-1 0 1 p-1 p p+1 n n+1 
mmm Se a3 77777 7 
Hn | | | 
I | | | 
A i | l I 
| | | | 
| 17 241 21 n 
! I I 
| | ! I 
| ! l | A 
Hr l I | | 
KR rio: Bus orroc 61 
  
  
  
  
  
  
Fig. 1. Location and notation of the photographs and control points of a triangulation 
strip. The triangles are control points in planimetry and the squares in elevation. 
1. The stereo-radial triangulation 
l.l. Basic formulae for single image pairs of photographs 
If the image coordinates a’, y' and x^", y" of corresponding details in 
two overlapping, exactly vertical aerial photographs (fig. 2) are measured 
the coordinates x, of intersected points can be determined from the 
expressions 
by" 
y FY (2) 
, LÀ r T 
xy —4 X 
The scale of the x, y-system is determined by the base b. Systematic 
radial errors of the image coordinates, caused for instance by radial 
o 
y A 
fil 
\ 
a 
   
  
ER A] 
Fig. 2. Numerical intersection of a point (xy) from the image coordinates (2 ^s/^), (zy?) 
in two overlapping vertical photographs.