Night imaging systems based on image intensification (12) tubes
are a major factor in the night operation capability of military aircraft. A
major problem associated with the use of these systems is the detrimental
effect on performance caused by internal cockpit lighting. Instrument lamps,
caution lamps, utility lights, and other light sources inside the cockpit
activate the automatic gain control circuits of the intensification tubes,
thereby reducing their sensitivity to external natural and artificial illumination.
In 1986, a tn-service specification, MIL-L-85762, "Lighting, aircraft,
interior, night vision imaging system compatible," was adopted to resolve
the cockpit lighting problems. MIL-L-85762 defines the measurement instrumentation
and techniques required to certify lighting components as
"Night Vision Imaging System (NVIS) compatible." Ongoing efforts related
to MIL-L-85762 include characterization of lighting incompatibilities in current
U.S. Army aircraft, implementation of programs to modify the lighting
in incompatible cockpits, and certification of proposed lighting components
for future aircraft systems.