On Fri, 13 Sep 2002, Jinx wrote:

>>   "Handbook of Optical Through the Air Handbook"
>>
>> Url:
>>   http://www.imagineeringezine.com/air-bk2.html
>
>"method is shown in figure 7e below. The unit uses 20
>separate LEDs and 20 Fresnel lenses. "
>
>"The system demonstrated a range of six miles when transmitting
>voice audio information
>
>6 miles with LEDs ? Probably tested under ideal conditions
>but that's not bad at all

There are optical data link kits that go to 20 miles line of sight on a 5W
or less ir laser (in almost any weather). These have been around for 15
years or so. There are several companies actively developing such devices.

Peter

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