Aimed at the alidade of TM65m antenna, the distributions of temperature field and effects of thermal deformations on pointing accuracy were analyzed based on thermometers and inclinometer. The alidade temperature and cross-elevation tilt were recorded for one year when the antenna was at different azimuth and elevation angles. And, the emphasis is on studying the data of sunny days in summer and winter during the antenna parked its home position (azimuth angle=155°, elevation angle=90°). The results show the maximum temperature difference between day and night is 14.6 °C in summer and is 27 °C in winter. In winter, the larger temperature difference, shorter sunshine time and later sunrise contribute to the temperature variation per unit time is larger. In addition, pointing offset was checked by scanning polestar for continuous 24 hours. From the results obtained so far, it seems that the elevation offset caused by the alidade temperature variation is more than 20 arcsec from 8:00 am to 10:00 am. The research results provide a base for the enhancement of pointing accuracy.

Date Published: 22 July 2016
PDF: 7 pages
Proc. SPIE 9912, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II, 99124J (22 July 2016); doi: 10.1117/12.2231263

Published in SPIE Proceedings Vol. 9912:
Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II
Ramón Navarro; James H. Burge, Editor(s)