一种基于选权迭代法的震中估计方法

An Epicenter Location Method Based on Selecting Weight Iteration

强震仪提取P波到时容易出现误判现象,导致地震到时观测信息不准确,造成Geiger方法的震中估计精度降低。针对该问题,首先采用STA/LTA+AIC方法,提取地震P波到时;其次,基于选权迭代法的抗差估计进行震中位置解算,抵抗P波到时信息可能存在的粗差影响。利用6次地震事件对本文方法进行验证,结果表明,Geiger方法的震中平均偏差为22.48 km、均方根误差RMSE为19.44 km,获取的发震时刻平均偏差为4.1 s、RMSE为4 s;基于选权迭代法的震中估计新方法的震中平均偏差为12.59 km、RMSE为11.00 km,获取的发震时刻平均偏差为2.3 s、RMSE为2 s。相较于传统Geiger方法,新方法的震中估计精度提高43%,发震时刻获取精度提高50%,可有效减弱P波到时粗差对震中估计结果的影响,提高计算结果的准确性。

We propose an epicenter location method based on selecting weight iteration.This method aims to enhance the accuracy of epicenter location in the presence of misjudgments in P-wave arrival times.The approach first employs the STA/LTA+AIC method to extract seismic P-wave arrival times.Then,it utilizes selection weight iteration to calculate the epicenter location,effectively mitigating potential gross errors in the P-wave arrival time information.We validate the method through experiments involving six seismic events and compare the results with those obtained using the traditional Geiger method.The average deviation and root mean square error(RMSE) of epicenter location are 22.48 km and 19.44 km for the traditional Geiger method,respectively.The average deviation and RMSE of the origin time are 4.1 s and 4 s,respectively.For the proposed method based on selection weight iteration,the average deviation and RMSE of epicenter location are 12.59 km and 11.00 km,respectively.The average deviation and RMSE of the origin time are 2.3 s and 2 s,respectively.The findings demonstrate that the new method improves the accuracy of epicenter location by 43% and the accuracy of origin time by 50%.This improved method effectively reduces the impact of gross errors in P-wave arrival times on the calculation results,thereby enhancing the accuracy of the calculated epicenter location.