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:

  Search  

Browse the GIS Dictionary:

GIS Bibliography

Researching GIS?
Search the GIS Bibliography for a vast index of books, journals, conference proceedings and reports.

universal time

See Also: coordinated universal time

  1. [astronomy] A timekeeping system that defines local time throughout the world by relating it to time at the prime meridian. Universal time is based on the average speed at which the earth rotates on its axis. For official purposes, universal time has been replaced by coordinated universal time; universal time is, however, still used in navigation and astronomy. Different versions of universal time correct for irregularities in the earth's rotation and orbit.