This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
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As of Version 7.0, has been renamed to 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.
  • 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.