基于改进的STA/LTA方法的微地震P波自动拾取技术

基于STA/LTA方法,提出了一种改进的自动拾取P波到时算法.引入权重因子K,构建了一种新的特征函数,提出寻找STA/LTA曲线上的最大值对应时刻为P波到时的方法,并运用Matlab对冬瓜山铜矿微震事件进行初至拾取分析.结果表明:该方法能够准确地拾取微地震P波初至,减少了传统的STA/LTA算法需要调整触发阈值(Thr)的过程,克服了固定阈值不能适应复杂多变信号到时拾取的缺点,具有抗噪性强、稳定性强、拾取精确度高等优势.

Automatic Picking of Microseismic Events P-wave Arrivals Based on Improved Method of STA/LTA

An improved method of automatic picking P-wave first arrival time based on the method of STA/LTA was put forward. A new kind of characteristic function was established by introducing weighting factor K， the global maximum on the curve of STA/LTA was found， then the corresponding moment is identified as the arrival of P-wave， and Matlab was used to analyze seismic events. Results show that the method can accurately pick up P-wave arrivals of seismic event， and reduce the process of adjusting the trigger threshold (Thr) to pick up the P-wave of the traditional algorithm (STA/LTA)， and overcome the shortcoming that a fixed threshold can not pick the arrival time of complex signals. And the method has advantages of strong noise resistance， good stability， etc.