基于瞬时相位的微地震干涉定位方法研究  

Research on microseismic interferometric location method based on the instantaneous phase

作　　者：战婷婷 李磊 陈浩[1,2,3] ZHAN TingTing;LI Lei;CHEN Hao(State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Engineering Research Center of Sea Deep Drilling and Exploration,Beijing 100190,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education,Changsha 410083,China)

机构地区：[1]中国科学院声学研究所声场声信息国家重点实验室,北京100190 [2]中国科学院大学,北京100049 [3]北京市海洋深部钻探测量工程技术研究中心,北京100190 [4]中南大学地球科学与信息物理学院,长沙410083 [5]有色金属成矿预测与地质环境监测教育部重点实验室(中南大学),长沙410083

出　　处：《地球物理学报》2022年第5期1753-1768,共16页Chinese Journal of Geophysics

基　　金：国家自然科学基金资助项目(11734017,42004115,11574347)资助.

摘　　要：波形叠加定位法具有自动性和抗噪性等优点,已被广泛应用于微地震事件定位.当该类方法采用特征函数变换原始波形以克服初至极性变化影响时,会降低成像分辨率.而将相位加权叠加法应用于微地震成像时,虽然提高了成像分辨率,但并未考虑复杂震源机制对定位的影响.为了校正波形极性,并提高干涉成像法的分辨率和压制噪声的能力,本文重新组合了原始互相关波形的振幅和瞬时相位信息,提出了互相关相位加权成像法(CCPW).通过数值算例对比了互相关相位加权成像法(CCPW)、基于绝对值干涉成像法(AII)和基于长短时窗能量比干涉成像法(SLII),讨论了不同方法在抗噪性和成像分辨率等方面的性能.理论测试结果表明:新方法能够校正波形极性变化,具有较强的抗噪性,提高了成像分辨率.最后将三种方法应用于地面监测的实际矿震数据中,验证了新方法的有效性.The waveform stacking-based location methods have been widely used for the microseismic event location due to their automaticity and noise-resistance.The imaging resolution of these methods will be reduced when characteristic functions for original waveform transformation are used to overcome the effect of first-motion polarity changes.Although the imaging resolution is improved,the phase-weighted stack method does not consider the effect of complex source mechanisms on location when it is applied to microseismic imaging.In order to correct the waveform polarity,and to further improve the resolution and noise-resistance ability of the interferometric imaging method,this work proposes a cross-correlation phase-weighted(CCPW)imaging method which recombines the amplitude and instantaneous phase information of the original cross-correlation waveform.The performance of the cross-correlation phase-weighted(CCPW)imaging method,absolute value-based interferometric imaging(AII),and short-term average to long-term average ratio(STA/LTA)-based interferometric imaging(SLII)is investigated by numerical examples,in terms of noise-resistance,imaging resolution and so on.The numerical tests indicate that the new method can address the first-motion polarity changes,have strong anti-noise performance,and improve the imaging resolution.Finally,these three methods are applied to field mining-induced seismicity monitored by surface stations and the effectiveness of the new method is verified.

关 键 词：微地震定位 干涉成像 瞬时相位 互相关叠加 

分 类 号：P631[天文地球—地质矿产勘探]