THE EFFECTIVENESS OF A COLLIMATED RETICLE AS AN AID TO VISUAL DETECTION OF AIR CRAFT AT HIGH ALTITUDE

摘要

Pilots and observers in planes at high altitudes have reported difficulties in visual detection of other aircraft. The purpose of the present tests is to determine if a collimated reticle aids in detection by correcting for the near-sightedness which maybe induced by an empty field.n The method simulated search for other aircraft against a bright uniform background. Fourteen subjects, using binocular vision, identified the position of a target dot seen at optical in­finity. The cues for near vision were such as a plane's cockpit and the windshield framework might provide. The target dot was systematically varied in size and in position within the otherwise uniform illuminated field. Under these conditions, the minimal size of target for detection was measured when no reticle pattern was present and when each of three representative reticles was seen at optical infinity.