Alternatives to Pyrotechnic Distress Signals; Laboratory and Field Studies
COAST GUARD NEW LONDON CT RESEARCH AND DEVELOPMENT CENTER
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This report documents a multi-year project effort to develop a specification for a light-emitting diode LED signal characteristic as an alternative to pyrotechnic, maritime distress signal flares as visual distress signals. The report includes the methodology used in evaluating color, flash pattern, and intensity for an LED distress signal, conspicuous against certain lighting conditions, at six nautical miles, in 10 miles meteorological visibility. The effort included a literature review, measurement and quantifying different levels of background lighting to recreate their effect in a vision laboratory, a series of laboratory tests to determine signal conspicuity in a controlled environment, and a field test in the marine environment. The human-subject laboratory experiments determined relative LED signal conspicuity, based on subjects accurate identification of a signal and the response time to make that identification. The lab results conspicuous signal characteristics were the basis for field testing. In addition to LED signals, the human-subject field test included two, commercial, off-the-shelf COTS signal devices and a handheld pyrotechnic flare in the signal evaluation. In four nights of testing, the experimenters produced a signal characteristic that was significantly more conspicuous than the flare and the two COTS devices.
- Electrooptical and Optoelectronic Devices
- Escape, Rescue and Survival