Equirectangular projection: Difference between revisions

Revision as of 12:56, 8 January 2023

Revision as of 15:17, 10 January 2023

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[[File:Plate Carrée with Tissot's Indicatrices of Distortion.svg|thumb|upright=1.75|Equirectangular projection with [[Tissot's indicatrix]] of deformation and with the standard parallels lying on the equator]]

[[File:Blue Marble 2002.png|thumb|upright=1.75|True-colour satellite image of Earth in equirectangular projection]]

The '''equirectangular projection''' (also called the '''equidistant cylindrical projection''' or '''la carte parallélogrammatique projection'''), and which includes the special case of the '''plate carrée projection''' (also called the '''geographic projection''', '''lat/lon projection''', or '''plane chart'''), is a simple [[map projection]] attributed to [[Marinus of Tyre]], who [[Ptolemy]] claims invented the projection about AD 100.<ref>''Flattening the Earth: Two Thousand Years of Map Projections'', John P. Snyder, 1993, pp.&nbsp;5–8, {{ISBN|0-226-76747-7}}.</ref> The projection maps [[meridian (geography)|meridians]] to vertical straight lines of constant spacing (for meridional intervals of constant spacing), and [[circle of latitude|circles of latitude]] to horizontal straight lines of constant spacing (for constant intervals of [[circle of latitude|parallels]]). The projection is neither [[equal-area mapprojection|equal area]] nor [[conformal map projection|conformal]]. Because of the distortions introduced by this projection, it has little use in [[navigation]] or [[cadastral]] mapping and finds its main use in [[thematic map]]ping. In particular, the plate carrée has become a standard for global [[geographic information system|raster datasets]], such as [[Celestia]], [[NASA World Wind]], the [[USGS]] [[Astrogeology Research Program]], and [[Natural Earth]], because of the particularly simple relationship between the position of an [[pixel|image pixel]] on the map and its corresponding geographic ___location on Earth or other spherical solar system bodies. In addition it is frequently used in panoramic photography to represent a spherical panoramic image.<ref>{{cite web |title=Equirectangular Projection - PanoTools.org Wiki |url=https://wiki.panotools.org/Equirectangular_Projection |access-date=2021-05-04 |website=wiki.panotools.org}}</ref>

==Definition==