EVALUATION OF NAVIGATIONAL RANGE LIGHTING PARAMETERS FOR DAYTIME AND NIGHTTIME CONDITIONS
The purpose of this study was to evaluate, using experimental methods under actual field conditions, parameters and relationships used by the U.S. Coast Guard (USCG) in the design of daytime and nighttime lighted parallax navigational ranges. In one experiment, thresholds of minimal separability, in terms of the angle at the observer's eye subtended by two lights, were measured for various light intensity combinations under both daytime and nighttime conditions. In a separate experiment, thresholds for detection of lights under daytime conditions were determined. Results suggest that the current process used by the USCG to prevent blurring together of the two lights while minimizing required tower heights for nighttime ranges is valid. For the daytime results, the design guidelines for minimum tower height separations, for the illuminance levels evaluated, are adequate for illuminance ratios less than 1.6:1. Results for the second experiment showed that the present USCG practice of using a factor of 1000 to convert the illuminance level specified for nighttime range light signals to a level adequate for daytime use is also valid. This Validation of current practices allows the USCG continued significant cost savings in the construction of towers used for navigational ranges.
- Record URL:
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Corporate Authors:
United States Coast Guard
2100 Second Street, SW
Washington, DC United States 20593 -
Authors:
- Lakar, K V
- Amerison, T L
- Wagner, S L
- Fitzpatrick, M
- Timpe, G L
- Publication Date: 1998
Language
- English
Media Info
- Features: Appendices; Figures; References; Tables;
- Pagination: 37 p.
Subject/Index Terms
- TRT Terms: Construction; Daylight; Eye; Field studies; Light; Lighting equipment; Navigation lights; Night; Separators; Signal lights; Towers; Validation
- Identifier Terms: United States Coast Guard
- Subject Areas: Construction; Marine Transportation; Operations and Traffic Management;
Filing Info
- Accession Number: 00972720
- Record Type: Publication
- Report/Paper Numbers: CGR-DC-17-98
- Contract Numbers: DTCG39-97-X-E00020
- Files: NTL, TRIS
- Created Date: Apr 8 2004 12:00AM