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

Projection String

+proj=ortho
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Required Parameters

• None

Optional Parameters

• +alpha=<value>: Azimuth clockwise from north at the center of projection. Defaults to 0.0. (added in PROJ 9.5.0)
• +k_0=<value>: Scale factor. Determines scale factor used in the projection. Defaults to 1.0. (added in PROJ 9.5.0)
• +lon_0=<value>
• +lat_0=<value>
• +ellps=<value>
• +R=<value>
• +x_0=<value>
• +y_0=<value>

Notes

• Before PROJ 7.2, only the spherical formulation was implemented. To replicate PROJ < 7.2 results with newer versions, force the ellipsoid to a sphere using +f=0.
• This projection method corresponds to EPSG:9840 (or EPSG:1130 with k_0 or alpha).