uu Ves 
+ Xa5 + Vis — Vos — Vas Ÿ Vas 
N134 — yss + Vos + Y105 + Vais + 7(X65 — X75 + Xg5 — 
X95 — X195 Ÿ X115 — X425 d- X135) t 25(x45 — Xo5 —Xx; ; 
. Lux LE hg2 E. ae 3 J Y | AY d AT 
+ Xs + Vis Tt yes + Vas + Vas) + 49(yos t yss + Yizs + Viss) 
  
Ou 
The method has been put into practice at the Division of Photo- 
grammetry in Stockholm. The Autograph A 7 was tested with a very 
accurate grid. As an example of the investigation the distortion curve of 
the left projector is shown in diagram 4. 
c — 99,992 mm 
At this investigation the discrepancies are assumed to depend only 
upon errors in the elements of the inner and outer orientation of the 
projectors, radial distortion and the coordinate measurements. In in- 
struments with mechanical projection, for instance the Autograph A 7, 
also other errors can be present. In particular we have the lacking in- 
tersection of axes and the x-inclination and latitude distortion (Brei- 
ten- and Schiefen-errors). 
It is of course possible to express analytically the influences of such 
errors. For the x-inclination and latitude distortion the correction-equa- 
tions can be written as follows (see Lycken [5]): 
x y'h x x'y' (17) 
V cm dx de, d-— ded: hdg-- 
= > s e: hdo + 
230. + y' x 
E. dt + = dl — dx