Review of colored conformal symbology in head-worn displays

Kurzfassung

The usage of conformal symbology in color head-worn displays (HWDs) opens up a range of new possibilities on modern flight decks. The capability of color augmentation seems especially useful for low flights in degraded visual environments. Helicopter flights in these conditions, including brownout by swirling dust or sand particles, can often lead to spatial disorientation (SD) and result in a significant amount of controlled flight into terrain (CFIT). While first generation color-capable conformal displays are deployed, practical guidelines for the use of color in these see-through interfaces are yet to be established. A literature survey is carried out to analyze available knowledge of color use in conformal displays and to identify established methodologies for human-factors experimentation in this domain. Firstly the key human factors involved in color HWDs are outlined, including hardware design aspects as well as perceptual and attentional aspects. Secondly research on color perception is mapped out, focusing on investigations of luminance contrast requirements, modeling of color space blending and development of color correction solutions. Thirdly application-based research of colored conformal symbology is reviewed, including several simulations and flight experiments. Analysis shows that established luminance contrast requirements need to be validated and that performance effects of colored HWD symbology need more objective measurements. Finally practical recommendations are made for further research. This literature study has thus established a theoretical framework for future experimental efforts in colored conformal symbology. The Institute of Flight Guidance of the German Aerospace Center (DLR) is currently conducting experiments within this framework.