azimuthal mounting

a telescope mounting having vertical and horizontal axes of rotation which allow the telescope to turn in azimuth and elevation in order to be set at the required point of the celestial sphere. To track a star which moves according to observable diurnal motion of the celestial sphere, it is necessary to rotate the telescope simultaneously about both axes at varying speeds. Azimuthal mounting is used in large-scale radiotelescopes. It was first used in telescopy in the USSR for a large 6–meter reflector.