Equidistant conic projection

The world on an equidistant conic projection. 15° graticule, standard parallels of 20°N and 60°N.

The equidistant conic projection is a conic map projection known since Classical times, Ptolemy's first projection being derived from it.[1]

The projection has the useful property that distances along the meridians are proportionately correct, and distances are also correct along two standard parallels that the mapmaker has chosen. The two standard parallels are also free of distortion.

The map projection is used most often in maps of regions elongated east-to-west (such as the continental United States), with the standard parallels chosen to be about a sixth of the way inside the northern and southern limits of interest. This way distortion is minimized throughout the region of interest.

See also

References

  1. Snyder, John P. (1993). Flattening the Earth: 2000 Years of Map Projections. University of Chicago Press. p. 11. ISBN 0226767469.

External links

This article is issued from Wikipedia - version of the Friday, September 11, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.