86 
  
  
ed 2 
M | Vmi+m | 
\ ry 
100 + 
5) À 
0 T T T T T i 
10 20 30 40 50 
Diagram 20. Numerical stereo-radial triangulation. Mean values of radial standard 
h 
errors. Bridging. s, — — 1. 
C 
4. Mean values of the radial standard errors of the points 
along the strip 
From the diagrams 16— 18 it is possible to determine mean values 
of the standard errors of the coordinates along the strips. From practical 
investigations of aerial triangulation procedures, the results are frequently 
demonstrated as mean square values of the diserepancies in check points 
along the strip. For comparison it therefore may be of interest to express 
the theoretical standard errors in a similar manner. 
For this purpose we use radial standard errors defined as the square 
root of the sum of the squares of the standard errors of the x- and y- 
coordinates. This expression can then be plotted in diagrams for differ-