5 Jun 2013

Cloudbounce and scatter optical and IR tests

This morning I read a most interesting article about French cloudbounce and scatter optical tests using lasers. The article is some years old but makes a fascinating read. My own experience with clear air forward scatter at optical frequencies using relatively low powered red LEDs makes me believe that a LOT more is possible in this area. It is a bit like people saying, "UHF is only line-of-sight". Rubbish! With decent, easily built kit it is possible to copy QRP amateur signals over the horizon even at IR and visible optical frequencies.

See http://sd-1.archive-host.com/membres/up/22679775843705539/CBVUK.pdf


David Cope said...

Do bear in mind that pointing lasers into the sky which might conflict (accidentally in this case) with (low level) aircraft in flight may bring about a prosecution.

I know this has become a bit of a hot topic in aviation circles due to the increasing number of deliberate targeting of aircraft by laser pointers. The police seem to aggressively pursue reported targeting.

Whilst the red LEDS are not a collimated point source I guess if they are bright enough under the right conditions, they may be mistaken as a laser.

Obviously not a problem with IR.

Just sayin'

73 G8JGO.

Roger G3XBM said...

Thanks David.

Few people use lasers these days, preferring to use high(ish) power LEDs instead. Most in the nanowave community are fully aware of CAA regulations regarding searchlights and lasers near airports and their approaches. IR using high power LEDs is probably the way to go.