The sensor head 14 wherein {HEAD ~ said first reflecting means} is said {TAIL ~ afocal three mirror anastigmat}, the mirrors of said three mirror anastigmat being coupled with said optical housing and said switching assembly 
is
The sensor head 14 wherein { HEAD ~ said first reflecting means } is said { TAIL ~ afocal three mirror anastigmat } , the mirrors of said three mirror anastigmat being coupled with said optical housing and said switching assembly
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH