A Method for Real-time Coseismic Displacement Monitoring Based on BDS PPPB2b Correction Signals

Objectives: For real-time Precise Point Positioning (PPP) solutions, precise satellite orbit and clock correction products are required, and it heavily relies on issues such as network transmission. Methods: This paper proposes a real-time monitoring method for coseismic displacement based on BeiDou Navigation Satellite System (BDS) PPP-B2b correction signals, which enables direct utilization of GNSS receivers to simultaneously receive observation data and correction signals for real-time precise positioning. Results: By retrospectively inverting 1 Hz GNSS observation data for the 2022 Luding Ms 6.8 earthquake in Sichuan, the average RMS of static PPP in the horizontal direction based on B2b correction products can reach 1-2 cm, and in the vertical direction can reach 2-4 cm. In the kinematic PPP mode, using WUM precise products as a reference, the displacement waveforms calculated based on B2b correction products have differences of only 0.56 cm and 1.08 cm in the east and north directions, respectively. The magnitude of the Luding earthquake determined using the displacement waveforms from B2b products and WUM products is Ms 6.76 and Ms 6.67, respectively. Compared with the magnitude announced by the China Earthquake Administration, they differ by only 0.04 magnitude units. Conclusions: This study indicates that the PPP method based on BDS B2b correction signals can be applied to realtime seismic monitoring and rapid determination of seismic parameters.