AN INVESTIGATION OF LIGHTING IN DISPLAYS WITH SUPERIMPOSED FIELDS WHILE AT LOW LEVELS OF ILLUMINATION

One type of 'heads-up' display involves the projection, collimation, and reflection of display information from the aircraft windshield in front of the pilot. This type of display may interact with the pilot's visual capability at low levels of illumination. A study was performed to determine which of several alternate lighting configurations resulted in the best dual field performance. Both red and white light were used. The concept of pulsed or intermittent lighting was investigated as well. A three-dimensional factorial experimental design allowed the simultaneous evaluation of the intermittency variables as well as the lighting variable. The task involved performing a continuous compensatory tracking task while simultaneously performing an alphanumeric detection-recognition task on moving elements. Results supported the use of white light. Pulsed white light at a high light-dark ratio and high interruption frequency resulted in performance on a level with that obtained with continuous white light and superior in every instance to that obtained with red light. (Author)