GIS Dictionary
Definitions for GIS terms related to operations such as analysis, GIS modeling and web-based GIS, cartography, and Esri software.
Now available for purchase: A to Z GIS: An illustrated dictionary of geographic information systems.
Search the GIS Dictionary:
GIS Bibliography
Researching GIS?
Search the GIS Bibliography for a vast index of books, journals, conference proceedings and reports.
geocentric coordinate system
-
[coordinate systems]
A three-dimensional, earth-centered reference system in which locations are identified by their x-, y-, and z-values. The x-axis is in the equatorial plane and intersects the prime meridian (usually Greenwich). The y-axis is also in the equatorial plane; it lies at right angles to the x-axis and intersects the 90-degree meridian. The z-axis coincides with the polar axis and is positive toward the north pole. The origin is located at the center of the sphere or spheroid. 
