1 article for "Geographic Coordinates"

Geographic Longitude and Latitude. Longitude is measured east and west from the Prime Meridian (the meridian of the old Greenwich Observatory) to the observer's meridian; Latitude is measured by the angle between the observer's plumb bob and the plane of the equator: + if north, - if south. See Figure C1.

See also:
♦ Longitude ♦ Meridian ♦ Latitude