The Earth is a geoid with a very complex shape.
Its diameter is 12 756 km at the equator.
It is inclined at 23°27' to the normal to the Plane of the Ecliptic.
The Earth is made of Parallel and Meridians.
A point on the Earth is located using the Latitude and Longitude.
The main unit of length in navigation is the Nautical Mile.
Status:: #wiki/notes/embryo
Plantations:: Navigation, Solar System
References:: Le Manuel de Pilotage d'Avion