Earth Ellipsoids Reference

Lookup up parameters of the most used ellipsoids.

Semi-major Axis A, m
Inversed Flattening
Semi-minor Axis B, m

An Earth ellipsoid approximates the Earth. The semi-major axis A (the equatorial radius) and semi-minor axis B (the polar distance) describe its shape. The flattening tells the equatorial radius compression relative to the equatorial radius. The inverse flattening is for convenience, it is a lot easier to write 298.25 than 0.00335289186923722.