Airocean

Added in version 9.6.0.

The Airocean map projection is a icosahedron polyhedral projection that intends to lay down continental landmasses into a contiguous map with minimal scale and angular distortion while preserving land surfaces from (most) interruptions. In comparison to the Snyder's Icosahedral Equal Area, this projection relies on a specific way to orient and cut the icosahedron so that most interruptions lie within the ocean. The projection was first invented by Buckminster Fuller in 1943 using a cuboctahedron as basis. The idea to use an icosahedron came later in 1954, and it wasn't until 1978 that the projection was formally mathematically defined [Gray1995].

Classification	Polyhedral, equal area
Available forms	Forward and inverse, spherical and ellipsoidal
Defined area	Global
Alias	airocean
Domain	2D
Input type	Geodetic coordinates
Output type	Projected coordinates

Note

The airocean map of the whole globe has an extent of approximately \([0, 0, 17404000, 36844000]\) in meters. Although the airocean map has no true up or down, the choice was made to lay it out vertically, from Antarctica to Australia.

Parameters

Note

All parameters are optional for the projection.

+orient=<string>

Can be set to either vertical or horizontal.

Defaults to vertical

+lon_0=<value>

Central meridian/longitude of natural origin, longitude of origin or longitude of false origin (naming and meaning depend on the projection method).

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, easting at false origin or easting at projection centre (naming and meaning depend on the projection method). Always in meters.

Defaults to 0.0.

+y_0=<value>

False northing, northing at false origin or northing at projection centre (naming and meaning depend on the projection method). Always in meters.

Defaults to 0.0.