Night Vision Goggle Assessment Techniques with Incompatible Cockpit Lighting and a Modified Class B Goggle.

Abstract

Visual acuity (VA) is the standard form of measuring visual performance among pilots in the U. S. Air Force. Yet, during cockpit light evaluations using night vision goggles (NVGs), it has been noted that VA remains constant despite noticeable loss in apparent visual contrast. Therefore, contrast sensitivity (CS) may be a useful measure of visual performance under degraded viewing conditions. The objective of this research was to demonstrate that CS is a viable, additional visual performance tool in NVG cockpit light compatibility evaluations. This study investigated both NVG-aided CS and VA performance with incompatible cockpit lighting. Green and red lights, used in NVG compatible cockpits, were used to accomplish the degradation from a baseline or no-light condition. The lights were placed directly in the NVG field of view (FOV). Twenty subjects were assessed under three light conditions. The subjects viewed three newly developed NVG CS charts and two VA charts. The 3 CS charts had spatial frequencies of 3, 6, and 12 cycles per degree (cpd) and 16 levels of decreasing contrast. The two VA charts were the NVG Resolution chart and the USAF 1951 Tri-bar chart. The type of NVG used contained a new NVG Class B filter, which enables a pilot to view the heads-up display (HUD). The CS charts proved to be an effective tool in evaluating an incompatible cockpit light. The two different VA charts were compared and found to produce the same VA scores in all conditions. The combined assessment procedures of CS and VA provided an accurate visual performance assessment of an NVG under an incompatible light. The modified Class B filter demonstrated that it meets all the cockpit lighting requirements of the military specifications.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1996
Accession Number
ADA318700

Entities

People

  • Randall W. Gibb

Organizations

  • Arizona State University

Tags

Communities of Interest

  • Biomedical
  • Human Systems

DTIC Thesaurus Topics

  • Aircrafts
  • Analysis Of Variance
  • Aviation Accidents
  • Detection
  • Experimental Design
  • Filters
  • Light Sources
  • Literature Surveys
  • Military Medicine
  • Night Vision
  • Optics
  • Psychology
  • Sine Waves
  • Square Waves
  • Standards
  • Test And Evaluation
  • Visible Spectra

Readers

  • Circadian Sleep-Wake Regulation and Chronobiology
  • Human-Computer Interaction (HCI).
  • Vision Science/Vision Psychology/Cognitive Neuroscience.