Two levels of abstraction are employed in the definitions of latitude and longitude. In the first step the physical surface is … See more

The graticule is formed by the lines of constant latitude and constant longitude, which are constructed with reference to the rotation axis of the Earth. The primary reference points are the poles where the axis of rotat… See more

In 1687 Isaac Newton published the Philosophiæ Naturalis Principia Mathematica, in which he proved that a rotating self-gravitating fluid body in equilibrium takes the form of an oblate ellipsoid. (T… See more

The length of a degree of latitude depends on the figure of the Earth assumed.
On the sphere the normal passes through the centre and the latitude (ϕ) is therefore equal to the angle subtended at the centre by the meri… See more

There are six auxiliary latitudes that have applications to special problems in geodesy, geophysics and the theory of map projections:
• Geocentric latitude
• Parametric (or reduced) la… See more