azimuth

(1) A surveying observation used to measure the angle formed by a horizontal baseline and true or geodetic north (or south). When applied to GNSS observations, it refers to a normal section azimuth.

(2) The horizontal angular measurement from a reference direction, usually the northern point of the horizon, eastward to the point where a vertical circle through an astronomical object (for example, a satellite) intersects the horizon.

Azimuth is often confused with bearing. Azimuth is measured clockwise from 0 to 360 degrees (0 to 400 gons) from true or geodetic north (or south). Bearing is the direction of a line stated specifically or generally and is referenced to a meridian or a baseline. When stated specifically, a bearing is an angle within a quadrant (for example, the NE quadrant, SW quadrant) and is never greater than 90 degrees.