cal plane perpendicular to the bar axis. 
In the developed technique there are no 
constrains on the substance bar axis. 
As a result one can expect that the accuracy 
of the inserts co-ordinates by using the 
developed technique are better than those ob- 
tained by using surveying technique. 
Comparison Between the Developed Technique 
and the Photogrammetric Technique 
The accuracy of the inserts có-ordinates ob- 
tained by using the developed technique and 
the photogrammetric technique are functions 
of the accuracy of the image co-ordinates. 
A one second theodolite gives an accuracy in 
the co-ordinates of the theodolite image of 
t 0.5 microns for a 100 mm principal distance. 
This cannot be achieved by using real photo- 
graphs. 
116 
As a result, the accuracy of the image co- 
ordinates in the developed technique is better 
than in photogrammetric technique. Consequent- 
ly, the inserts co-ordinates obtained from the 
developed technique are more accurate than 
those obtained from the photogrammetric tech- 
nique. 
ACKNOWLEDGEMENTS 
The author is grateful to the University of 
Petroleum & Minerals for their support during 
the preparation and presentation of this paper. 
REFERENCES 
Abdel-Aziz and Karara 1974 "Photogrammetric 
Potentials of Non-Metric Camera" Civil Engi- 
neering Studies, Photogrammetry Series No. 36. 
University of Illinois, U.S.A.