Enhanced Detection of P-wave onset: A Novel Algorithm for Accurate P-Wave Picking

Sandeep .

Submitted September 7, 2025, SCEC Contribution #14239, 2025 SCEC Annual Meeting Poster #210

Globally, Earthquake Early Warning (EEW) system function as a national disaster mitigation technique for seismically active countries. Accuracy in P-wave picking being one of the major hurdles in EEW system for providing timely alerts in different regions worldwide. This research introduces a novel P-wave picking algorithm designed for P-Alert data, aiming to enhance the accuracy and reliability of EEW system. It utilizes the concept of an envelope, which is constructed from the absolute value of the analytic signal ℵ(s(t)). This analytic signal composed of the original waveform s(t) and its Hilbert transform h(t). Subsequently, a threshold value is calculated based on the standard deviation of the envelope to identify sudden changes in envelope amplitude. Unlike traditional (STA/LTA, STA-LTA, AIC and wavelet transform) and advance methods (Artificial neural networks, Wave polarization analysis) this algorithm doesn’t require prior knowledge or tuning of parameters related to window length, signal intensity, frequency content, and detection thresholds. Additionally, this developed algorithm is not sensitive to noise spikes in the data and performs well even in low SNR conditions. Furthermore, this algorithm has been tested on 900+ earthquake records of various magnitudes. The maximum relative error of 4% from all records confirms the applicability of this algorithm. The newly developed algorithm is crucial for minimising false alarms and enhancing the reliability of EEW systems, which are essential in earthquake-prone regions worldwide.

Key Words
Earthquake Early warning System

Citation
., S. (2025, 09). Enhanced Detection of P-wave onset: A Novel Algorithm for Accurate P-Wave Picking. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)