Algorithm Indicating Moment of P-Wave Arrival Based on Second-Moment Characteristic

• Published in: Shock and vibration Vol. 2016; no. 2016; pp. 1 - 6
• Main Authors: Wylomanska, Agnieszka, Zimroz, Radoslaw, Obuchowski, Jakub, Sokolowski, Jakub, Koziarz, Eugeniusz
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2016; John Wiley & Sons, Inc; Wiley
• Subjects: Algorithms; Arrivals; Automation; Copper industry; Expected values; Fittings; Methods; Neural networks; Noise; Partitioning; Seismic phenomena; Standard deviation; Time series; Underground mines; Vibration; Wavelet transforms
• ISSN: 1070-9622; 1875-9203; 1875-9203
• DOI: 10.1155/2016/4051701

The moment of P-wave arrival can provide us with many information about the nature of a seismic event. Without adequate knowledge regarding the onset moment, many properties of the events related to location, polarization of P-wave, and so forth are impossible to receive. In order to save time required to indicate P-wave arrival moment manually, one can benefit from automatic picking algorithms. In this paper two algorithms based on a method finding a regime switch point are applied to seismic event data in order to find P-wave arrival time. The algorithms are based on signals transformed via a basic transform rather than on raw recordings. They involve partitioning the transformed signal into two separate series and fitting logarithm function to the first subset (which corresponds to pure noise and therefore it is considered stationary), exponent or power function to the second subset (which corresponds to nonstationary seismic event), and finding the point at which these functions best fit the statistic in terms of sum of squared errors. Effectiveness of the algorithms is tested on seismic data acquired from O/ZG “Rudna” underground copper ore mine with moments of P-wave arrival initially picked by broadly known STA/LTA algorithm and then corrected by seismic station specialists. The results of proposed algorithms are compared to those obtained using STA/LTA.