Simultaneous evaluation of turbulence profiles with RINGSS and LOLAS for ground-layer adaptive optics

Ground-layer atmospheric turbulence provides a significant contribution to overall turbulence and particularly impacts the design of ground-layer adaptive optics (GLAO) systems. To address the need for altitude-resolved turbulence quantification and evaluate the feasibility for the future Large Optical/Infrared Telescope site, we provide a preparatory step for monitoring at the Saishiteng Mountain observatory site by introducing the synergistic deployment of Ring-Image Next Generation Scintillation Sensor (RINGSS) and Low Layer Scintillation Detection and Ranging (LOLAS). RINGSS delivers moderate-altitude resolution (eight altitude bins) and full-atmosphere turbulence integration (0 to 16 km), whereas LOLAS achieves meter-scale resolution (0 to 250 m), obtaining the contribution and details of the ground layer. During a 2023 campaign at Xuyi Observation Station (118°27′48″E, 32°44′15″N, China), simultaneous measurements revealed that more than 70% of total turbulence resides within the ground layer (0 to 250 m), with over 50% of ground-layer turbulence further concentrated below 50 m. Cross-validation demonstrated agreement between instruments (Pearson correlation coefficient: Rxy=0.77 in 0 to 250 m seeing), though LOLAS systematically underestimates turbulence strength under poor seeing (ϵ0>3.0″). This integrated approach provides actionable metrics for optimizing the GLAO mirror conjugation strategy and facility elevation of the Large Optical/Infrared Telescope.