SITUATION AWARENESS AS A FUNCTION OF FRAME OF REFERENCE, COMPUTER-GRAPHICS EYEPOINT ELEVATION, AND GEOMETRIC FIELD-OF-VIEW

The purpose of this study was to determine how 3 variables for the des ign of a ''heads-down'' spatial display-the frame of reference (pilot' s eye vs. God's eye), geometric field of view, and elevation of the co mputer graphics eyepoint-influenced situation awareness. Thirteen flig ht-naive subjects each flew a simulated F-16 over a computer-generated flight environment to lock onto and intercept a series of sequentiall y appearing targets. The flight scene consisted of both an ''out-the-w indow'' view and a computer-generated heads-down spatial display showi ng an airplane symbol superimposed on a perspective view of the flight environment. During the interactive phase of the experiment, root mea n square flight-path error, target lock-on time, and target acquisitio n time were measured. After the interactive phase of the study was com pleted, subjects were required to mark the location of the targets fro m memory on a computer-generated top-down view of the flight scene in an attempt to reconstruct the spatial mental model which subjects form ed of the flight environment. The results for the interactive phase of the study indicated that performance was superior using the pilot's-e ye display. However, for the spatial reconstruction task, performance was better using the God's-eye display. It was also shown that the abi lity to maintain the optimal flight-path using the more top-down view of the scene (60 degrees eyepoint) was superior to the 30 degrees eyep oint elevation. Implications of the results for the design of spatial instruments are discussed.