The azimuthal angle used in this
app can be south based or north based (use settings to specify).
South based means it is the angle between the south
point and the perpendicular projection of the star down onto the horizon. The azimuthal angle for an astronomical object in the south
therefore is 0°, in the west 90° and in the east -90°. In the north the azimuthal angle is -180° approaching from the east and 180°
approaching from the west.
North based means it is the angle between the north
point and the perpendicular projection of the star down onto the horizon. The azimuthal angle for an astronomical object in the south
therefore is 180°, in the west 270° and in the east 90°. In the north the azimuthal angle is 0° approaching from the east and 360°
approaching from the west.