Plate Carrée (Simple Equidistant Rectangular Projection)
Sep 24,2026

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Introduction

Plate Carrée (Simple Equidistant Rectangular Projection) is one of the most basic cylindrical projections. It directly maps the Earth's longitude and latitude at equal intervals onto a planar rectangular coordinate system—that is, longitude linearly corresponds to the horizontal axis and latitude linearly corresponds to the vertical axis—forming a rectangular grid with a 2:1 aspect ratio. This projection is extremely simple to compute, but area and shape distortion are very severe at high latitudes. Historically, it was therefore mainly used for early world map production and, in modern times, for panoramic textures and raster geographic data storage.

Projection Basic

The Plate Carrée treats the Earth as a sphere and covers the spherical surface with a graticule composed of meridians and parallels. It then projects each meridian at equal intervals onto the vertical direction of the plane and each parallel at equal intervals onto the horizontal direction of the plane, so that the longitude of any point on the sphere directly corresponds to the horizontal coordinate on the plane and the latitude directly corresponds to the vertical coordinate. In essence, it flattens longitude and latitude values into a rectangle without any nonlinear transformation.

Pros

Extremely simple computation: Longitude directly corresponds to the horizontal coordinate and latitude to the vertical coordinate, requiring no complex nonlinear transformation formulas. It is very convenient for both programming implementation and manual drawing.
Intuitive correspondence between coordinates and pixels: Each pixel has a one-to-one linear relationship with geographic coordinates (longitude and latitude), making it highly suitable for raster data storage, indexing, and display. It is therefore the default projection in many GIS software packages.
No length distortion along meridians: It remains equidistant along meridians (north-south direction), so distance measurements in the meridian direction are accurate.
Good uniform sampling characteristics: In digital media fields (such as VR panoramic video and 360° panoramic images), it enables uniform sampling mapping from sphere to plane, with a 2:1 aspect ratio covering a complete 360° view.
Relatively small distortion at low latitudes: Near the Equator (within about 30° north and south), shape and area distortion are relatively limited, making it suitable for rough mapping of low-latitude regions.

Cons

Extremely severe distortion at high latitudes: As latitude increases, the parallel direction is greatly stretched. Length distortion reaches 100% at 60° latitude and 474% at 80° latitude. Polar regions can hardly be represented correctly (the poles are stretched into straight lines as long as the Equator).
Neither conformal nor equal-area: Both angular and area distortion are significant, making it unsuitable for applications requiring preservation of direction or area accuracy (such as marine navigation and cadastral mapping).
Obvious shape distortion: Geographic features in high-latitude regions appear severely stretched horizontally, resulting in significant overall shape distortion.
Unsuitable for high-precision mapping and navigation: Due to projection-induced distortion, it cannot be used for marine or aviation navigation or large-scale topographic mapping that requires high geometric accuracy.

Application Scenario

Because of its simple computation and linear coordinate correspondence, the Plate Carrée is widely used in GIS for raster data storage and rapid browsing, for spherical unwrapping and mapping of 360° panoramic images and VR video, and for rough global visualization in early world maps and web map tile services. It is also commonly used in scenarios such as climate data and remote sensing imagery that require fast loading and uniform grid sampling. However, due to severe distortion at high latitudes, it is generally not used in professional fields requiring precise measurement or high-precision mapping.