Specifications

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B. Emission points
Emission points are steady or uctuating pinpoints of bright light in the image area that do not go away
when all external light is blocked from the objective lens (Figure 4-3). The position of an emission point
withintheimageareadoesnotmove.NotallemissionpointsarecausetoreturntheSirius.Verifythat
emission points are not simply light sources present in the scene you are observing. Emission points are
acceptableiftheydonotinterferewiththeuser’sabilitytoperformmissions.
BRIGHT
SPOT
EMISSION
POINT
FIGURE 43. EMISSION POINTS AND BRIGHT SPOTS
C. Black Spots
Black spots are cosmetic blemishes in the image intensier or debris between the lenses. Black spots
areacceptableaslongastheydonotinterferewiththeuser’sabilitytoobservethescene.Noaction
isrequiredifthisconditionispresent,unlessthespotsinterferewiththeoperator’sabilitytoperform
missions.
D. Fixed-pattern Noise
Fixed-pattern noise is usually a cosmetic blemish characterized by a faint hexagonal (honeycomb) pat-
tern that appears throughout the viewing area. This typically occurs in excessively lit environments or
when viewing very bright lights (See Figure 4-4). This pattern can be seen in every image intensier if
the level of light is high enough. This condition is acceptable as long as the pattern does not interfere
withtheuser’sabilitytoviewanimageorinterferewiththeirabilitytoperformmissions.
FIGURE 44. FIXEDPATTERN NOISE
E. Chicken Wire
Chicken wire is an irregular pattern of dark thin lines that can appear in the eld of view, either through-
out the image area or in sections of the image area (See Figure 4-5). In the worst-case scenario, these
lines will form hexagonal or square-wave shaped lines. No action is required if this condition is present,
unlessitinterfereswiththeuser’sabilitytoviewtheimageortheirabilitytoperformmissions.
FIGURE 45. CHICKEN WIRE