[Laser] Re: Laser "guide star"

Fri, 5 Mar 2004 11:28:17 -0800 (PST)

here is some more info about this type of laser:
http://www.llnl.gov/urp/science/lgs_www/lgs_lick.html
http://www.t4.lanl.gov/pwm/adaptive.html
http://www.gemini.edu/documentation/webdocs/spe/spe-ao-g0094.pdf

>From what i've read, it looks like the San Jose laser
is pulsed at an 11 khz rate with a pulse width of 100
ns. The signal at 11 khz would be easy enough to hear
but the very narrow pulse width may be a problem. I
think a 100 ns period corresponds to a frequency of 10
mhz. So it may be necessary to have a 10 mhz or wider
bandwidth on your receiver with some pulse stretching
circuitry in order to hear it. The light pulse from
the sodium layer "star" may have a longer pulse width
than the laser itself, depending on how long it emits
light after being "zapped".

> 
> Message: 1
> From: "Brian Butler" <[email protected]>
> To: <[email protected]>
> Date: Mon, 1 Mar 2004 11:35:49 -0800
> Subject: [Laser] Laser "guide star"
> Reply-To: [email protected]
> 
> Folks:
> 
> Thanks for the mail reflector, it helps us that are
> new to Laser Comms get
> started.
> I am hoping the clear air and low winter temps (-40)
> north of the 60th
> parallel will
> get me farther with cloudbouce.
> 
> I noticed an article at Spaceflight Now -
> 
> http://www.spaceflightnow.com/news/n0402/29optics/
> 
> This is a 60 mile VISIBLE (sodium line: 589 nm)
> beam!
> Has anyone in or near San Jose seen this beam?
> Can we use it as a beacon or target for our amateur
> cloudbouce comms?
> Can we use it to "calibrate" our systems ... using
> the reflections from it
> to confirm our low-power system's reflections?
> Any other ideas?
> 
> VY1BB
> Brian Butler
> Whitehorse, Yukon
> Canada
> 
> 
> --__--__--

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

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