azimutale

Azimutale is the term used in cartography, astronomy, and navigation to describe azimuthal concepts or projections, where directions or points are related to a central point and projected onto a plane. In this sense, azimutale encompasses both angular measurements on the sphere and planar map representations derived from a central reference point.

In cartography, azimuthal projections map points from a sphere onto a plane with the center of projection at a chosen point on the sphere. The plane can be tangent to the sphere at the center or intersect it along a circle (secant). These projections are often used for regional maps or radio and radar applications because distances and directions radiating from the center can be interpreted more directly. Common variants include the orthographic, stereographic, gnomonic, and Lambert azimuthal equal-area projections, each with different properties regarding angle preservation, area, or distance.

In astronomy and navigation, azimutale concepts appear as azimuth and elevation (or altitude) angles that describe the direction to a celestial object or a target relative to an observer. Azimuth is the compass-like angle around the horizon, while elevation measures the angle above the horizon. This framework underpins telescope pointing, radio dish alignment, and sighting systems, and is often contrasted with celestial coordinate systems such as equatorial coordinates (right ascension and declination).

The term is sometimes used interchangeably with azimuthal, though precise usage distinguishes between azimuthal projections (the mapping method) and azimuth/elevation coordinates (the directional system). Overall, azimutale denotes a family of concepts centered on a point that define directions and positions on or from a plane.