Visual Cues in Flight Simulation: An Evaluation of Stereo Effectiveness

The purpose of the present study was to quantify the effects of visual scene information on precision hovering tasks under biocular and binocular (stereo) viewing conditions in a rotorcraft helmet-mounted display simulator. Four NASA test pilots performed a series of precision hover maneuvers (hover, bob-up, side step, etc.) in the context of three different scene contents (near several buildings in a village, near a single tree, and in an open field), two ground textures (amorphous ground texture without sharp edges vs. a patterned ground texture with sharp edges) and three levels of control configuration difficulty. The results revealed that vertical position variability was greatest when vertical cues (e.g., buildings, trees) were absent, and that patterned ground texture aided hover stability only when other position-reference cues were absent from the scene. The stereo viewing condition showed no uniform advantages over the biocular condition. The results are discussed in terms of their implications for simulator design and qualification.