ABSTRACT
This chapter discusses the status of research and understanding of the human factors issues of helmet-mounted displays (HMDs). The study of human factors is the study of human characteristics that are applicable to the design of systems and devices of all kinds. The chapter addresses the human factors issues of visual displays. If the design of the display necessitates obscuring a part of the natural field of view, portions the line of sight are considered to be more important to flying performance. The reason for the vibration-induced decrement in performance is relative motion between the line of sight of the eye and the optical axis of the HMD. Vibration is also a factor in the use of helmet-mounted sights and head-coupled systems, where head movement is used to direct weapons, sensors, and other systems. While the conventional definition of resolution is associated with the spatial characteristics of a display, temporal resolution characteristics must be considered when dealing with helmet-mounted displays.
