Research on surface detection and characterization of 3.2 m splicing radio antenna based on laser tracker

Abstract This paper proposes a new surface fitting method based on double model comparison to solve the aspherical surface parameters, allowing for the simultaneous extraction of the surface deviation and the optimal surface fitting parameters for the radio antenna’s main reflector. This method employs the laser tracker to obtain the 3D coordinates of the points on the antenna surface, which can be expressed in terms of Zernike polynomials. Then compare the Zernike polynomial description with the ideal aspherical equation description to establish a discrepancy model in the optical design software. Finally, by optimizing this model, the optimal surface parameters can be obtained. The simulation results show that the method is suitable for high-precision fitting of aspherical surfaces with cone coefficient K in the range of [−4, 0.3], with the maximum deviation percentage of the radius of curvature at 0.036% and the cone coefficient at 0.14%. Experimental research is conducted on the 3.2 m sector sub-aperture spliced radio antenna; the fitted radius of curvature is 2012.3204 mm, the conic coefficient is −1.0476, and the Root Mean Square (RMS) is 0.6232 mm, confirming the adaptability of this method.