基于L1范数统计的单纯形微震震源定位方法

针对经典定位方法中存在的求解系统发散、定位精度低和定位受微震台网影响大等问题,采用L1范数统计对微震震源定位进行残差分析,推导得到了基于L1范数统计的事件残差计算公式;提出了微震震源定位的误差空间概念,它的实质是微震监测区域中事件残差对震源定位误差的反映;将震源的时间维数从误差空间中分离出去,建立了基于L1范数统计的单纯形微震震源定位方法,该方法不仅对到时和波速等输入数据中误差较大的离群点具有较高的抗干扰性,而且在震源求解时不会发生发散问题,具有很好的稳定性和强健性;通过现场爆破实验对算法的优越性进行了验证。研究结果表明:基于L1范数统计的单纯形算法震源定位结果稳定,定位精度高;而且算法受震源和微震台网相对位置影响较小,能够有效抵抗微震台网扩散效应对震源定位的影响,保证了台网边缘或外部震源定位的稳定性和精度;另外它还能够降低微震台网在方向控制上对定位精度的影响,提高了垂直方向上的震源定位精度。

Simplex microseismic source location method based on L1 norm statistical standard

For the classical source location algorithms，there are some problems on divergence and low source location accuracy.The source location results are affected severely by the microseismic network.In order to solve these problems，the L1 norm statistical standard was utilized in microseismic source location for the residual analysis，and the precise formulas for the calculation of station and event residuals were derived for L1 norm statistical standard.Then the concept of error space was proposed.The essence of error space is the misfit between any points of the entire monitored region and the real microseismic source.It is reflected by the values of event residual.The origin time of the source was separated in the error space and the Simplex microseismic source location method based on L1 norm statistical standard was finally built.There is no divergence problem by using the Simplex algorithm.In addition，it has better ability to handle the data with relatively large errors.The results from the field blasting tests show that：the Simplex microseismic source location method based on L1 norm statistical standard can provide better results with high accuracy and stability.This method is less affected by the relative position of the sources and the microseismic network，which makes it resist the geometrical spreading effect of the microseismic network effectively.Therefore，the accuracy and stability of the source location which located in the edge or outside of the network can be guaranteed.In addition，it can reduce the influences of the direction control of the microseismic network，which can greatly improve the source location accuracy on vertical direction.