Civil Engineering Studies 
Photogrammetry Series No. 15 
ON THE PRECISION OF STEREOMETRIC SYSTEMS 
By Dr. H.M. Karara 
Professor of Civil Engineering 
University of Illinois 
Urbana, lllinois 61801 USA 
A Report on a Study 
Sponsored by 
The National Science Foundation 
An Invited Paper of Commission V 
International Society of Photogrammetry 
Eleventh International Congress of Photogrammetry 
Lausanne, Switzerland 
July 1968 
University of Illinois 
Urbana, Illinois USA 
January 1968