Accession Number : ADA316971

Title :   Image Update Rate Can Affect the Perceived Speed of Simulated Self-Motion.

Descriptive Note : Final rept. Jun 92-May 95,

Corporate Author : HUGHES TRAINING INC MESA AZ TRAINING OPERATIONS DIV

Personal Author(s) : Lindholm, Julie M. ; Askins, Timothy M. ; Sisson, Norwood

PDF Url : ADA316971

Report Date : JUN 1996

Pagination or Media Count : 49

Abstract : The update rate of an image generator affects the spatiotemporal representation of a time-varying scene and thus, potentially, an observer's percept during observation of the display image. In the first part of this report, we discuss image generation technology and sampling theory, and we present an analysis of the temporal frequencies in a space-time image representing constant-velocity, constant-altitude flight over a flat, textured terrain. In the second part, we report the results of two experiments in which a two-alternative, forced-choice method of constant stimuli was used to investigate the effects of image update rate (30 Hz vs 60 Hz) on the perceived speed of self motion. We found that perceived speed was higher with the lower update rate when the original image, internal to the computer, contained very high temporal frequencies, and the display image, therefore, contained a large number of spatiotemporal frequencies, within the bandpass of the human visual system, which had the wrong drift direction.

Descriptors :   *IMAGE PROCESSING, *VISUAL PERCEPTION, *FLIGHT SIMULATORS, *VISUAL ACUITY, COMPUTERIZED SIMULATION, FOURIER TRANSFORMATION, FLIGHT TRAINING, THREE DIMENSIONAL, COMPUTER GRAPHICS, DATA DISPLAYS, MAN COMPUTER INTERFACE, FLIGHT SIMULATION, IMAGE MOTION COMPENSATION, VIDEO FILTERS.

Subject Categories : Cybernetics
      Human Factors Engineering & Man Machine System

Distribution Statement : APPROVED FOR PUBLIC RELEASE