Azimuthal Equidistant

Azimuthal equidistant is a map projection in which all distances measured from the center of the map along any longitudinal line are accurate, however, distances and directions to all places are true only from the center point of projection. Distance measurements are accurate between points along straight lines through the center. All other distances are distorted and thus incorrect. Distortion of areas and shapes increases with distance from the center point.

This projection is used by the USGS in the National Atlas of the United States of America, and for large-scale mapping of Micronesia. It is used for polar mapping, airline route charting, and seismology, among other areas. The following graphic is an example of a map of the world projected in Azimuthal Equidistant (World Azimuthal Equidistant).

More Information

• The Nomenclature and Classification of Map Projections Empire Survey Review No. 51, Vol VII January 1944 Pages 190-200 ; L.P. Lee, Lands Survey Department, Wellington, N.Z.
• Matching the Map Projection to the Need
• List of ESRI-supported map projections
• Weisstein, Eric W. Map Projections. From MathWorld--A Wolfram Web Resource.
• Map Projections. Atlas of Canada.
• Cartographical Map Projections, Carlos A. Furuti website, www.progonos.com.
• Elements of Map Projection. (26 MB download) U.S. Coast and Geodetic Survey, Special Publication 68 (1938).
• Map Projections. USGS Publications. December 2000.
• What are map projections? ArcGIS 10 Online Help
• University of Colorado at Boulder - Map Projection Overview with Illustrations
• Data Projections. GeoCommunity Web site.
• Wiki.GIS.com - Types of Projections