Real-time GNSS seismometer and its accuracy

Real-time high-rate GNSS data can be used to obtain the dynamic ground displacements caused by earthquakes. The displacements are greatly useful in earthquake early warning and emergency response. A real-time GNSS seismometer system is built with real-time precise point positioning (RTPPP) and displacement waveforms detection techniques. In order to evaluate the accuracy of real-time displacement waveforms derived from RTPPP, simulated data from a shaking table platform, which can generate the dynamic displacements, and real-world data of the 2010 Baja California earthquake are processed. Comparing the above results with those of Inertial Measurement Unit (IMU), precise point positioning (PPP) and relative positioning, it is illustrated that the real-time GNSS seismometer system is able to obtain the displacement waveforms with the accuracy of better than 1 cm and 3 cm in horizontal component and vertical component, respectively. The displacement waveforms of Baja California earthquake detected by this GNSS seismometer system are consistent with the results released by Southern California Earthquake Data Center (SCEDC).