8 
by the so-called y-parallax-method developed by Hallert [12]. Both methods 
use the stereo model itself as test object. In the first method horizontal and in 
the second vertical parallaxes are measured. None of the methods provides 
principal point or camera constant. 
Bergenvik [2] has derived a method to determine interior orientation based 
on projective relations between planes. Two oblique pictures are taken over an 
area with four points located on one plane. The horizon lines of the two pictures 
have to intersect, if possible at right angles. 
Cameras for ballistics and satellite tracking are calibrated using the stars as 
targets [4]. The calculation procedures are similar to those in this thesis, but 
the test targets are infinitely distant which means that the co-ordinates of the 
exterior projection center must not be introduced as unknowns. However, for 
close-up cameras, because the targets must be located at finite distances, it be 
comes necessary to introduce parameters for the co-ordinates of the exterior 
projection center. 
Fig. 1. 
The first three-dimensional test object used by the author to determine the interior orien 
tation of a Stereo-Palmos with Tessar lenses f = 90 mm. The dimensions of the test object 
are 50 x 160 x 200 mm, which correspond to actual object sizes.