Interrupted

Classification	Interrupted meta-projection
Available forms	Forward and inverse, spherical and ellipsoidal
Defined area	Global
Alias	interrupted
Domain	2D
Input type	Geodetic coordinates
Output type	Projected coordinates

Meta-projection to create interrupted maps using different base projections. The supported projections are Cassini (Cassini-Soldner), Polyconic (American), Sinusoidal (Sanson-Flamsteed) and Transverse Mercator. The world is divided in gores tangent at the equator. [Huck2024]

Parameters

Note

All parameters are optional for the Interrupted projection except base.

+base=<value>: Base projection. It can be one of cass, poly, sinu or tmerc. Note that some projections may not behave correctly with too wide gores.

+gores=<value>

+gores can be a number or a list of comma separated values. When it is a single number, it is the number of equal gores. When it is a list, they are the relative sizes of the gores (v.g. 1,2,1).

Defaults to 3.

+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.

+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".

+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.