JUNGLE VISION. II: EFFECTS OF DISTANCE, HORIZONTAL PLACEMENT, AND SITE ON PERSONNEL DETECTION IN AN EVERGREEN RAINFOREST
Abstract
To furnish control data for future tests of visual performance aids in the Canal Zone, detection thresholds for uniformed human targets were established in the evergreen tropical forest during the rainiest part of the wet season. Thirty artillery observers, with normal vision, were presented 40 randomly appearing targets in a 180-degree field of search at three different sites. Overall detection thresholds (point of 50% detectability) averaged approximately 70 feet, with no significant differences among the sites. One hundred feet was the near-limit of target detectability. The palms and other plants with large leaves in the undergrowth and the extremely low levels of illumination caused by the forest canopy were the greatest deterrents to target detection. Horizontal target placement, individual differences among observers, past experience, and immediate practice had little or no effect on target detectability within the ranges investigated. A comparison of the results of this study and a previous one conducted in a semideciduous tropical forest is included.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- AD0459488
Entities
People
- D. A. Dobbins
- M. Gast