The Performance Of Ground Observers In Detecting Recognizing And Estimating Range To Low Altitude Aircraft PDF Download

Detection tests with low-flying jet aircraft were conducted to determine the effect of (a) varying the location of observers from the flight path, (b) using optical aids vs. unaided observation, and (c) varying the amount of temporal early warning. Also tested were man's ability to (a) visually estimate the distance to high-speed jets, (b) track aircraft by ear, and (c) determine the distances at which various aircraft structural features were recognized. When distant terrain masking existed, unaided and optically aided detections occurred at approximately the same time. However, when near terrain masking existed, unaided detections occurred sooner. Using binoculars resulted in earlier recognition of structural features. A change from one minute to five minutes of temporal early warning did not affect detection range. As offset increased from 200 meters to 3,300 meters, detection range increased. The range estimation tests were inconclusive. The results of the auditory tracking tests suggest that it may be possible to extend the capabilities of some fair weather air defense systems to poor visibility conditions. The order in which structural features were recognized was different between fighters and bombers, but there were consistencies within each class of aircraft.