(20 August 2013, 10:58)bigpaul Wrote: anything flashing will be seen, and probably a long way off, could end up with a mob of looters coming to investigate.
That's the point of this idea BP the light is onlt visible in a very restricted area.
Its the same principle as was used for landing glide path to small airports. Long light tubes with Orange Green and Red lights in them. You were on the correct glide path if you couls see Green lights at the end of the runway. If en runway lights appeared red you were too low and had to climb.
I agree that lights have to be ised very carefullt as they will attract attention... as I said at the start, just a crazy idea.
BP If my math is correct, Using a light tube made from 2 meters of 1/2'' plumbing pipe, the beam-width would be around 0.5 degrees, so at 1Km away you'd have to be +/- 15 ft of the beam centre to be able to see the light.
Between two houses 1km apart it is almost certain that the viewing angle can be restricted to just the target house.
Of course lengthening the light tube will reduce the beam-width / viewing angle even further.