Underwater display visibility as influenced by turbidity, viewing distance, and color of illumination

Abstract

The purpose of the study was to determine the effects of illumination color, viewing distance, and turbidity on a visual reading task in a totally dark, flooded environment. The reading task was to read a voltmeter and make a correct oral report of the reading. A total of 180 data points spread over 18 viewing conditions were taken for each subject. Seventeen military officers were used as subjects. Experimental conditions were presented in a random manner to all subjects. As statistical examination of the results showed that white or green illumination is better than red in reducing reading response time. Turbidity levels were significant in affecting response time showing an increased response time as the attenuation coefficient increased. There was no difference in the effect of an eight inch viewing distance versus a thirteen inch viewing distance. The error rate was constant, with no variable having a greater effect on the error rate than did other variables. The expected error rate over all variable was .037 errors per each trial taken