ABSTRACT
In the Navy, more than the Army or Air Force, simulator facilities have become adventitious laboratory for the study of simulator sickness. One reason for this is that the Navy, to a greater extent than the other services, tends to have multi-missions (fighter, attack, electronic warfare, search and rescue, etc.) along with rotary and fixed wing aircraft. Navy aviation platforms range from the large P-3C Orion to the light and fast F/A-18 Hornet and all of these now have simulators with wide field of view display systems. Nearly all Air Force simulators are fixed-base systems which simulate centerline thrust, fixed-wing aircraft. U.S. Army systems are largely moving-base platforms simulating rotary-wing aircraft. As a design philosophy, the Army and the Air Force, set out to obtain multiple copies of one type of simulator (U.S. Congress, 1984), while the Navy, as technological advances were made, went through a series of state-of-the-art approaches for different aircraft models. Through this period, the Navy began with pointsource projection systems and since have employed model boards, domes, and multiple CRT systems utilizing computer generated imagery. The latter, which are most in use today, are probably most provocative of simulator sickness. As a consequence, the Navy has taken the lead in terms of problem definition and development of measurement and methodologies to study simulator sickness. Therefore as virtual environments are developed which are also expected to occasion user discomfort, the Navy experience may have the most to teach us about the nature of the problems as well as to identify solutions. Over the past few years various methods have been employed in surveying the incidence of sickness and one of these, spectral analysis of simulator sickness, is featured in this paper.
