The Establishment of Pointing Model for the TM65 m Radio Telescope

The method to establish the pointing model of the 65-meter radio telescope of Shanghai Astronomical Observatory (TM65 m) is described. The single-point data are collected by means of “cross scan”, then, they are fitted with a model including both the Gaussian and nonlinear terms. It is also simulated and analyzed how the antenna beam is broadened in the scanning process because of the angular size of a source. And the orbit prediction of sources is used to improve the modelling efficiency. Finally, an eight-parameter pointing model is built after fitting all the collected single-point errors. It is verified that the model works well in the X band and other low-frequency bands, the pointing accuracy at the X band attains 12.36 arcsec.