BDS PPP-RTK for deformation monitoring of Hong Kong-Zhuhai-Macao bridge

• Published in: Measurement : journal of the International Measurement Confederation Vol. 257; p. 118651
• Main Authors: Zhong, Hailin, Gao, Rui, Zha, Jiuping, Ye, Fei, Zhang, Baocheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2026
• Subjects: BDS; Deformation monitoring; Hong Kong-Zhuhai-Macao Bridge; PPP-RTK; DPM; GMF; CLK; HZMB; GNSS; InSAR; ION; DFM; JHWB; LAMBDA; BDS; GEO; MAE; PDOP; PPP; Hong Kong-Zhuhai-Macao Bridge; QZWB; Deformation monitoring; MEO; IGSO; RMS; PPP-RTK; ECEF
• ISSN: 0263-2241
• DOI: 10.1016/j.measurement.2025.118651

•The experimental subject is the Hong Kong-Zhuhai-Macao Bridge (HZMB), the world's longest sea-crossing bridge (55 km).•The performance of the BDS PPP-RTK for deformation monitoring in the Asia-Pacific region is evaluated for the first time.•The phenomena of periodic temperature-induced deformation and the deformation lag have been observed.•The BDS PPP-RTK enables millimeter-level deformation monitoring accuracy in the Asia-Pacific region. The Hong Kong-Zhuhai-Macao Bridge (HZMB) has significantly boosted regional economic development, but its unique structure and geographical location pose challenges for deformation monitoring, which is essential for safe operation. The continuous improvement and increasing number of satellites in the BeiDou Navigation Satellite System (BDS), improves positioning accuracy and convergence speed, offering new opportunities for bridge deformation monitoring. Given the current scarcity of research on deformation monitoring based on BDS, especially for long-span bridges, this study aims to evaluate the BDS PPP-RTK performance in deformation monitoring of HZMB. Based on high-frequency BDS observations (1 Hz) from a reference network and three bridge monitoring stations, we employed the PPP-RTK to extract 3-day deformation values of HZMB. These results were then compared with Ionosphere-Float RTK (IF-RTK) and high-precision displacement sensors. The analysis shows that the PPP-RTK can directly achieve longitudinal accuracy of 6 mm RMS and vertical accuracy of 1.6 cm RMS in deformation monitoring. After smoothing results, the longitudinal accuracy and vertical accuracy can be improved to 3 mm RMS and 6 mm RMS respectively. By comparison, PPP-RTK demonstrates superior accuracy over IF-RTK in both the longitudinal and vertical directions. Additionally, we observed periodic deformation trend in HZMB, which was attributed to temperature changes. All results confirm that the BDS PPP-RTK method is reliable and effective in deformation monitoring of HZMB, and BDS is capable of independently achieving millimeter-level deformation monitoring. This can serve as a valuable reference for scheme design of GNSS deformation monitoring, particularly in BDS-only scenarios.