436 
feet synchronizing with the main camera can occur as a mechanical 
defect. If it is supposed that mechanical defects and vibrations do not 
influence the standard error and that the standard error of the image 
coordinates in the horizon camera calibration is 0.005 mm, which gives 
an inclination of 0.44 c according to the formula (25), totally a theore 
tical standard error of s 0 = s Q = 
\/ 0.242 + 1.222 + 0.442 + 1.202 = 1.8‘ ; 
is obtained, where 1.20 c is the precision. Besides accidental errors even 
systematic errors influence in the horizon position. Both the refraction 
and the elevation variations of the horizon can influence systematically. 
In this case it can be thought that the elevations have had a systematic 
influence upon the longest strip. The systematic angle error in every 
photograph is denoted with dm«, the angle translation with da 0 , the 
base with b, and the distance from the middle line of the strip with a. 
The following differential formula is obtained between these data: 
(27) 
The corresponding correction equation is 
a 
v = — d«o — T~ dm a — da 
b 
(28) 
where 
lere da = a hk — a A8 
The following solution of normal equations is obtained: 
_ 
b[ada] 
(29) 
[da]2 [ada] 2 
If the numbers of the images in the strip are 1, 2 
n, the following formulas are obtained: 
i, 
[vv] = [da da] — 
n + 1 
a = ( 2 — i) b 
2[(n + 1 — 2i) da] 
dnia = [(n + 1 — 2i)2] 
[da] 2 [(n + 1 — 2i) da] 2 
(30)