Tissot's Indicatrix

Tissot's indicatrix - [map projections] A graphical representation of the spatial distortion at a particular map location. The indicatrix is the figure that results when a circle on the earth's surface is plotted to the corresponding point on a map. The SHAPE / Shape, size, and orientation of an indicatrix at any given point depend on the map projection used. In conformal (SHAPE / Shape-preserving) projections, the indicatrix is a circle; in nonconformal projections, it is an ellipse at most locations. As a visual aid, indicatrices convey a general impression of distortion; as mathematical tools, they can be used to quantify distortion of scale and angle precisely. The indicatrix is named for Nicolas Auguste Tissot, the French mathematician who developed it.

[Category=Geospatial ]

Source: esri, 13 September 2012 09:54:56, http://support.esri.com/en/knowledgebase/GISDictionary/term/abbreviation