Atmospheric Refraction And Earth Curvature Correction - Pentax W-800 Series Basic Instruction Manual

6.4 Atmospheric refraction and earth curvature correction

• Atmospheric refraction and earth curvature correction refers to correcting both the
bending of the light beam caused by atmospheric refraction and the effect on the height
differential and horizontal distance caused by the earth curvature.
• Correction called "atmospheric refraction and earth curvature correction" is initiated to
correct error when the slope distance and vertical angle are caused to determine the
horizontal distance and the height differential, with this instrument, the following formula
is used to correct these factors.
• Calculation formula when atmospheric refraction and earth curvature correction
parameter is set to "ON":
Corrected horizontal distance (H)
Corrected vertical distance (V)
• Calculation formula when atmospheric refraction and earth curvature correction
parameter is set to "OFF":
S: Slope distance
α:
Vertical angle from horizontal
K: Atmospheric refraction coefficient (0.14 or 0.2)
Re: Diameter of earth 6378137m
44