US Navy and Marine Corps Requirements and Challenges: Virtual Environment and Component Technologies

Abstract : The US Navy and Marine Corps have clear requirements for virtual environment (VE) systems and related component technologies for both training and operations. VE systems have been defined broadly to include any computer-based representation of an artificial or real world regardless of the medium of display. A more restricted definition includes only those systems that rely on some form of immersive display where the user experiences and interacts directly with the virtual world as if they were part of the simulation. This paper addresses requirements and technical issues related to the latter category of immersive VIII systems. Discussion will he limited to land, sea and subsurface applications without in-depth treatment of aviation and targeting requirements. Immersive VIII systems are characterized by multiple sensory modalities and direct interaction. VIII displays can include head-mounted visual displays, which are yoked to head position producing the illusion of fully immersive 360- degree immersion. Head-mounted visual displays can be monocular or "see-through" permitting the observer to integrate real surroundings with virtual objects and displays. Another version of visual immersion uses projection displays on a small enclosed space allowing free head movements and natural exploration of the surrounding virtual space. The sense of physical presence created by immersive visual displays may be augmented by spatialized (3-D) audio, which can simulate the acoustic filtering of the head, pinnae and facial features as well as virtual room acoustics. Spatialized audio creates the perception of sound sources well-localized outside the head rather than between the ears as is usually the case with headphone presentation of sound. This expansion of the perceived workspace of the operator takes advantage of the human ability to attend to multiple spatially discrete information sources.