Eckert IV

Classification

Pseudocylindrical

Available forms

Forward and inverse, spherical projection

Defined area

Global

Alias

eck4

Domain

2D

Input type

Geodetic coordinates

Output type

Projected coordinates

Eckert IV

proj-string: +proj=eck4

\[x = \lambda(1+cos\phi) / \sqrt{ 2 + \pi }\]
\[y = 2 \phi / \sqrt { 2 + \pi }\]

Parameters

Note

All parameters are optional for the Eckert IV projection.

+lon_0=<value>

Longitude of projection center.

Defaults to 0.0.

Note

The default convention is to interpret this value as decimal degrees. To specify radians instead, follow the value with the "r" character.

Example: +lon_0=1.570796r

See Projection Units for more information.

+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.

+x_0=<value>

False easting.

Defaults to 0.0.

+y_0=<value>

False northing.

Defaults to 0.0.