The effects of field of view size on the control of roll motion

Human operator characteristics were measured during a fixed-base visual tracking task where the field of view (FOV) varied from 10° to 120°. Using the critical tracking (CT) task, five subjects were tested at 10°, 20°, 40°, 80°, and 120° FOV. The measured effective time delay declined exponentially as the FOV increased. The corresponding root-mean-squared (RMS) error followed a U-shaped curve with the majority of the RMS reduction at 40° FOV. A second experiment, in which two subjects were tested at 10°, 40°, and 120° FOV, used a time-invariant plant to allow the measurement of human describing-function parameters. The crossover frequency, increased at least 5% and the RMS error dropped by at least 20% at a FOV of 40° or 120° compared to 10°. The results from these two experiments show that a FOV as small as 40° can produce performance improvements of the same magnitude as a FOV as large as 120°. In the final experiment, where only the central 10° of the scene rotated, performance was unexpectedly best at 10° and poorest at 40° and 80°