Question

The combined correction due to curvature and refraction (in m) for a distance of 1 km on the earth surface of earth is

• A. 7.63
• B. 0.763
• C. 0.673
• D. 0.0673

Answer 1

The correct option is D 0.0673

The correction due to curvature of earth and the refraction can be combined into one composite correction.

$C=-0.0673d^2$

Where: d is in km; C is in m.

$\Rightarrow C=0.0673\times 1^2$

$=0.0673$