What is the semi-major radius of Clarke's ellipsoid of 1866?

Clarke's ellipsoid of 1866 is a mathematical representation of the Earth's surface used in geodesy. The semi-major axis, which is the longest radius of the ellipsoid, is a critical parameter in various geodetic calculations and mapping applications. In the case of Clarke 1866, the semi-major radius is defined as 6,378,206 meters.

This specific value is derived from historical measurements and has been widely adopted in geospatial sciences, serving as the foundation for various surveying and mapping tasks. Its significance lies in providing a standardized reference for geodetic work in North America and other regions during its time of use.

Understanding this measurement helps to ensure accuracy when dealing with calculations involving latitude, longitude, and elevation in relation to the Earth's geometry. The precise value of the semi-major axis is essential for applications such as GPS technology, land surveying, and geodetic engineering.