ApproxAngularDistance returns the cosine of the angle between two points.

ApproxLinearDistance computes a distance across the surface of the Earth.

GeocentricLatitudeDifference returns geographic latitude - geocentric latitude (φ - φ′) given geographic latitude (φ).

OneDegreeOfLatitude returns the length of one degree of latitude.

OneDegreeOfLongitude returns the length of one degree of longitude.

Rho is distance from Earth center to a point on the ellipsoid at latitude φ.

RotationRate1996_5 is the rotational angular velocity of the Earth with respect to the stars at the epoch 1996.5.

IAU 1976 values.

Coord represents geographic coordinates on the Earth.

Ellipsoid represents an ellipsoid of revolution.