5-6
4. Fixed-Pattern Noise
.
This is usually a cosmetic blemish charac terized by a faint hex-
agonal (honeyco mb) pattern t hroughout the viewing area tha t
most often occurs at high light levels or when viewing very bright
lights (See Figure 5-4). This pattern can be seen in every image
intensifier if the light l evel is high enough.
This conditio n is
acceptable as long as th e pattern d oes not int erfere wit h
viewing the image and inte rfere with the abili ty to perform
the mission.
Figure 5-4
Fixed Pattern Noise