大口径射电望远镜热致结构误差实时评估与补偿

With the development of radio telescopes to high frequency and large aperture, the loss of high frequency performance caused by thermal gradients cannot be neglected. Limited by the current measurement methods and the complexity of the antenna thermal environment, there is currently no effective way to compensate for such performance loss in real time, which greatly limits the effective working time of the antenna in the high frequency band. This project carries out research on the real-time evaluation and compensation for thermal-induced structural errors. Through the establishment of a structural thermal sensitive points search method, sensors will be optimally laid out, and the fiber grating temperature measurement technology will be applied to achieve high-precision measurement of the antenna temperature field. To realize the real-time evaluation and compensation for the thermal-induced structure error, the coupling model between the temperature field and the antenna structure error will be established based on the structural-thermal deformation mapping mechanism. A semi-physical simulation platform will be designed to test and verify the temperature measurement method and thermal-structure coupling model, and the evaluation and compensation method will be corrected based on the real-time measurement of the 26-meter NanShan Radio Telescope (NSRT). This research will finally provide a reference to the thermal-induced structural error compensation for large-aperture antennas, and support the construction and performance optimization for 110-meter aperture QiTai radio Telescope (QTT).

随着射电望远镜向高频段、大口径方向发展，温度梯度引起的天线高频观测性能损失已不容忽视。受限于当前测量手段以及天线热环境的复杂性，当前尚无有效方法可实时补偿此类性能损失，极大地限制了天线在高频段的有效工作时间。本项目开展天线热致结构误差实时评估和补偿研究，通过建立结构热敏感点搜寻方法进行传感器优化布局，并应用光纤光栅测温技术，实现天线温度场的高精度测量。基于热-结构变形实时映射机理建立温度场与天线结构误差之间的耦合模型，实现天线热致结构误差的实时评估和补偿。设计半实物仿真平台用于实验和校正温度测量方法与热-结构耦合模型，基于南山26米射电望远镜(NSRT)实时测量修正热致结构误差评估方法，最终为大口径天线热致结构误差补偿提供参考，为奇台110米射电望远镜（QTT）建设和性能优化提供支持。

随着射电望远镜向高频段、大口径方向发展，温度梯度引起的天线高频观测性能损失已不容忽视。受限于当前测量手段以及天线热环境的复杂性，当前尚无有效方法可实时补偿此类性能损失，极大地限制了天线在高频段的有效工作时间。本项目开展天线热致结构误差实时评估和补偿研究。首先实现了一种射电望远镜天线的高精度测温方法，基于结构热敏刚度特性分析确定传感器优化布局方法，应用光纤光栅测温技术实现无电磁干扰问题的接触式测温。通过对分析工况进行归类和简化，建立了温度场分布特征数据库，实现了利用少量温度测量数据对复杂结构温度分布的快速重构。通过计算热-结构影响矩阵，实现了结构温度场至热变形的实时映射，并进一步建立了温度场、结构场至天线结构误差之间的矩阵式计算模型，提出了一种射电望远镜天线热致结构误差的实时评估方法。在新疆天文台南山观测站搭建了一套半实物仿真平台，利用其对温度场测量方法和结构误差评估方法进行了实测。在实际运行的南山25米射电望远镜(NSRT)上布设了96枚温度传感器，对实时测量修正热致结构误差评估方法进行了进一步验证。实验测量结果显示，本项目提出的温度场高精度测量与重构方法、结构误差评估方法具有较高的评估精度。本研究所提出的方法能够准确地评估天线由太阳辐照产生的结构误差，故具备进一步工程化，未来服务于正在运行或正在建设的大口径射电望远镜的潜力。