Comparison of Wavefront Sensing Methods for Solar Ground-Layer Adaptive Optics: Multi-Direction Averaging and Wide-Field Correlation

Solar ground-layer adaptive optics (GLAO) is widely recognized as a key technology for achieving high-resolution, wide-field imaging in ground-based solar telescopes. However, the accuracy differences among various wavefront sensing methods in solar GLAO remain unclear. In this study, Monte Carlo simulations and indoor GLAO experiments were conducted to perform, for the first time, a comparative analysis of two representative wavefront sensing methods: multi-direction averaging (MD-A) and wide-field correlation (WF-C). The results demonstrate that WF-C consistently achieves higher detection accuracy than MD-A, although the differences between the two methods are small. With an increasing field of view (FoV), the detection accuracy of MD-A improves but remains lower than that of WF-C. In terms of correction performance, significant improvements in central FoV imaging were achieved using WF-C within narrow-to-moderate FoVs, whereas in wide and ultra-wide FoVs, MD-A produced more uniform image quality enhancements. Using the 1 m New Vacuum Solar Telescope (NVST) GLAO system as an example, MD-A is better suited to wide and future ultra-wide field imaging (over 80″), whereas WF-C is more appropriate for high-precision wavefront sensing within narrow to moderate fields (20″–60″). These findings provide both theoretical guidance and practical insights for the optimization of GLAO systems and wavefront sensing strategies in 1-meter-class wide-field solar telescopes.