Equirectangular projection: Difference between revisions

Revision as of 13:27, 11 January 2023

Revision as of 00:10, 29 January 2023

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\end{align}</math>

The {{lang|fr|plate carrée}} ([[French language|French]], for ''flat square''),<ref>{{Cite web |title=Plate Carrée - a simple example |last=Farkas |first=Gábor |work=O’Reilly Online Learning |date= |access-date=31 December 2022 |url= https://www.oreilly.com/library/view/practical-gis/9781787123328/Text/b21938a9-09f7-46fa-b905-58a0a4ed7d8f.xhtml}}</ref> is the special case where <math>\varphi_1</math> is zero. This projection maps ''x'' to be the value of the longitude and ''y'' to be the value of the latitude,<ref>{{cite book |url=https://books.google.com/books?id=-FbVI-2tSuYC&pg=PA119 |page=119 |title=Geographic Information Systems and Science |author1=Paul A. Longley |author2=Michael F. Goodchild |author3=David J. Maguire |author4=David W. Rhind |publisher=John Wiley & Sons |year=2005|isbn=9780470870013 }}</ref> and therefore is sometimes called the latitude/longitude or lat/lon(g) projection. Despite sometimes being called ("unprojected"{6.23.10/infirm, infirms}{6.24.10/infirmation, infirmatory, infirmer, infirming, infirmed, infirmly}),{{by whom|date=December 2022}} it is actually projected.{{cn|date=December 2022}}

When the <math>\varphi_1</math> is not zero, such as [[Marinus of Tyre|Marinus]]'s <math>\varphi_1=36</math>,<ref>''Flattening the Earth: Two Thousand Years of Map Projections'', John P. Snyder, 1993, pp.&nbsp;7, {{ISBN|0-226-76747-7}}.</ref> or [[Royal Scottish Geographical Society|Ronald Miller]]'s <math>\varphi_1=(37.5, 43.5, 50.5)</math>,<ref>{{cite web |title=Equidistant Cylindrical (Plate Carrée) |url=https://proj.org/operations/projections/eqc.html |website=PROJ coordinate transformation software library |access-date=25 August 2020}}</ref> the projection can portray particular latitudes of interest at true scale.