Positioned within the casing 52 is {HEAD ~ a main optical housing} 56, a detector dewar 58, a scanner 60, an imager housing assembly 62, {TAIL ~ switching motor mechanism} 64 and the reflecting assembly switching assembly 66 
Positioned within the casing 52 is { HEAD ~ a main optical housing } 56 , a detector dewar 58 , a scanner 60 , an imager housing assembly 62 , { TAIL ~ switching motor mechanism } 64 and the reflecting assembly switching assembly 66
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