Evaluation of display legibility through luminance mapping: An application to aircraft cockpits

This work focuses on the assessment of displays legibility within an aircraft cockpit in presence of typical external lighting condition occurring during flights: these range from clear sky with sun in different critical positions, to cloudy and nightlight sky. Existing procedures to assess the display legibility proposed in literature were analyzed and an operative methodology, based on both objective measurements and subjective evaluations, was proposed. The application of the methodology is intended to be supported by the use of the Sky Light Simulator (SLS), an innovative ambient lighting facility capable to reproduce the sun and the sky dome, hence generating lighting environments closely matching the real ambient lighting conditions, and to host real aircrafts. The paper presents the state-of-the-art relative to existing standardized procedure for assessing display legibility, the operative procedure which is proposed, based on the use of an Imaging Luminance Measurement Device (ILMD), and the results of a first series of the on-going experimental field measurements.