23.09.2011
geographic coordinates on shpere and
ellipsoid of revolutionThe axis are:
- the reference meridian or zero meridian
(in the XZ- plane)
- the equator (in the XY- plane)
- the perpendiculars on the surface*
The coordinates are:
- latitude
[phi]
(-90° - +90°)
- -90° S: south pole
- +90° N: north pole
- -90 °S - 0°: southern hemisphere
- 0° - +90°: northern hemisphere
longitude 
[lamda]
(- 180° - +180°)
-180° W - 0°: western hemisphere
0° - 180° E: eastern hemisphere
height h (spherical or ellipsoidal
height/altitude/depth)*
The coordinate lines are:
- parallel: line of constant latitude
- meridian: line of constant longitude
The mapped image of the parallels and meridians is called
graticule.-----
* geographic coordinates often are 2D only
