
Computational Geodesy 29
FIGURE 2.3
Geodetic and geocentric latitude
2.5.3 Geocentric Latitude
Geocentric latitude of a point on the geoid is defined as the angle subtended by
the radius passing through that point and the equatorial plane. Refer to Figure
2.3. Let ‘O’ be the center of the geoid and ‘P’ be an arbitrary point on the
surface of the geoid. Therefore the angle subtended by OP with the equatorial
plane is the Geocentric latitude of that point. It is usually designated by the
symbol ψ (Greek small letter Psi). The relation between the geocentric latitude
(ψ) and geodetic latitude(φ) is given by the equation:
ψ(φ) = tan
−1
[(tan φ)(1 − e
2
)] (2.51) ...