Measurement of NSRT 26m Antenna Track Unevenness and Influence on Pointing Accuracy

The track of wheel on track antenna is the important foundation which carries the whole antenna weight; its precision directly influences the operation of the antenna in azimuth direction stability, causing the shafting error and finally influences the antenna pointing accuracy. This paper introduces the reconstructed Nanshan Radio Telescope (NSRT) 26m antenna track structure and track unevenness measurement, and establishes the mathematical model of antenna pointing error caused by the track unevenness of the antenna under different azimuth and elevation angle. The cross scanning method is used to measure the pointing data of multiple standard radio sources in corresponding positions, and the pointing error is obtained through Gauss fitting method. Through analysis, we can see that the pointing error caused by track unevenness is corrected, and the antenna pointing accuracy can be improved.