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

Abstract : An observer in motion often experiences motion-produced blur patterns when the relative angular velocities of the visual environment become appreciable. These blur patterns vary in form according to the type of motion producing them and thus are potentially important sources of visual orientation information. Unless an observer is looking straight to the side of his moving craft or perpendicularly to the path of a moving surface, typically the individual blur lines making up the pattern diverge or converge on his retina. Thus if the plane of motion changes, the divergence changes also and the divergence change becomes an important cue for orientation bearing information on motion parameters such as altitude change. This experiment measured human thresholds for divergence change in the form of sinusoidal expansion and contraction of downward-moving 16-line element patterns on the face of an oscilloscope. The objective was to determine whether blur pattern divergence change sensitivity was acute enough to be of any practical value in visual orientation using display information.