Visual-motion cueing in the control of altitude

The vertical motion simulator at the NASA Ames Research Center was used to examine how platform motion and visual level-of-detail (LOD) cueing affected altitude repositioning and vertical rate control in two tasks utilizing a simulated AH-64 Apache helicopter. The LOD manipulation caused optical density to change across altitudes by a small, moderate, or large amount. The platform motion manipulation resulted in platform motion being either present, and 1:1 (full), or totally absent. Both small optical density changes and platform motion improved altitude judgements in the altitude repositioning task, while platform motion improved performance in a vertical rate control task. These findings show that: 1) vertical platform motion mitigates the tendency of pilots to mistake optical flow rate (angular visual speed) as proportional to vehicle speed during altitude change, and contributes to the perception of movement amplitude; and 2) maintaining nearly constant optical density across altitudes improves altitude judgements.