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