Instruction manual

20. CHANGING THE SETTINGS
106
& Collimation correction
The OS has a collimation correction function that automatically corrects horizontal angle errors
caused by horizontal axis and leveling axis errors.
& Sea level correction
The OS calculates horizontal distance using slope distance values. As this horizontal distance
does not take height above sea level into consideration, performing spherical correction is
recommended when measuring at high altitudes. Spherical distance is calculated as follows.
Where: R = radius of the spheroid (6372.000m)
H
a
= averaged elevation of the instrument point and target point
d
1
= horizontal distance
& V mode (vertical angle display method)
Spherical distance
RHa–
R
------------------
d
1
×=
Zenith Horiz
Horiz 90°