**6. Conclusions**

In this paper, the MD method is used to solve the SCB of three regions, China, North China, and South China. The characteristics of the regional clocks are analyzed by using the global clock as the reference. The regional effect bias REB is introduced to measure the deviation of the calculated regional clock from the true value, the accuracy of the regional satellite clock is evaluated, and the PPP is used to verify the regional clock positioning results. The conclusions are as follows:


the station is small, for weakened regional influence, the higher latitude station can be appropriately considered to calculate the SCB.


**Author Contributions:** Conceived the idea, H.W. and W.L.; designed the software, collected the data, and analyzed the experimental data, W.L. and P.L.; collected the related resources and supervised the experiment, W.L. and H.W.; proposed the comment for the paper and experiment, H.M., Y.R., B.L., Y.C. and H.W.; investigation, W.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research is supported by the Key Project of China National Programs for Research and Development (No. 2022YFB3903902; No. 2022YFB3903900), the Wenhai Program of the S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao) (No. 2021WHZZB1000, No. 2021WHZZB1005), the National Natural Science Foundation of China (No. 42274044; No. 41874042), the State Key Laboratory of Geo-Information Engineering and Key Laboratory of Surveying and Mapping Science and Geospatial Information Technology of MNR, CASM (No. 2022-01-09; No. 2021-01-01), and the Scientific Research Project of Chinese Academy of Surveying and Mapping (No. AR2101; No. AR2203; No. AR2214).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors acknowledge IGS (International GNSS Service) for GNSS observations and CODE (Center for Orbit Determination in Europe), WHU (Wuhan University), and GFZ (Deutsches GeoForschungsZentrum) for GNSS products. Additionally, some of the figures are produced by GMT (Generic Mapping Tools).

**Conflicts of Interest:** The authors declare no conflict of interest.
