PERFORMANCE AND APPLICATIONS OF ORTHOPHOTOMAPS 
J. Visser 
ITC, Netherlands 
L. van Zuylen 
ITC, Netherlands 
by 
M. C. van Wijk 3 
National Research Council of Canada 
R. Mullen 
U. $. Geological Survey, USA 
INTERNATIONAL SOCIETY FOR PHOTOGRAMMETRY 
COMMISSION IV 
Prepared for presentation at the XIIth Congress ISP 
OTTAWA, CANADA 
1972