Astronomical Coordinates at the Parkes Radio Telescope

Abstract The Parkes radio telescope has been fitted with a new control system. Part of this system is a computer for transforming position requests into commands to the telescope drive. The high computing power coupled with a new control for the master control unit has allowed modes of telescope control not previously available. These new capabilities include scanning the telescope in any astronomical coordinate system, the definition and use of beams offset in azimuth and elevation from the telescope’s optical axis and the definition of arbitrary coordinate frames which may move with respect to standard reference frames. The new control system fully supports the new standard epoch of J2000.0 and uses the newly adopted constants for Earth axis precession and nutation.