[Laser] Re Laser records and IR experiments.

[Kerry Banke]

A few years ago Lee, KD0IF and I set up a 940 nm tone only beacon for a NLOS propagation study.  The paper was published in the MUD2008 proceedings. The beacon consisted of 200 LEDS running at 100 mw input power each with a 20 deg beamwidth. Just bare LEDS with no lens system. The NLOS path to my home was 7.5 miles. With the moisture and pollution particles in the air, the signal was always 8-20 dB above the noise in a 1 Hz BW. The receiver was a 12" microwave dish covered with reflective Aluminum tape using the K3PGP type detector/preamp circuit. I'll be happy to email the article if requested.  For a number of years we have done NLOS tests using 910 nm Lasers over a 15 mile path using PSK31, Jason and other digital modes. 
73 - Kwerry Banke N6IZW - 

--- On Sat, 4/30/11, Des <d29602960 at yahoo.co.uk> wrote:

From: Des <d29602960 at yahoo.co.uk>
Subject: [Laser] Re Laser records and IR experiments.
To: laser at mailman.qth.net
Date: Saturday, April 30, 2011, 3:26 AM

Hi Stuart (G8CYW) and the group,

First of all, congratulations on your recent success between England/Scotland on a beam of light and on your recent IR tests.

I have been following your experiments with LED comms both on this list and in Rad-Com with some interest.

I note that in many cases you have successfully covered distances with plenty of "reserve" signal to play with. This suggests that communication over much shorter distances (a couple of km perhaps) might be possible using some form of non line-of-sight mode such as atmospheric "scattering" and I wondered if you had done any experiments of this type to date? If so, In any event I would be interested to hear your thoughts on the subject.

Best wishes from a very
 sunny central UK.

Des (M0AYF)
 


http://www.qsl.net/m0ayf/
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