Pilot performance as a function of display resolution and field of view in a simulated terrain following flight task using a synthetic vision system

The implementation of Synthetic Vision Systems (SVS) has posed a number of design questions. One of these questions is centered on the minimum required display resolution of the synthetic vision display. Although a very high resolution display may be desirable from a product appeal point of view or for increased image fidelity, high quality displays may be prohibitively expensive, particularly for general aviation pilots. Also, there may be a marginal rate of return in terms of pilot performance, workload and situation awareness (SA). A second important issue is the field of view used in displaying the synthetic terrain. Smaller fields of view are more conformal with the natural view but appear to offer a smaller amount of navigationally relevant information than do wider fields of view. A large field of view offers the pilot more information, but distorts the image similar to what happens when wide angle lenses are used on cameras. Further, the optimal field of view may differ based on the phase of flight. The Operator Performance Laboratory (OPL) at the University of Iowa conducted an experiment to assess human performance as a function of display resolution and field of view. Licensed instrument pilots flew sixteen approaches in the OPL General Aviation Workstation II (GAWS TOO) flight simulator with varying display options to determine the effect of the displays on flight technical performance. Performance was measured for four display resolutions, ranging from 120 pixels per inch (best) to 80 pixels per inch (worst). Field of view ranged from 22° (conformal) to 90° (greatest minification). Flight technical performance of the pilots was measured using four objective measures: cross track error, lateral track error, runway alignment deviation, and control input. The first three measures provide a re