# Real-Time State Evaluation System of Antenna Structures in Radio Telescopes Based on a Digital Twin
## 1 Introduction  
The radio telescope is the basic equipment for observing and studying radio waves from celestial bodies, and it is widely used in astronomy, radar, communication, and other fields [1]. With the rapid development of radio astronomy technology, the design, construction, and feeding technology of the antenna have been significantly upgraded, and the requirements for the working performance of the antenna are getting higher and higher. The radio telescope is gradually developing in the direction of large aperture, high gain, and high-frequency bands [2]. However, a radio telescope will be subjected to external loads such as wind and temperature, along with its self-weight, during operation, causing deformation of the antenna structure. This deformation will not only cause the antenna surface accuracy to deteriorate but will also reduce the antenna's pointing accuracy. Consequently,the reflective surface deformation and pointing error double superposition will ultimately significantly affect the antenna's receiving sensitivity and signal-focusing ability [3]. At the same time, as a high-precision radio astronomical observation platform, the radio telescope has a complex engineering structure, difficult operation and maintenance, a remote location, and a long cycle [4]. Although the current monitoring system of the radio telescope adopts a distributed control method and realizes remote monitoring of equipment, there are still some problems, such as low integration, insufficient intelligence, weak interaction, and poor visualization. As a new round of scientific and technological revolution and industrial transformation evolves rapidly, higher requirements have been put forward for the antenna monitoring system, which makes the condition monitoring and evaluation of modern radio telescopes develop in the direction of intelligence and digitization. In response to these challenges, many institutions and experts have invested significant effort into researching more intelligent and effective control methods. The Nanshan 26 m radio telescope, shown in Figure 1, focuses on pulsar observations, molecular spectral line studies, very long baseline interferometry (VLBI) [5], and deep space exploration. It employs a distributed management system based on the native GUI mode for monitoring, enabling the real-time oversight of certain equipment. [PERSON] et al. [6] have enhanced the efficiency of high-frequency signal processing in radio telescopes by implementing multi-dimensional signal processing and the real-time optimization of Field-Programmable Gate Array (FPGA) and digital very large-scale integration (VLSI) architectures. This has led to a substantial improvement in imaging accuracy and anti-interference performance. The Sardinian Radio Telescope in Italy has developed a set of primary reflector system control software based on the Python 2.7 language [7], which uses 1008 electromechanical actuators to dynamically adjust its active surface panels [8]. [PERSON] et al. [9] designed a comprehensive online monitoring system for the Shanghai Tianma radio telescope, which realized the monitoring and protection of lightning waveforms. Despite the achievements of these monitoring methods, there are still deficiencies in terms of globalization, digitization, visualization, and rapid two-way interaction. The emergence of digital twin (DT) technology provides a new idea for digital management and full lifecycle monitoring of radio telescopes. Based on the Internet of Things technology, DT uses digital methods to build a high-fidelity twin model for physical entities. Through data collection, fusion, and mapping, the twin model can reflect the attributes, behaviors, states, and performance of physical entities in real time and perform rapid simulation and prediction [10]. [PERSON] et al. [11] used DT technology to optimize the drilling process, and through simulation analysis, identified the critical impact of robot model joints on drilling operations.