|
Searching and tracking at night can be enhanced using flashlights and body-mounted lamps with optimized illumination spectra while using less battery power. Benefits include improved situational awareness and more rapid identification of important detail, hazards, and surface conditions (e.g., water, ice, or oil films) for a wide range of both military and civilian personnel. Many complex natural surfaces appear as dark brown, grey, or black. Small spectral differences can be critically important for the identification of surface structures and objects. Improved visual object detail recognition is possible if differential color can be enhanced. Over 18,000 reflected spectral data measurements from natural terrestrial objects such as recently disturbed soils, ground clutter, foliage, bark, fungi, minerals, blood, and a wide variety of ground hazards have been collected and analyzed to predict the optimal spectra illumination for the tasks of visually differentiating color, topology, and detail in natural terrestrial objects and many other surfaces. This paper relates and summarizes a vast amount of reflected light data with human visual sensitivity. We found that broad-spectrum, over-90 CRI LED light sources with boosted cyan (480-510nm) and a wide range of visible reds (610-700nm) can better highlight differences in many darker-shade objects and most other surfaces better than cool-white, neutral, or warm-white LED flashlights and head-worn lamps typically used today even though the perceived “brightness” in lumens is lower for a given amount of illumination power.
|
