轨道不平度对天线指向的影响分析与修正

发布时间：2018-05-20 07:57

本文选题：望远镜 + 天文仪器　；参考：《天文学报》2017年04期

【摘要】：基于天线轨道不平度对望远镜指向的影响机理,测量并分析采用整体焊接轨道技术后的乌鲁木齐南山26 m射电望远镜(NanShan Radio Telescope,NSRT)天线轨道误差的分布情况及对指向的影响,从而对指向模型进行修正.采用移动最小二乘法(Moving Least-Squares,MLS)将测得的天线轨道高度差拟合成一个闭合的轨道高度分布曲线,确定因轨道不平度影响的天线方位轴偏差,对比实测天线座架变形的方位轴偏差,发现二者具有较强的相关性.考虑到天线座架重力变形的偏差包含南北向和东西向偏差,建立新的指向偏差模型进行校正.最后通过对已知校准射电源进行扫描测量,将指向偏差数据进行拟合.结果表明:新建的指向修正模型能够抑制已知指向模型偏差中的正弦分量,从而说明所建模型很好地反映了天线的指向偏差并对偏差具有一定修正作用.
[Abstract]:Based on the influence mechanism of antenna orbit irregularity on telescope pointing, the distribution of antenna orbit error of Shan Shan Radio TelescopeNSRT, a 26 m radio telescope in Nanshan, Urumqi, and its effect on pointing are measured and analyzed. In order to modify the pointing model. By using moving least-squares method (MLS), the measured orbit height difference is fitted into a closed orbit height distribution curve, and the azimuth axis deviation of antenna due to track irregularity is determined, and the azimuth axis deviation of antenna frame deformation is compared. It was found that there was a strong correlation between them. Taking into account that the deviation of gravity deformation of the antenna seat includes the deviations from the north to the south and the east to the west, a new directional deviation model is established to correct the deviation. Finally, by scanning and measuring the known calibrated radio source, the pointing deviation data is fitted. The results show that the new directional correction model can suppress the sinusoidal component of the known deviation of the pointing model, which shows that the proposed model can well reflect the pointing deviation of the antenna and has a certain correction effect on the deviation.
【作者单位】：中国科学院新疆天文台;中国科学院射电天文重点实验室;中国科学院大学;西安电子科技大学机电工程学院;电子装备结构设计教育部重点实验室;
【基金】：国家重点基础研究发展计划(2015CB857100) 国家自然科学基金项目(11403089、51490660) 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(2014、2015)资助
【分类号】：P111.44

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