Egocentric and Exocentric Displays for Terminal Area Navigation

Abstract

Two experiments are reported that contrast egocentric vs. exocentric features of perspective (3D) or plan view (2D) electronic map displays for supporting local guidance and global awareness. Pilots used these displays for a simulated approach to a landing along a curved approach, through a terrain-filled region. The task was simulated on an IRIS visual graphics workstation. In Experiment 1, a rotating vs. fixed-map display was experimentally crossed with a 2D vs. 3D (perspective map) view as 24 pilots were assessed in their ability to maintain the flight path (local guidance) and demonstrate global awareness of surrounding terrain features. Rotating displays supported better flight path guidance in both the lateral and vertical axes, and did not substantially harm performance on the task of recalling the location of terrain features. Map rotation also supported better performance in locating features from an ego-referenced but not a world-referenced perspective. 3D displays provided a slight advantage for lateral guidance but a substantial cost for vertical control, because of the ambiguity with which perspective viewing depicted precise altitude. In Experiment 2, 10 pilots flew with the rotating 2D display, and with an improved version of the rotating 3D display, using color coding to reduce the ambiguity of altitude information. Vertical control improved as a result of the 3D display design improvement, but lateral control did not. Assessment of terrain awareness on a map reconstruction task revealed marginally better performance with the 2D map. The results are discussed in terms of the costs and benefits of presenting information in 3D, ego-referenced format for both local guidance and global awareness tasks.