Azimute

Azimute is the angular measurement used to express direction in a horizontal plane. In many languages, including Portuguese where the term is common, azimute corresponds to the English azimuth. It denotes the clockwise angle from a reference direction, typically true north, to the projection of a line of interest onto the horizontal plane.

Conventionally, azimute is measured in degrees, but radians are also used in some technical contexts. A full circle is 360 degrees, with 0 degrees corresponding to north, 90 degrees to the east, 180 to the south, and 270 to the west. Azimute values can be given in the range 0–360 degrees or converted to the -180 to 180 degree range depending on the application. Three related variants are true (geodetic) azimute, magnetic azimute (relative to magnetic north), and grid azimute (relative to map grid north).

Azimute is a component of horizontal coordinate systems, the other being altitude or elevation. It is widely used in navigation, surveying, cartography, and astronomy. Instruments such as compasses, theodolites, total stations, and GNSS-based systems measure or compute azimutes to locate objects, plan routes, or map features. In astronomy, azimute is used with altitude to specify the position of celestial objects as seen from a given observer’s location.

Conversion and calculation methods vary with context, but a common relation is that the azimute can be derived from a north-based components pair (N, E) as arctan2(E, N), yielding the angle from north toward east.