As of Version 7.0, ToAuthalicRadius has been renamed to "AuthalicRadius" and has become a property of GeodesyData.

gives the radius of the authalic sphere based on the spheroid with semimajor axis semimajor and eccentricity eccentricity.


  • To use ToAuthalicRadius, you first need to load the Geodesy Package using Needs["Geodesy`"].
  • The simplest way to convert from a spheroid to a sphere is to use the authalic sphere.
  • The authalic sphere has the same surface area as the reference spheroid.