摘要
本文提出了一种通过扫描天线近场半球表面电场强度来获取天线面形分布的新方法,该方法无需测量相位、扫描面积小、可实现全姿态测量.研究将微分几何理论与几何光学方法相结合,推导出了球面近场幅值分布与表面变形间直接映射关系的解析形式-幅值变形方程,并基于有限差分法和傅里叶变换法对方程进行求解,使用几何光学数值仿真证明了幅值变形方程的准确性和测量方法的有效性.结合本文提出的扫描机构设计从扫描分辨率限制、探头定位误差和测量信噪比等角度分析验证了测量方案的可行性,并重点使用基于物理光学和物理绕射理论的数值仿真模拟了整体测量精度.此外引入奇异值分解去噪方法降低了低信噪比对测量精度的影响.
This paper proposed a new method for obtaining the antenna surface deformation by scanning the electric intensity of anear-field hemispherical surface. This method does not need to measure the aperture phase and can realize full attitudemeasurement with a small scanning area. This study developed a deformation-amplitude equation by combining thedifferential geometry theory and geometric optics method to establish a direct relation between surface deformation andamplitude distribution. The amplitude deformation equation can be solved using the finite difference method and fastFourier transform method. Numerical simulation results proved the accuracy of the amplitude deformation equation and theeffectiveness of the proposed measurement method. Furthermore, the singular value decomposition method was introducedto reduce the influence of low signal-to-noise ratio on the measurement accuracy.
作者
叶骞
王博阳
杨德金
孟国香
王娜
YE Qian;WANG BoYang;YANG DeJin;MENG GuoXiang;WANG Na(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2024年第1期50-64,共15页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家重点研发计划(编号:2021YFC2203501)
国家自然科学基金(编号:U1931137)资助项目。
关键词
射电望远镜
天线
几何光学
数学过程
radio telescopes
antennas
geometrical optics
mathematical procedures
