Light Pollution

Here in Columbus, the level of light pollution is severe. Indeed, it is very difficult to see star below the 3rd magnitude. The dark-adapted naked eye is capable of seeing down to the 6th magnitude in localities far from city lights. In terms of seeing where to point the telescope, light pollution does not substantially affect Optical SETI as long as some form of CCD camera or optically-filtered image intensifier is used.

As far as the ability to count photon bursts (beacon pulses), light pollution has little effect. For detection of monochromatic continuous wave beacons, the effect of light pollution is very significant, and the background radiation from the sky and the star itself must be substantially reduced using a narrow-band optical filter or monochromator. This substantially increases the search time since a guess has to be made of the so-called "magic" optical frequencies.