Azimuth

Azimuth is the bearing of a celestial body, the horizontal angle at the observer measured clockwise from true north (000 to 360 degrees) to the vertical circle through the body. In sight reduction the azimuth Zn is computed alongside the altitude Hc; the intercept is then plotted toward or away from the body along that direction, and the line of position is drawn perpendicular to it. Azimuth angle Z, measured from the elevated pole, converts to Zn by rules of LHA and hemisphere. A computed azimuth compared against an observed compass bearing of the Sun or a star yields the compass error.