Before revision: Ellipsoidal Earth projected to a plane The above formula is extended for ellipsoidal Earth: , where and are the meridional and its perpendicular, or "normal", radii of curvature of Earth (See also "Geographic coordinate conversion" for their formulas).
After revision: Ellipsoidal Earth formulae The above formula is extended for ellipsoidal Earth: , where and are the meridional and its perpendicular, or "normal", radii of curvature of Earth (See also "Geographic coordinate conversion" for their formulas).