By 
John W. Hardy 
H. Ronald Johnston 
John M. Godfrey 
Itek Corporation 
10 Maguire Road, Lexington, Massachusetts 
Ems Se 
Presented at the 
International Congress of Photogrammetry 
Lausanne, Switzerland 
July, 1968 
an 
ELECTRONIC CORRELATOR 
for the 
PLANIMAT