Abstract: This study investigates the applicability of BeiDou Navigation Satellite System Interferometric Reflectometry (BDS-IR) technology for river water level monitoring,aiming to address the limitations of traditional methods,such as insufficient spatio-temporal coverage and high construction and operational costs.A dual-frequency signal (B1I/B2I) interference physical model is established,integrated with a multi-path effect characteristic parameter inversion algorithm.Dynamic water level monitoring experiments are conducted in typical reaches of the middle Yangtze River,and the results are validated against data from hydrometric stations.The validation shows that the root mean square error (RMSE) between the BDS-IR derived water levels and the reference data is 1.13 cm,with a correlation coefficient of 0.97,achieving centimeter-level inversion accuracy.The findings demonstrate that BDS-IR technology offers a high-precision and low-cost technical solution for watershed flood control,disaster mitigation,and intelligent water resource management.

Key words: BeiDou Satellite Navigation System, interferometric reflectometry, multi-path effect, water level monitoring, water level inversion, signal processing