A reference or geographic control point for a coverage representing a known location on the earth's surface. Tics allow all coverage features to be recorded in a common coordinate system. Tics are used to register map sheets when they are mounted on a digitizer. They are also used to transform the coordinates of a coverage, for example, from digitizer units (inches) to the appropriate values for a particular coordinate system.
- Wade, T. and Sommer, S. eds. A to Z GIS: An illustrated dictionary of geographic information systems, Esri Press, 2006.
- What are tics?. ArcGIS Desktop 9.3 online help. Accessed 11 June 2010.