Secure lighting definition
Filters for secure lighting
NVG lighting for military vehicles introduces another requirement – secure lighting. This means that the lighting on instrument panels and elsewhere is modified so as to minimize detectability by NVG equipped enemy forces, while at the same time providing a degree of compatibility with NVGs within the vehicle.
The latter could be older Gen II devices, and would usually not be equipped with the sharp cut filter used on aviators’ NVGs. This means that compatibility must be achieved not only by control of wavelength of emissions, but also by control of brightness, to a much greater extent than in an aircraft cockpit.
Secure lighting is defined by the US Army CECOM (Communications – Electronics Command) in a set of guidelines, as follows.
- Wavelength restriction. Total energy over specific wavelength bands is controlled to defined limits so as to minimise red and infra-red outputs while retaining enough visible output to be usable to the unaided eye.
- Luminance reduction. Light sources should be dimmed below a specific level for night use, but still provide full brightness in daylight.
- Viewing angle restriction. The viewing angle should be less than a specific angle so it is only visible to personnel directly in front of it.
Consolite can provide filters suitable for these requirements, and can test light sources for compliance with requirements in its dark room test facility.