With the aid of this expression and of earlier derived weight and correlation numbers, the expression 
for accuracy of height measurements in the various parts of the stereo-model may be established. 
Considering the law of propagation for standard errors, one obtains: 
2 2 2 
= x .- ]J^.- x.rd.dx ; ze l5]. 
“hn = (x-3 12 ) “yy « (3 214 & cu +2 b 5) 
JEL. 3.22 ( 
(5 211 %) LT am 
The standard error in height measurement is then obtained from 
Shr =A \/ nh (18) 
3.2. The influence of absolute orientation on accuracy of height measurements 
In the same way as in the system of equations (13), in the six elevation control-points the following 
correlations are obtained: 
  
C 
dh, = dh, (19a) 
dh + » an = dh (195) 
o 2 55 
dh, + b.d7) = dh, (19¢) 
dh + dà = h4 1 (194d) 
b 
dh, +5 an + d'df = ah (19e) 
dh, + b-dn + deaf = äh, (19f) 
ç 
The equations provide the following solution: 
1 
df = «=f ( dh, *dh,,  dh,, - dh - dh, - anys ) (208) 
1 
= i - ) 
47 = x dh, + dh,, - dh,, + any ) (20b) 
1 
an, = Iz (zäh, Häh,, + dh,, +3dh,, Bas) (20c) 
From this we obtain the following weight and correlation numbers: 
1 1 2 Y 
Q m oe Q = —— Q = — (21a)-(21c) 
hoh, + 12 NN v? EE 3a? ) 
1 1 
Q _=-— Q =-—  Q = 0 (21d)-(21f) 
hon 2b hs 3d né 
and 
2 2 
ee d D 2y x x (22) 
uh FT t T$ ^33 
In the san 
Se = 1 
Where # 
3.5. The ! 
For accure 
ii 
and 
hi = 76, 
Total star 
S 
Average ac 
the limits 
  
The variat 
value of € 
In compari 
31, 39, 51 
obtained 1 
For e = OC, 
The appear 
accuracies 
For compar 
designed 1 
points in 
Literature 
1) Hallert 
2) Kvarnbr 
in Aeri 
3) Ohlin, 
of Extr