GIS Dictionary

Definitions for GIS terms related to operations such as analysis, GIS modeling and web-based GIS, cartography, and Esri software.

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eccentricity

  1. [Euclidean geometry] A measure of how much an ellipse deviates from a circle, expressed as the ratio of the distance between the center and one focus of an ellipsoid to the length of its semimajor axis. The square of the eccentricity (e2) is commonly used with the semimajor axis a to define a spheroid.
    eccentricity Illustration