Soldiers and vehicles are fitted with infrared laser detectors for
detecting simulated laser bullets and artillery shells from SAT-equipped
small arms weapons and tanks employing laser scanner transmitters. An
infrared LED is mounted inside the protective housing which supports each
laser detector for illuminating the exterior surface of a window, lens or
other transparent optical element positioned in front of the detector.
Dirt, dust, mud, snow, shoe polish or other contaminant on the exterior
surface of the optical element scatters the infrared radiation from the
LED and in accordance with a test periodically performed by a test
circuit, if the scattered signal exceeds a predetermined threshold value,
a visual and/or audible warning is given to the player. If the optical
element is not cleaned within a predetermined time after the warning, a
kill command is executed to prevent the player from cheating.
