Further is 
h? p x? h? + (x — b)? 
nus CE m 
  
  
. d 2 viet ely sl 7 
b 2 (7) 
The model deformation owing to the tilt e has the character of a para- 
bolic cylinder parallel with and symmetrical to the y-axis. 
3.5 Height Correction and Vertical Parallax Nomograms 
A mathematical treatment of the problem in question would have to 
be based upon the formula for lens distortion, and it would be a very 
troublesome and tedious business. The present problem is really a tech- 
nical one which on practical grounds should be solved by graphical 
methods [1], [14]. The graphical treatment, however, is applied in 
association with the purely mathematical deduction. The height cor- 
rections are converted into a millesimal of the flying height and the 
vertical parallaxes are determined at the scale of the photographs. The 
values of overlap are limited to 60 and 65 %. 
In addition to that the Aviogon camera alone has been treated in ana- 
logous way for an overlap of 65 96. The Aviogon lens distortion is 
shown in fig. 5. 
The height correction nomograms are shown in figs. 6—8. As 
expected the maximal height corrections of the Aviogon camera -+ 
infra filter are considerable within the area measured. The flying height 
of 4000 m will give a theoretical correction of 16 respectively 17 m 
which is well accordant with the value above mentioned, see item 3.1. 
The height analogous corrections of the Aviogon camera alone are 
about 0.85 m. 
The vertical parallax nomograms — figs. 9—11 are of parti- 
cular interest. As a special study the parallaxes along the principal ver- 
tical, i. e. the perpendicular to the base through the principal point are 
indicated diagrammatically. The most striking quality is the near recti- 
linear shape of these curves. As already mentioned in item 3.4, the 
effect of a change of e will be a rectilinear superimposition of this 
curve. The surfaces streaked in the figures is the only residuum of the 
original vertical parallaxes. 
This characteristic is the very explanation of the fact that the tilt e of 
the relative oriemtation results in a stercoscopical model, practically free 
from vertical parallaxes. 
  
3.51 Calculation of the Nomograms 
Before the starting of the calculation of the vertical parallax nomo- 
grams a study of the parallaxes along the principal vertical has been of 
interest as to their approaching to the principal point. 
15