X = + 0.42 mm, my = + 0.32 mn, m, = + 0.75 mm, 
average average average 
m = + 0.62 mm, my = + 0.49 mn, m, : = + 0.97 mm. 
max imum max i mum max i mum 
Even though these results fell far short of the required accuracy 
level, the attainable precision permitted the use of the photo- 
grammetrically deduced data for the determination of the x- and 
y- in-plane displacements in all ranges of loading, and the z - 
deformations in the plastic range only. The structural group 
considered the accuracy of z much too coarse for used in the 
evaluation of the deformations and the deduction of the curva- 
tures in the elastic range. 
3.5. Preliminary Investigations 
  
In an effort to explore all the avenues to increase the 
accuracy of the stereometric systems to allow full utilization 
of the photogrammetrically deduced deformations, theoretical and 
experimental investigations (Karara, 1966) were conducted. The 
theoretical studies were based on mathematical models simulating 
stereometric coverages computed for a fictitious stereometric 
camera (essentially composed of the metrical chambers of the 
ZEISS SMK-40 and allowing degrees of freedom for convergence, 
tilt, and base length). In the experimental test, a ZEISS 
SMK-40 was used. Normal cases with b = 80 cm and b = 120 cm, 
as well as convergent and tilted photography were simulated 
using only one of the SMK chambers at a time. 
As reported in Tokyo in detail, (Karara, 1966), both the 
theoretical and the experimental results seemd to indicate that 
a substantial increase in precision of the system (in X,Y, & Z) 
was experienced as the convergence ( X in Fig.20) was increased 
o O à 
from 0° to 60°. The precision seemed to decrease, however,