azimuthal equidistant projection
American Heritage Dictionary:
Top
azimuthal equidistant projection
n.
A map projection of the earth designed so that a straight line from the central point on the map to any other point gives the shortest distance between the two points.
Related Videos:
Top
azimuthal equidistant projection
Random House Word Menu:
Top
categories related to 'azimuthal equidistant projection'
- Maps and Cartography - azimuthal equidistant projection: map projection in which great circles projected through a central point provide shortest distance from center to any point; zenithal equidistant projection
Wikipedia on Answers.com:
Top
Azimuthal equidistant projection
The azimuthal equidistant projection is a type of map projection. A useful application for this type of projection is a polar projection in which all distances measured from the center of the map along any longitudinal line are accurate; an example of a polar azimuthal equidistant projection can be seen on the United Nations flag.
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 useful for showing airline distances from center point of projection and for seismic and radio work.
Distances and directions to all places are true only from the center point of projection. Distances are correct between points along straight lines through the center. All other distances are incorrect. Distortion of areas and shapes increases dramatically, the further away one gets from center point.
Some types of wide-angle camera lenses, known as "fisheye lenses" produce an azimuthal equidistant projection of the photographed scene onto the photographic medium. These lenses allow a much wider field of view than perspective lenses, which are limited to significantly less than 180 degrees.
History
While it may have been used by ancient Egyptians for star maps in some holy books,[1] the earliest text describing the azimuthal equidistant projection is an 11th-century work by al-Biruni.[2]
In some countries this projection is named "Postel projection" after Guillaume Postel, who used it for a map in 1581.[1]
References
- ^ a b SNYDER, John P. (1997). Flattening the earth: two thousand years of map projections. University of Chicago Press. ISBN 0-226-76747-7., p.29
- ^ David A. KING (1996), "Astronomy and Islamic society: Qibla, gnomics and timekeeping", in Roshdi Rashed, ed., Encyclopedia of the History of Arabic Science, Vol. 1, p. 128–184 [153]. Routledge, London and New York.
External links
- Table of examples and properties of all common projections, from radicalcartography.net
- Online Azimuthal Equidistant Map Generator
- An interactive Java Applet to study the metric deformations of the Azimuthal Equidistant Projection.
- GeographicLib provides a class for performing azimuthal equidistant projections centered at any point on the ellipsoid.
- Concept and mathematics of the Azimuthal Equidistant Projection for the marine navigator.
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Best of Web:
Top
azimuthal equidistant projection
Some good "azimuthal equidistant projection" pages on the web:
Post a question - any question - to the WikiAnswers community:
Copyrights:
American Heritage Dictionary
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
Read more
Random House Word Menu
© 2010 Write Brothers Inc. Word Menu is a registered trademark of the Estate of Stephen Glazier.
Write Brothers Inc.
All rights reserved.
Read more
Mentioned in
azimuthal equidistant chart
(mapping)
Great circle, terrestrial
(physical geography, geomorphology)
» More