What is the elevation factor value for Earth’s radius R = 20,906,000 ft and local elevation H = 6,320 ft?

• A. 0.999697785
• B. 0.9997
• C. 1.000000000
• D. 0.980000000

Answer: (A)

The elevation factor comes from comparing distances on a curved Earth at the surface to distances measured from a point elevated by H. The relevant ratio is the radius at sea level divided by the radius at the elevated point: M = R / (R + H). This uses the idea that at height H, the effective radius is larger, so distances scale slightly down.

Plugging in the numbers: R + H = 20,906,000 + 6,320 = 20,912,320 ft. So M = 20,906,000 / 20,912,320 ≈ 0.999697785. Since H is small compared to R, the factor is very close to 1, just slightly less than 1.