Spatial Orientation from Motion-Produced Blur Patterns: Detection of Curvature Change

When a craft departs from moving straight and level over a flat surface or when the surface is not flat, the motion-produced visual blur patterns that the operator sees change in terms of their curvature. It was demonstrated in a previous experiment that human observers are quite sensitive to blur pattern curvature, the present experiment tested whether observers could respond to blur pattern curvature change at a level of sensitivity that would allow them to detect corresponding changes in path of flight and in terrain height and therefore use these cues for improved orientation. The major finding was that with our electronically generated 16-element synthetic blur pattern display, sensitivity to curvature change was sensitive enough to be quite useful in assessing aspects of one's motion relative to the ground. The performance for the foveal-viewing condition was superior but the peripheral condition also indicated potentially useful sensitivity levels. The results also indicated that slow-moving patterns were more effective bearers of curvature change information as were rapidly oscillating ones.