A Study on the Measurements and Improvements of Pointing Accuracy of Jiamusi 66m Radio Telescope

Pointing accuracy is one of the most important characteristics for a large radio telescope; it is very fundamental for telescope running. To ensure good performance for measuring the flux density of a radio source, pointing accuracy must be kept within 10% of telescope beam size. In this paper we present results of large measurements of telescope points for Jiamusi 66m radio telescope, and show the basic-parameter model and the fitting residuals of pointing data. We find that even after the correction of a new best-fitting basic-parameter model, the pointing uncertainty data still have a systematic variations of concentration along with the azimuth and elevation, which we believe is caused by the high order variations of the angle between the azimuth axis and elevation axis as well as the gravity deformation. We improve the basic-parameter model for the pointing corrections, and we get much improved pointing accuracy for Jiamusi 66m radio telescope from 45" to less than 20".