Estimates of simulated ground relief as an operational test of stereoacuity for aviators


  1. Sudhama, A.
  2. Hartle, B.
  3. Allison, R.
  4. Irving, E.
  5. Wilcox, L.
Corporate Authors
Defence Research and Development Canada, Toronto Research Centre , Toronto ON (CAN);York Univ, North York ONT (CAN)
Stereopsis is not currently a visual requirement for aircrew in the Royal Canadian Air force; however, it has been shown to be relevant to some aviation manoeuvers, particularly aerial refueling and landing. Commercial tests of stereoacuity are widely used to assess stereopsis in clinical practice but may not predict performance in real-world scenarios and tasks. In this series of experiments, we have made the first steps towards development of a stereoscopic depth discrimination task using naturalistic stimuli and a task (terrain relief judgement) that is relevant to flight crew. Stimuli consist of a stereoscopically rendered grassy terrain with a central mound or a dip with varying height/depth. We measured thresholds for discrimination of the direction of the depth offset. For comparison and validation of our Terrain test we also measured observers’ performance on a set of commercial (Randot, StereoFly) and purpose-designed stereoacuity tests: the Ledge test, the Bar test, and the United States Air Force School of Aerospace Medicine (USAFSAM) Operational-based Vision Assessment (OBVA) Ring stereo test as additional comparison tests. To assess the impact of uninformative 2D shading cues on depth judgements in our Terrain test, we manipulated the intensity of the shading (low and high). Our results show that the Terrain test can be used as a test for stereovision, and thresholds are measureable for most observers in the low shading condition. However, as shading is intensi
Human Vision;Aircrew;Stereopsis;Aviation Medicine
Report Number
DRDC-RDDC-2019-C119 — Contract Report
Date of publication
01 Jun 2019
Number of Pages
Electronic Document(PDF)

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