微地震有效事件自动识别与定位方法

Automatic identification and localization of micro seismic effective events

微地震有效事件自动识别与定位是进行微地震实时监测的关键。自动识别的准确性对随后的震源定位精度有很大影响。本文在讨论长短时窗能量比(STA/LTA)法基础上,讨论了基于特征值分析且抗噪能力较强的识别方法。结合多道检波器相互位置及有效信号的空间相关关系,根据P、S波的传播特征,通过研究有效微地震信号在相邻道之间及多道之间的变化特征,形成了多级检波器微地震有效事件的自动识别方法。在对初至有效波进行拉平的基础上,利用叠加能量和相关特性,采用跟踪分量方法进行扫描叠加,并以非均一化互相关准则作为初至校平的判断依据,建立了微地震事件的自动扫描定位方法。应用该方法对实际资料进行有效微地震事件的识别与定位,结果与实际情况基本吻合。该方法可克服以往微地震人工识别和定位的缺陷,提高微地震监测的效率。

The automatic identification and localization of micro seismic effective events is the key of micro seismic real-time monitoring.The accuracy of automatic picking micro seismic effective events has a great impact on source location.Based on discussion about the STA/LTA method,the paper proposes a method for automatic identification and localization of micro seismic effective events.We first discuss eigenvalue analysis methods to enhance the noise immunity.Considering both the mutual location of multi-channel detectors and the correlation in space of signals,and according to the propagation characteristics of P and S waves,we can find a variation law of micro seismic signals between adjacent-channels,which is used to automatically identify micro seismic signals on the multi-channel detectors.After leveling first arrivals,we use component track scanning stack to automatically identify and localize micro seismic effective events by stack energy and correlation characteristics.The real data example shows that our results are consistent with the actual situation.