一种地震P波和S波初至时间自动拾取的新方法

发布时间：2019-02-25 14:08

【摘要】：地震P波、S波初至时间的拾取是地震波分析的一项基础性工作.本文提出了一种新的地震波初至时间自动拾取的方法:首先,把地震波的三分量时程曲线变换为一组空间向的能量变化率时程曲线;然后对能量变化率时程曲线进行STA/LTA(Short Time Average/Long Time Average,短时间的均值/长时间的均值)处理,拾取地震P波和S波的大致初至时间;最后提出采用一种二次方自回归模型对初至附近的能量变化率曲线进行二次方自回归处理,精确拾取出P波和S波的初至时间.本文采用了10组芦山地震的记录数据和150组汶川地震的记录数据对此方法的可靠性进行了检验.以人工拾取结果为参考,此方法具有很高的准确率和稳定性,同时,相比于常用的STA/LTA方法和AIC(Akaike Information Criterion,Akaike信息准则)方法,此方法在计算时间效率方面稍微逊色,但是对S波初至时间的拾取精度和可靠性更高.此方法丰富了地震P波、S波初至时间的自动拾取方法.
[Abstract]:It is a basic work of seismic wave analysis to pick up the first break time of P-wave and S-wave. In this paper, a new method for automatically picking up the first arrival time of seismic waves is presented. Firstly, the three-component time-range curves of seismic waves are transformed into a set of time-range curves of the rate of energy change in the spatial direction. Then the time-range curve of energy change rate is processed by STA/LTA (Short Time Average/Long Time Average, short-time mean / long-time mean, and the approximate first arrival time of P-wave and S-wave is picked up. Finally, a quadratic autoregressive model is proposed to deal with the energy change rate curve near the first arrival, and the first arrival time of P wave and S wave can be accurately picked up. In this paper, the reliability of this method is tested by using 10 sets of recorded data of Lushan earthquake and 150 groups of recorded data of Wenchuan earthquake. Based on the manual pick-up results, this method has high accuracy and stability. At the same time, compared with the commonly used STA/LTA method and AIC (Akaike Information Criterion,Akaike information criterion, this method is a little less efficient in calculating time. However, the picking accuracy and reliability of the first arrival time of S wave are higher. This method enriches the automatic pickup method of the first arrival time of P wave and S wave.
【作者单位】：中国地震局工程力学研究所地震工程与工程振动重点实验室;
【基金】：国家青年自然科学基金(51508536)资助
【分类号】：P631.4

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