Dynamic Optical Alignment Method for AIMS
Abstract
The Accurate Infrared Solar Magnetic Field Measurement System (
Aims
is a mid-infrared telescope designed for high-precision solar magnetic field observations. Due to its open-truss structure and off-axis optical configuration, the system is prone to gravityinduced misalignment between the primary and secondary mirrors, which degrades image quality. To address this issue, this paper proposes a dynamic image quality alignment method based on a Shack–Hartmann wavefront sensor and a hexapod-mounted secondary mirror. The method uses nighttime point-source observations to measure system wavefront errors at different elevation angles and establishes an elevation-dependent lookup table through iterative optimization. Numerical simulations incorporating atmospheric turbulence and detector characteristics show that multi-frame averaging significantly improves wavefront reconstruction accuracy and stability. Experimental results demonstrate that the proposed method reduces the system wavefront root mean square (RMS) to within 0.16 λ at 630 nm at different elevation angles, thereby significantly improving imaging performance. During daytime observations, pre-calibrated correction parameters combined with temperature compensation enable dynamic image quality alignment. This approach enhances the operational stability and imaging capability of
Aims
and provides a practical solution for image quality correction in large ground-based telescopes.