基于高分辨率时频分析的核爆地震信号能量统计初至检测算法  

First Arrival Detection Algorithm of Nuclear Explosion Seismic Signal Energy Statistics Based on High Resolution Time-frequency Analysis

作　　者：李鸿儒 李夕海 牛超 LI Hongru;LI Xihai;NIU Chao(Rocket Force University of Engineering,Xi'an 710025,China)

机构地区：[1]火箭军工程大学,西安710025

出　　处：《核电子学与探测技术》2024年第1期180-190,共11页Nuclear Electronics & Detection Technology

基　　金：陕西省自然科学基金面上项目(2023-JCYB-221);陕西省自然科学基础研究计划项目(2023-JC-YB-244)。

摘　　要：核爆地震波检测是禁核试核查的关键环节之一。常用的短时长时能量均值比、赤池信息准则、傅里叶变换等方法虚警率都比较高,为此,提出一种基于高分辨率时频分析的核爆地震信号能量统计初至检测算法。其基本原理是根据核爆地震事件信号与噪声的频域分布差异,采用窄带分频技术将信号时域波形变换到时频域,在各频带计算局部能量均值与全局能量均值之比并进行二值化处理,当结果大于设定的阈值时,认为此频带该时刻属于地震事件信号的一部分,如果在某一阈值下出现二值化结果相同的情况,只需继续增大阈值进行检测,直到最终只有一个时间点检测到频段的数量最多即可,最大值的跳跃点即认为是初值时刻。利用地下核爆产生的地震信号进行实验研究,结果表明本文方法能够在提高检测准确率的同时解决高虚警问题,在低信噪比信号条件下具有较好的适用性与鲁棒性。The detection of nuclear explosion seismic wave is one of the key links of the CTBT.The common methods such as short-long time energy mean ratio,Akaike information criterion and Fourier transform have high false alarm rate.Therefore,a new energy statistic first arrival detection algorithm based on high-resolution time-frequency analysis of nuclear explosion seismic signals is proposed.The basic principle is that according to the difference in frequency domain distribution of nuclear explosion seismic event signal and noise,narrowband frequency division technology is used to transform the signal time-domain waveform into the time-domain frequency domain,calculate the ratio of local energy mean value to global energy mean value in each frequency band,and carry out binary processing.When the result is greater than the set threshold,the frequency band is considered to be part of the seismic event signal at that time.If the binarization results are the same under a certain threshold,it is only necessary to continue to increase the threshold value for detection until finally only one time point detects the maximum number of frequency bands,and the jump point of the maximum value is considered to be the initial value moment.The experimental results show that the proposed method can solve the problem of high false alarm while improving the detection accuracy,and has good applicability and robustness under the condition of low SNR signal.

关 键 词：核爆 初至拾取 短时长时能量比 时频分析 分频处理 

分 类 号：P31[天文地球—固体地球物理学]