Azimuthal projections

In an azimuthal projection, part of the earth is projected on a plane. The plane touches the earth sphere in one point (point of tangency, c); this point has the so-called central latitude and longitude. The projection rays can be a bundle, convergent in a point on the line through c, perpendicular to the tangent plane. The projection can also be secant, i.e. intersecting the sphere, instead of tangent.

In the projection, the azimuth or direction from the center of projection to any other point is shown correctly.

The mapmaker has to select the center of projection, i.e. a central meridian and central parallel:

• when the center point is located at a pole, we speak of a polar aspect;
• when the point is located at the equator, we speak of the equatorial aspect;
• when the point is located anywhere else, we speak of the oblique aspect.

See also: