Angle of Position.In great circle sailing, is angle that great circle track makes with meridian at any given point. In celestial triangle, is angle at the heavenly body which is subtended by the colatitude.
Angle of the Vertical.Difference between the perpendicular at a place and the extended radius of Earth passing through the place. Arises through Earth being an oblate spheroid. It is, therefore, the difference between True and Reduced latitudes of the place. Value is maximum in Lat. 45° (about) and is minimum at Poles.