Topic summary
Geodetic latitude
Extracted from the Wikipedia article Geodetic coordinates.
Geodetic vs. geocentric coordinates
Geodetic latitude and geocentric latitude have different definitions. Geodetic latitude is defined as the angle between the equatorial plane and the surface normal at a point on the ellipsoid, whereas geocentric latitude is defined as the angle between the equatorial plane and a radial line connecting the centre of the ellipsoid to a point on the surface (see figure). When used without qualification, the term latitude refers to geodetic latitude. For example, the latitude used in geographic coordinates is geodetic latitude. The standard notation for geodetic latitude is φ. There is no standard notation for geocentric latitude; examples include θ, ψ, φ′.