A Compressed-Scale System of Portable Visibility Lights for Nighttime Use

Abstract

A system of visibility lights for nighttime use at advanced or tactical air bases has been designed by the Visibility Laboratory of the Scripps Institution of Oceanography, La Jolla, Calif. This system enables a more precise estimate of nighttime visibility to be made than has heretofore been attainable by conventional visual observation procedures. Although the system is able to yield visibility estimates to 5 mi or more, it requires less than a. 2-mi path for its installation. The accuracy of the system is achieved by control of the observer's adaption level, as well as by use of a calibrated incandescent (searchlight) source in conjunction with highly efficient retrodirective reflectors. Portability is attained by compact design and packaging and by the use of battery power. The principles and design considerations of the system are also discussed.