0 I ; ; » number of 
0 20 40 60 80 ipo models 
Fig. 4. Standard errors of the coordinates and elevations of open aerial triangula- 
tion strips of varying lengths. Only the first model is absolutely oriented. 
bi=—='d — 06h u=1 
In a strip, consisting of n models, a certain model can be determined 
by the factor a (0 < a < 1). The weight numbers of the coordinates 
and elevation of the point 2 of the model (an—1, an) are, with minor 
approximations, obtained as follows: 
O n3(a2 + a3 — 2a*) (2b? + d2) n? (a: (16) 
Lá - - — — — — + — - - 
By 6d? 
  
  
2at) . 4n(a — a2) (17) 
+ EN 
9 
  
  
  
  
  
  
  
ETE TEST EMEN ANTON AE TA FE EE