## 5 Conclusions  
Without additional hardware, a real-time turbulence profile measurement system was deployed on NVST for the measurement of atmospheric turbulence intensity and distribution. The measurement system acquired wavefront sensor slope data and voltage data from the RTC of the GLAO system to recover the turbulence wavefront information. Multiple sub-apertures and guide regions were employed to measure turbulence intensity distribution with DIMM and SLODAR methods. The simulation results show that for the conventional DIMM method with a pair of sub-apertures and one guide star, the value of measured \(r_{0}\) is from 8.0 cm to 12.5 cm corresponding to the input of 10 cm. Two conventional measurement algorithms, SLODAR and S-DIMM+, were compared with the same parameters in a simulation in order to cross-verify the correctness of our calculations based on the data process of pseudo-open loop data and multiple sub-aperture pairs. The results show that the measurement accuracy of the SLODAR method (93%) is slightly higher than S-DIMM+ (87%). The SLODAR method may cause a decrease in accuracy in detecting high layers, while a decrease in the accuracy of S-DIMM+ occurred in the middle layer's measurement. The results with closed-loop and open-loop data did not show a difference in measurement accuracy. This means that the measurement system could operate smoothly during the normal closed-loop operation of the GLAO system. Figure 11: Statistical results of two methods. \begin{table}
\begin{tabular}{c c c c} \hline _/\%_ & **0–2000** & **2000–10,000** & **>10,000** \\ \hline SLODAR & 86.0 & 12.3 & 1.7 \\ S-DIMM+ & 78.4 & 19.3 & 2.3 \\ \hline \end{tabular}
\end{table} 
Table 3: The proportion of turbulence intensity at different heights. The system was tested indoors with the heat-air turbulence simulator after being deployed on the NVST. Then, we observed and measured the atmospheric turbulence profile on 28 May 2023. The results from open-loop and closed-loop measurements were relatively consistent. Off-line measurement based on the S-DIMM+ method was carried out for the comparison. The corresponding results were very similar to the real-time measurement results of the measurement system with the SLODAR method. Statistical analysis of these results revealed that approximately 80% of the turbulence was located at a height below 2000 m; only a few appeared at the upper height. The results based on open-loop data and close-loop data also showed consistency, but there were differences in the detection of strong and weak turbulence. Since these differences were not present in the simulation, noise might be the main cause of this difference. The closed loop of the adaptive optical system might affect the wavefront detection accuracy of MD-WFS. In addition, due to the optimization method, the detection accuracy for weak turbulence might be relatively low, especially when noise exists simultaneously. This measurement system should be the first real-time atmospheric turbulence measurement system that does not require hardware costs and works simultaneously with the GLAO system. It could be combined with the GLAO system and MCAO system to facilitate subsequent processing and application. However, this measurement system relied entirely on data from the GLAO system. So, it could only measure when the GLAO system was running, which puts higher requirements on the observation time. In addition, in the case of very strong turbulence, MD-WFS wavefront detection might be quite difficult. In this case, the measurement of atmospheric turbulence parameters might be invalid. Methodology, writing--review and editing: [PERSON]. ([PERSON]), [PERSON] and C.R. ; software: [PERSON]. ([PERSON]) and H.B. ; validation: [PERSON]. ([PERSON]), [PERSON], [PERSON] ([PERSON]), [PERSON], D.T. and C.W. ; writing--original draft preparation, visualization: [PERSON]. ([PERSON]); supervision, project administration, funding acquisition: [PERSON] and C.R. All authors have read and agreed to the published version of the manuscript.