## 5 Discussion and Conclusions  
Although there have been numerous reports on free-space optical communication, demonstration systems for ground-based local area information transmission networks are still worth exploring. Unlike space-based optical communication, ground atmospheric environments require faster network setup capabilities and the ability to cope with more complex atmospheric conditions. Therefore, to effectively address the rapid acquisition of ultra-long-distance atmospheric laser links, we designed a high-precision initial pointing technique for the laser terminal. By observing any star and correcting the optical axis pointing errors of the optical communication terminal, the initial pointing can be completed rapidly, and scanning acquisition can be performed in a short amount of time. This technique enables the fast deployment of ground-based local optical communication networks and demonstrates ultra-100 Gbps high-speed optical communication in weak turbulence windows.  
In conclusion, our research experimentally demonstrated the rapid acquisition and ultra-high-speed optical communication of ground-based ultra-long-distance atmospheric optical communication links. The high-precision laser terminal initial pointing method we proposed effectively reduces the scanning uncertainty region, and the coarse beacon scan enables rapid scanning acquisition. Multiple experimental results show that dual-end link scanning acquisition can be achieved within an uncertainty range of \(\pm\)0.1\({}^{\circ}\), which represents a breakthrough for ground-based atmospheric optical communication systems. In the future, this research will continue, and we will further investigate high-precision light spot position extraction techniques under turbulence effects, to enable long-term stable tracking of moving platform atmospheric optical communication links.  
Conceptualization, [PERSON] and J.H.; methodology, [PERSON]; software, [PERSON]; validation, [PERSON] and X.M.; formal analysis, [PERSON]; investigation, [PERSON]; resources, [PERSON]; data curation, [PERSON]; writing--original draft preparation, [PERSON]; writing--review and editing, [PERSON]; visualization, [PERSON]; supervision, [PERSON]; project administration, [PERSON]; funding acquisition, [PERSON] All authors have read and agreed to the published version of the manuscript.  
This research was funded by Supported by the National Natural Science Foundation of China, grant number 60171009.  
Not applicable.  
Figure 7: Statistical results of coupled laser power at the scanning terminal.  
**Data Availability Statement:** The data presented in this study are available upon reasonable request from the corresponding author. The data are not publicly accessible due to confidentiality agreements with collaborating institutions and the inclusion of proprietary technical specifications related to the experimental optical communication system.  
**Acknowledgments:** The authors express sincere thanks for the experiments provided by the Photoelectric Tracking and Measurement Technology Laboratory, Xi'an Institute of Optics and Precision Mechanics, CAS.  
**Conflicts of Interest:** The authors declare no conflicts of interest.