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Equal Area Cylindrical

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Classification

Cylindrical

Available forms

Forward and inverse, spherical and ellipsoidal

Defined area

Global

Alias

cea

Domain

2D

Input type

Geodetic coordinates

Output type

Projected coordinates

+
+Equal Area Cylindrical +
+

proj-string: +proj=cea

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Named specializations

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The Equal Area Cylindrical projection is sometimes known under other names when +it is instanciated with particular values of the lat_ts parameter:

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Name

lat_ts

Lambert cylindrical equal-area

0

Behrmann

30

Gall-Peters

45

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+
+

Parameters

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+

Note

+

All parameters are optional for the Equal Area Cylindrical projection.

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+
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++lat_ts=<value>
+

Latitude of true scale. Defines the latitude where scale is not distorted. +Takes precedence over +k_0 if both options are used together.

+

Defaults to 0.0.

+
+ +
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++lon_0=<value>
+

Longitude of projection center.

+

Defaults to 0.0.

+
+ +
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++ellps=<value>
+

The name of a built-in ellipsoid definition.

+

See Ellipsoids for more information, or execute +proj -le for a list of built-in ellipsoid names.

+

Defaults to “GRS80”.

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+ +
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++R=<value>
+

Radius of the sphere, given in meters. If used in conjunction with ++ellps, +R takes precedence.

+

See Ellipsoid size parameters for more information.

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+ +
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++k_0=<value>
+

Scale factor. Determines scale factor used in the projection.

+

Defaults to 1.0.

+
+ +
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++x_0=<value>
+

False easting.

+

Defaults to 0.0.

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+ +
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++y_0=<value>
+

False northing.

+

Defaults to 0.0.

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+ +
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Note

+

lat_ts and k_0 are mutually exclusive. If lat_ts +is specified, it is equivalent to setting k_0 to +\(\frac{\cos \phi_{ts}}{\sqrt{1 - e^2 \sin^2 \phi_{ts}}}\)

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Further reading

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    +

  1. Wikipedia: Lambert cylindrical equal-area

    2. +

  2. Wikipedia: Gall-Peters

    3. +

  3. Wikipedia: Behrmann

    4. +
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