Automated S-Wave Arrival Timing in GNSS Instantaneous VelocityData Without Frequency-Domain Pre-Filtering

EGU 2025 PosterGSWPicker is scientific software that automatically detects when seismic shear waves arrive and measures how strong and how long ground shaking lasts, using GNSS (Global Navigation Satellite Systems) velocity data.<br>The software reads GNSS position data or difference position data from various processing engines (such as PRIDE PPP and VarioPy). It converts these time series into instantaneous velocities and then runs a three-step process:<br>1. It first reduces noise in the velocity data.<br>2. It then identifies ground shaking signals using three independent methods: two statistical approaches (Median Absolute Deviation and least-squares) and a hypothesis testing method (w-test).<br>3. Finally, it determines the exact time when shear waves arrive and measures the strength and duration of ground shaking.<br>This process allows seismic analysis to be performed on GNSS data automatically, without the need for manual pre-filtering.