主反射面变形引起的天线指向误差修正方法  

Correction Method of Pointing Error Caused by Deformation of Main Reflector of Antenna

作　　者：梅庚君 项斌斌[2] 王娜[2] 王兆军[1] MEI Geng-jun;XIANG Bin-bin;WANG Na;WANG Zhao-jun(College of Physical Science and Technology,Xinjiang University,Urumqi 830046;Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011)

机构地区：[1]新疆大学物理科学与技术学院,乌鲁木齐830046 [2]中国科学院新疆天文台,乌鲁木齐830011

出　　处：《天文学报》2020年第6期25-36,共12页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11563008);中国科学院“西部之光”人才培养引进计划(2017-XBQNXZB-021);国家重点研发计划(2018YFA0404702);中国科学院天文台站设备更新及重大仪器设备运行专项经费支持项目资助。

摘　　要：射电天线指向精度通常要求小于主波束宽度的1/10,对于短厘米波段或毫米波段的大口径反射面天线,指向精度要求高达几个角秒,对于天线性能目标的实现是个巨大的挑战,因此对于大口径高频段的反射面天线来说指向问题成为天线性能实现的重要关注焦点.在众多影响天线指向精度的结构子系统因素中,对主反射面变形因素的研究很少.文章结合天线的结构特点建立了反射面空间坐标系统,并基于变形后主面点的空间坐标值,提出了3自由度下的非线性最小二乘吻合的方法去精准预测天线指向.最后利用空间几何关系严格推导出了服务于天线指向误差修正的俯仰和方位的精确调整量,从而构建了主面变形同指向误差之间的间接关系,这对大型射电天线指向精度的提升具有一定的指导意义.The pointing accuracy of radio telescope is usually less than one-tenth of the main beam width.For large-caliber antennas with the short centimeter-band or millimeter-wave band,the pointing accuracy must be as high as several arc seconds.Therefore,for large-diameter and high-frequency reflective antennas,the pointing problem has become an important focus of antenna performance.Among many structural subsystem factors that affect the antenna pointing accuracy,little research has been done on the deformation factor of the main reflecting surface.Based on the structural characteristics of the antenna,a spatial coordinate system of the reflecting surface is established in this paper.Based on the spatial coordinate values of the principal surface points after deformation,a non-linear least squares fit method with 3 degrees of freedom is proposed to accurately predict the antenna pointing.Finally,the spatial geometric relationship is used to strictly derive the precise adjustments of the pitch and azimuth for the correction of the pointing error of the antenna,and the indirect relationship between the deformation of the main surface and the pointing error is constructed.This has certain guiding significance for improving the pointing accuracy of large radio antennas.

关 键 词：反射面天线 主面变形 指向误差修正 方法:最佳吻合 

分 类 号：P111[天文地球—天文学]