XAO OpenIR  > 研究生学位论文
射电望远镜参考点测量方法的研究
Alternative TitleResearch on Measurement Method of Radio Telescope Reference Point
刘耘
Subtype硕士
Thesis Advisor陈卯蒸
2019
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Name理学硕士
Degree Discipline天文技术与方法
Keyword射电望远镜 参考点 Radio telescope 轴线偏差 reference point GNSS axis offset 仿真分析 GNSS simulation analysis
Abstract精确测量射电望远镜参考点坐标和轴线偏差,对建立天线指向模型和局部连接参数、提高测站坐标精度等具有重要意义。常规静态归心测量方法需要在天线周围布设局域控制网,涉及本地坐标系和地心坐标系之间的转换,测量过程较为繁琐。随机动态测量方法中,射电望远镜的方位角和俯仰角作为已知量进行解算,对还未建立指向模型的新建射电望远镜并不适用。为了完成新建射电望远镜参考点初始参考值的快速测定,根据望远镜的旋转模型,结合常规静态归心测量方法和随机动态方法,提出一种利用GNSS代替测量靶标实现望远镜参考点测量的方法。在两种不同的射电望远镜旋转方式下采集数据。单轴旋转方式下GNSS天线的运动轨迹是空间圆,对绕方位轴和俯仰轴旋转采集的数据分别进行空间圆拟合确定方位轴和俯仰轴的位置和定向。随机旋转方式下GNSS天线的运动轨迹是空间球体上带状区域内的点,对采集的数据进行球拟合得到的球心坐标即参考点坐标。通过模拟数据验证了该方法的有效性,并仿真分析了GNSS定位精度和采集数据个数对天线参考点和轴线偏差解算精度的影响,为射电望远镜参考点的实测提供了理论指导。该方法的优势是不用建立测量基墩,在数据拟合时不涉及本地坐标和地心坐标之间的转换,不依赖于天线的指向模型。空间圆的拟合精度会决定天线参数的解算精度,针对空间圆拟合,提出了一种基于遗传算法的拟合方法,并利用模拟数据和实例数据验证了方法的准确性和可靠性。单轴旋转方式下绕俯仰轴旋转采集的数据点分布在空间圆上小于1/4的圆弧段上,有时会存在拟合不稳定的情况,因此选用了易于实现且稳定性更好的空间圆拟合方法。
Other AbstractAccurate measurement of the reference point coordinates and axis offset of the radio telescope is of great significance for establishing the antenna pointing model and local tie vector, and improving the coordinate accuracy of the station. The common local survey method needs to arrange a local control network around the antenna, which involves the conversion between the local coordinate system and the geocentric coordinate system, and the measurement process is complicated. In the parameterized modeling of the antenna rotation survey method, the azimuth and elevation angles of the radio telescope are solved as lknown quantities, so this method is not applicable to the newly-built radio telescopes that have not yet established a pointing model. In order to quickly determine the initial reference value of the reference point coordinates of the newly-built radio telescope, according to the rotation model of the telescope, combined with the common local survey method and the parameterized modeling of the antenna rotation survey method,a method of using GNSS instead of the measurement target to realize the telescope reference point measurement is proposed. The data is collected in two different rotation modes of the radio telescope. The trace of the GNSS antenna in the single-axis rotation mode is a space circle, and spatially rounded fitting is performed on the data acquired around the azimuth axis and the elevation axis to determine theposition and orientation of the azimuth axis and the elevation axis. The trace of the GNSS antenna in the random rotation mode is the point in the strip region on the space sphere, and the spherical center coordinates obtained by the sphere fitting of the collected data are the reference point coordinates. The effectiveness of the proposedmethod is verified by the simulation data. The influence of GNSS positioning accuracy and the number of acquired data points on the accuracy of antenna reference point and axis offset calculation is analyzed. It provides theoretical guidance for the actual measurement of the radio telescope reference point. The advantage of this method is that it does not need to establish a measurement base pier, and does not involve the conversion between local coordinates and geocentric coordinates when the data is fitted, and does not depend on the pointing model of the antenna. The fitting accuracy of the space circle determines the accuracy of the antenna parameters. For the spatial circle fitting,a fitting method based on genetic algorithm is proposed. The accuracy and reliability of the method are verified by simulation data and example data. In the single-axis rotation mode, the data points collected by rotating around the elevation axis are distributed on the circular arc segment less than 1/4 of the spatial circle, and sometimes the fitting is not stable. Therefore,a space circle fitting method that is easy to be implemented and has better stability is selected.
Pages59
Language中文
Document Type学位论文
Identifierhttp://ir.xao.ac.cn/handle/45760611-7/2711
Collection研究生学位论文
Affiliation中国科学院新疆天文台
First Author AffilicationXinjiang Astronomical Observatory, Chinese Academy of Sciences
Recommended Citation
GB/T 7714
刘耘. 射电望远镜参考点测量方法的研究[D]. 北京. 中国科学院大学,2019.
Files in This Item:
File Name/Size DocType Version Access License
刘耘-硕士学位论文最终版.pdf(3050KB)学位论文 暂不开放CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[刘耘]'s Articles
Baidu academic
Similar articles in Baidu academic
[刘耘]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[刘耘]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.