Spatial FOG Reference Manual
Page 18 of 144
Version 2.3
03/05/2018
5.8
Geodetic Co-ordinate System
The geodetic co-ordinate system is the most popular way of describing an absolute
position on the Earth. It is made up of the angles latitude and longitude combined with
a height relative to the ellipsoid. Latitude is the angle that specifies the north to south
position of a point on the Earth's surface. Longitude is the angle that specifies the east
to west position of a point on the Earth's surface. The line of zero latitude is the
equator and the line of zero longitude is the prime meridian. Illustration 4 shows how
latitude and longitude angles are used to describe a position on the surface of the
Earth.
Illustration 4: Latitude and longitude represented visually to describe a position
