that far. However, radio goes through
buildings and finally short wave radio bounces all around the world.
> I'm trying to think of how you'd do laser communication that -wasn't-
> line-of-sight. I mean, unless you don't count mirrors as
> line-of-sight. Can you do atmospheric bounce with lasers? Masers?
> I guess if you had a powerful enough laser, eventually anything that
> was blocking your line of sight would open up and you'd have a nice
> clear path.
You can use extremly low power if you use spread spectrum.
> ~Mr. Bad
> Mr. Bad <firstname.lastname@example.org> | Pigdog Journal | http://pigdog.org/
> "Statements like this give the impression that this article was
> written by a madman in a drug induced rage" -- Ben Franklin
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