A recognition light includes a reflector having an axis and first and second
annular
semi-parabolic reflective surfaces which have respective focal points axially spaced
apart from one another, and first and second annular lamps respectively disposed
at the focal points. A cover surrounds the reflector and lamps and includes a lens
for focusing the light along a plane perpendicular to the axis of the reflector,
the lens including first and second Fresnel lens portions each including a convex
lens and a prism lens, the convex lenses being disposed adjacent one another and
transaxially aligned with the first and second lamps, respectively. A light detector
detects light emitted from at least one of the lamps, a monitor circuit provides
a fail signal when a characteristic of the light output of at least one of the
lamps does not satisfy a specified criteria, and a control circuit first activates
the first lamp and then the second lamp in response to receipt of the fail signal
of the monitor circuit.