As of Version 7.0, SemimajorAxis has become a property of GeodesyData.

is an option for SpheroidalDistance which specifies the length of the semimajor axis in the spheroidal model.


  • To use SemimajorAxis, you first need to load the Geodesy Package using Needs["Geodesy`"].
  • SemimajorAxis->length specifies that the length of the semimajor axis of the spheroid is length kilometers.
  • The default setting, representing Earth, is 6378.14, from the WGS84 standard.