地球自由振荡探测中最佳时间窗口的确定  

Determination of the optimal time window for the earth’s free oscillation detection

作　　者：邓文彬[1] 杨露 胡新玲[1] 许闯 DENG Wenbin;YANG Lu;HU Xinling;XU Chuang(College of Architectural Engineering,Xinjiang University,Urumchi 830046,China;School of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006,China;State Key Laboratory of Geodesy and Earth’s Dynamics,Institute of Geodesy and Geophysics,CAS,Wuhan 430077,China)

机构地区：[1]新疆大学建筑工程学院,乌鲁木齐830046 [2]广东工业大学土木与交通工程学院,广州510006 [3]中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室,武汉430077

出　　处：《测绘科学》2020年第3期23-27,共5页Science of Surveying and Mapping

基　　金：国家自然科学基金项目(51868074,51368056);2016自治区高校科研计划项目(XJEDU2016I015);2016新疆大学博士科学基金项目(BS160250);大地测量与地球动力学国家重点实验室开发基金项目(SKLGED2018-1-3-E)。

摘　　要：针对当前地球自由振荡信号探测所采用数据的时间窗口位置和长度难以给出统一标准的问题,该文以信噪比为衡量指标,系统地讨论利用超导重力观测数据检测地球自由振荡信号的最佳时窗选择。研究结果表明:确定最优时间窗口的位置和长度,需要进行不断实验;0S0最佳探测的时间窗口位置为震后2 440 min,数据长度为7 200 min,此时0S0的估计值与PREM模型的差异约为5.86×10^-4,差异极小;通过对不同振型自由振荡进行分析发现,不同振型的最佳时间窗口是不同的。该方法也可以推广至相关信号探测的应用中。Aiming at present situation that there were no standards regarding the location and length of time window for adopted data to detect the Earth’s free oscillation.Based on the measurement index of signal to noise ratio,the determination of the optimal time window for detecting the Earth’s free oscillations using superconducting gravity data was systematically analyzed in the present study.The results showed that in order to determine the optimal time window,repeated iterations were needed.The optimal location and length of time window for detecting 0S0 were 2 440 minutes after the event and 7 200 minutes.The error between our estimation and that from PREM model was approximately 5.86×10^-4.According to the analysis of different free oscillations,the optimal time windows for various normal modes were different.Our approach could be also applied to relative signal detection.

关 键 词：地球自由振荡 信噪比 时间窗口 超导重力 

分 类 号：P312[天文地球—固体地球物理学]