37 
1 
diy = —3j —Pa +D3 —Pa +Ps—Pe) — 
1 
-37la — 2 +K(23 E. T As — £) ]do, 
1 
do; E —p4—ps tfe) + 
K 
topi s "24725 +26) do (4a) 
1 K 
dbz, 79g — fe) toga — Ze) door 
1 1 
dby; 73 +Pa+Pe) tale 4 K(z4 t zg) doy; 
u( —2p,-- pa - ps) -v( —2pa ba Do) 
  
do = 
  
where 
K=1+k 
u =22, — K(23 +25) (4b) 
y —2z$3— K(z4 £g) 
The »-parallax p is defined as 
b — dy, — dyy (5) 
The relation between the errors in the projection of corres- 
ponding rays and errors in the model coordinates is: 
dx = — En T dar 
dy = (dx; — day) + (1 —S) dy, + Sd (6) 
de = — 5 (der — den) 
S is the ratio of the distance from the left projection to the 
observed point in relation to the distance between the two pro- 
jections. With a symmetrical setting $ —0,5. 
The relation between errors in the outer orientation elements 
and errors in the model coordinates is given by the formulae: