Scholarlink

<p>Signal path variation (SPV) in radio telescopes is a critical factor affecting observational accuracy, with structural deformation-induced path changes representing a primary error source. In Very Long Baseline Interferometry (VLBI) observations using large telescopes, such deformations introduce signal delays that compromise measurement precision, especially in high-accuracy applications like geodesy and spacecraft tracking. This study systematically investigates signal path variation patterns induced by structural deformations through theoretical analysis and experimental validation, focusing on four key mechanisms: gravitational deformation of main/sub-reflectors, thermal expansion/contraction of the main reflector, off-axis structural configurations, and antenna pointing errors. In the present paper, we analyse these mechanisms in the case of the Tianma 65-m radio telescope (TMRT) and of one prototype Square Kilometre Array (SKA) antenna. We determine that Z-direction displacement of the sub-reflector influences the SPV at a rate of 1.62&#xa0;mm/mm, with an uncertainty of 0.012&#xa0;mm. Elevation changes from 45° to 55° induce an SPV of 6.1&#xa0;mm. A temperature variation of 20&#xa0;°C leads to a 1.3&#xa0;mm shift of the antenna reference point, with an associated uncertainty of 0.4&#xa0;mm. For an off-axis structural antenna, an elevation deviation of 1 arcminute results in 0.4&#xa0;mm of SPV, with uncertainty remaining below 8&#xa0;μm. Additionally, a time delay of 1.1&#xa0;ps occurs when the antenna pointing shifts away from the optimal position.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

An investigation into the correlation between signal path variation and structural deformation in large radio telescopes

  • 期刊论文

  • 发表日期：

    2026年7月8日

查看全文
  • Lingling Wang,
  • Jinqing Wang,
  • Linfeng Yu,
  • Yongchen Jiang,
  • Qinghui Liu

摘要

Signal path variation (SPV) in radio telescopes is a critical factor affecting observational accuracy, with structural deformation-induced path changes representing a primary error source. In Very Long Baseline Interferometry (VLBI) observations using large telescopes, such deformations introduce signal delays that compromise measurement precision, especially in high-accuracy applications like geodesy and spacecraft tracking. This study systematically investigates signal path variation patterns induced by structural deformations through theoretical analysis and experimental validation, focusing on four key mechanisms: gravitational deformation of main/sub-reflectors, thermal expansion/contraction of the main reflector, off-axis structural configurations, and antenna pointing errors. In the present paper, we analyse these mechanisms in the case of the Tianma 65-m radio telescope (TMRT) and of one prototype Square Kilometre Array (SKA) antenna. We determine that Z-direction displacement of the sub-reflector influences the SPV at a rate of 1.62 mm/mm, with an uncertainty of 0.012 mm. Elevation changes from 45° to 55° induce an SPV of 6.1 mm. A temperature variation of 20 °C leads to a 1.3 mm shift of the antenna reference point, with an associated uncertainty of 0.4 mm. For an off-axis structural antenna, an elevation deviation of 1 arcminute results in 0.4 mm of SPV, with uncertainty remaining below 8 μm. Additionally, a time delay of 1.1 ps occurs when the antenna pointing shifts away from the optimal position.