Zoom | 242Technical Data
Slope distance
Horizontal distance
SD Displayed slope distance [m]
D0 Uncorrected distance [m]
ppm Atmospheric scale correction [mm/km]
mm prism constant [mm]
HD Horizontal distance [m]
YSD * sinζ
XSD * cosζ
ζ = Vertical circle reading
A (1 - k/2)/R = 1.47 * 10-7 [m-1]
k = 0.13 (mean refraction coefficient)
R = 6.378 * 106 m (radius of the earth)
SD
= D
0
· ( 1 + ppm · 10
-6
) + mm
HD
= Y - A · X · Y