à a 
tet iti iei d 
  
ie M ja 
  
   
   
  
   
  
  
  
  
  
   
  
   
   
  
  
  
   
   
     
   
    
   
   
      
  
: : É x Ss Sa RR i i 3 
t rient ls iii pre i iid 
  
  
systematic errors depend upon errors in the inner ang outer 
orientation only. It is obvious that there are also other 
sources of errors. In the Autograph A 7, which is an insti. 
ment with mecanical projection, there are for instance the 
"Breiten- and Schiefen" errors and the lacking intersection of 
of the movable parts may also cause errors and the method for 
testing the instruments can be extended to include also this 
kind of errors. The problem is only to study their influences 
upon the projected grid points and then to make the computation 
with more degrees of freedom, Also these problems have been 
treated at the Division of Photogrammetry. 
In most cases superflous observations are present, In 
practise the adjustment procedure, particularely the error pro- 
pagation, is more or less approximative as a result of the diffi. 
culty in detecting the systematic errors, The standard error of 
the measurements is, however, a good indicator of the precence 
of systematic errors not taken into consideration at the adjust- 
ments amounted to about 6 microns in the grid plane and the 
standard error of the distortion to about ^ microns, 
This investigation is only one of the first experiments to 
2 
etermine the systematic deformations of the pencils of rays of 
ej 
hotogrammetric plotters according to the method described above, 
HH 
Xtreme accuracy is desirable, however, it obviously gives a 
method to correct most of the systematic errors of the instruments 
5 
  
Deformations of the instrument as a result of the weight 
At this investigation the standard error of the measure-