^■«3 1 
VERT1C.VL PROJELCTIOH 
Sdrtryck ur Svensk Lantmateritidskrift nr 3 1964 
The Influence of the Curvature of the 
Earth upon Aerial Photographs 
K. A. Ohlin ) VIAK Consulting Engineers, Vallingby 
1 The magnitude of the curvature of the earth. 
According to the theorem of Pythagoras’ we have: 
f s 2 + (R + dH)2 = R2 (see fig. 1) 
\ s 2 ' = x 2 + y 2 (see fig. 2) 
From (1) and (2) we find: 
x 2 + y 2