Assuming the radius of the Earth is 20,906,000 ft, what is the ellipsoid distance for a distance measured as 2,500 ft at a mean ellipsoid height of 1,600 ft?
Explanation
Answer: B - The ellipsoid distance for a distance measured as 2,500 ft at a mean ellipsoid height of 1,600 ft is 2,499.81 ft.
Solution
Use the geodetic distance equation:
Geodetic distance = (Radius to ellipsoid / Radius to surface) x measured distance at the surface
Where Radius to ellipsoid = 20,906,000 ft
Radius to surface = (20,906,000 ft + 1,600 ft) = 20,907,600 ft
Measured distance = 2,500 ft
Geodetic distance = (20,906,000 ft / 20,907,600 ft) (2,500 ft)
= 2,499.81 ft
