## 1 Introduction  
The radio telescope is essential for receiving radio waves from celestial bodies. Its most apparent feature is its large dual-reflector antenna structure [1]. Environmental factors such as gravity, temperature, wind, and inertial loads [2] can deform the antenna structure, resulting in a deviation from the required surface shape. This deformation reduces the antenna gain, making the radio telescope unable to meet the accuracy requirements of high-frequency operation [3, 4]. The conformal design of the antenna can reduce this deformation to a certain extent, but it cannot eliminate it [5]. Finite element analysis technology [6] can analyze the mechanical properties of the antenna structure. It is essential to establish an FE model that meets the accuracy requirements and can accurately reflect the structure's mechanical properties for evaluating the structure's mechanical properties [7]. For antenna structures, uncertainties such as manufacturing errors, assembly defects, and model simplification will cause errors between the FE model based on design data and the calculation results of the actual structure [8, 9], and these will affect the evaluation of antenna performance and active structural compensation [10]. A technique for updating the FE model [11] can effectively address this issue. Current methods for updating the FE model are mainly matrix and parametric parameter methods. The matrix method mainly updates the FE model by updating the critical matrices of the FE model, such as stiffness, mass, and damping matrices [12]. The parameter method mainly updates the physical parameters, such as geometric dimensions and material properties in the model, to align the FE model calculation results closer to the measured response [13]. Compared to the matrix method, the parametric method holds greater physical significance and is more readily applicable in engineering and subsequent analysis. Therefore, the parameter method is widely used in engineering [14]. However, when updating FE models using traditional parametric methods, the numerous model parameters make the computational cost of identifying key parameters and optimizing the model too high. The development of computer technology has effectively mitigated these problems. However, for problems with large, complex structures, thousands of simulations are often required to construct a suitable solution due to the high fidelity requirements of their FE models [15]. Surrogate models are usually introduced in engineering calculations to approximate the structural behavior and reduce the computational burden, thus effectively reducing the computational complexity in finite element analysis and making analysis and design more efficient [16]. Currently, there are relatively few studies on updating FE models for ground antenna main reflector deformation problems. In Reference [17], the FE model of a 64 m aperture radio telescope antenna was updated by updating the load vector in the stiffness matrix based on the deformation data of the antenna's primary reflector surface obtained by photogrammetry. This method is classified as a matrix method, and it can make the results calculated by the FE model of the antenna approximate the actual measured results. However, the physical meaning of the model updating needs to be improved. Reference [18] proposed a method of updating the antenna FE model based on a hypothetical experiment. It updates the material property parameters in the FE model of the antenna of a 1.2 m radio telescope and reduces the deformation error of the main reflecting surface of the antenna's FE model under temperature and gravity loads. This method is a parametric method with a clear physical meaning. However, for FE model updating of a large-aperture radio telescope antenna composed of complex structures, it will take much time to use this method.