基于时窗能量比与互信息量的微地震初至拾取方法

Automatic first arrival pickup method of microseismic event based on energy ratio and mutual information

由于微地震事件本身能量弱、资料信噪比低的特点,初至快速精确的拾取成为其关键而又亟待解决的问题。针对微地震事件初至人工拾取效率低、时窗能量比方法拾取精度低的特点,从信息熵和互信息量的角度开始研究,根据互信息量是随机变量间统计依存性与关联程度的量度特点,研究了一种时窗能量比与互信息量准则的微地震初至拾取方法,首先以时窗能量比算法来粗略估计初至的到达时刻,然后再利用互信息量算法来准确的拾取初至,通过模型验证与实际数据的测试,并与常规方法对比分析,验证了方法的有效性与可行性,能够较为准确与快速地实现微地震初至的自动拾取。

Due to the weak energy microseismic events and the characteristics of low SNR data,the quick and accurate first arrival pickup has become the key problem. In view of the low efficiency of manual pickup and the low accuracy energy ratio method in picking up first arrival,the authors proposed entropy and mutual information method. Through studying the features of random variables and correlation degree,the authors proposed a first arrival pickup based on energy and mutual information. First,energy ratio algorithm is used to pick a rough arrival time,and then the mutual information algorithm is used to accurately pick up arrival time. According to the test of the model and the analysis of real data in comparison with conventional methods,the authors effectively verify the accuracy and feasibility of the method. The automatic first arrival pickup is achieved accurately and rapidly.