Orthographic

The orthographic projection is a perspective azimuthal projection centered around a given latitude and longitude.

Classification

Azimuthal

Available forms

Forward and inverse, spherical and ellipsoidal

Defined area

Global, although only one hemisphere can be seen at a time

Alias

ortho

Domain

2D

Input type

Geodetic coordinates

Output type

Projected coordinates

Orthographic

proj-string: +proj=ortho

Note

Before PROJ 7.2, only the spherical formulation was implemented. If wanting to replicate PROJ < 7.2 results with newer versions, the ellipsoid must be forced to a sphere, for example by adding a +f=0 parameter.

This projection method corresponds to EPSG:9840.

Parameters

Note

All parameters for the projection are optional.

+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=1.5708r

See Projection Units for more information.

+lat_0=<value>

Latitude 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: +lat_0=1.5708r

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.

Defaults to 0.0.

+y_0=<value>

False northing.

Defaults to 0.0.