Effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope

作     者：Shan-Xiang Wei De-Qing Kong Qi-Ming Wang Shan-Xiang Wei;De-Qing Kong;Qi-Ming Wang

作者机构：Key Laboratory of Lunar and Deep Space ExplorationNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of FASTNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2021年第21卷第6期

页      面：253-262页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 070401[理学-天体物理] 0704[理学-天文学] 0825[工学-航空宇航科学与技术] 

基　　金：funded by the Astronomical Joint Fund of National Natural Science Foundation of China and Chinese Academy of Sciences(U1831114) the National Natural Science Foundation of China(11673040 and 11803053)。 

主　　题：telescopes finite element analysis thermal behavior pointing accuracy 

摘      要：The alidade’s non-uniform temperature field of a large radio telescope is very obvious under solar radiation.Estimating a radio telescope’s pointing errors,caused by the alidade deformation under solar radiation,is significant to improve the telescope’s pointing accuracy.To study the effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope,a temperature experiment is first carried out in a 70-m radio telescope on a sunny day.According to the measured results,the temperature distribution rule of the alidade is summarized initially.In addition,the alidade’s temperature field is calculated by finite element thermal analysis.The simulated results are proved to be in good agreement with the experimental results.Finally,the alidade deformation under solar radiation is computed by finite element thermalstructure coupling analysis.The telescope’s pointing errors caused by alidade deformation are estimated via the alidade’s node displacements.The final results show that the effect of alidade thermal behavior on the telescope’s elevation pointing errorsΔε2+Δεr is much more than the effect on the telescope’s crosselevation pointing errorsΔε1.The maximum ofΔε2+Δεr is more than 45″,while the maximum ofΔε1 is less than 6″.This study can provide valuable references for improving the pointing accuracy of large radio telescopes.