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The Earth's natural pulse electromagnetic fields for earthquake time–frequency characteristics: Insights from the EEMD–WVD method 下载免费PDF全文
Monitoring the Earth's natural pulse electromagnetic field (ENPEMF) signal is a geomagnetic detection approach for the Earth internal and external studies, and it provides a reference for earthquake prediction. In this paper, the Ensemble Empirical Mode Decomposition–Wigner Ville Distribution (EEMD–WVD) method is used to process the time sequences of the ENPEMF signal detected by GR‐01 receiving devices during the Lushan MS7.0 earthquake (April 20th, 2013). By obtaining the intrinsic mode function (IMF), the time–frequency–amplitude joint distribution and the energy spectrum of the ENPEMF signal, the suspected anomalies before the earthquake could be shown. The results illustrate the ENPEMF signal before an earthquake and its time–frequency characteristics based on an EEMD–WVD algorithm, proving useful information about the anomalies around the time of the earthquake. 相似文献
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浅海中的宽带水声信号传播呈现出频散的特点,通过高分辨率的时频分析方法可以刻画频散曲线。通过数值仿真和实验数据处理,对比分析几类常用的时频分析方法在提取宽带声信号频散曲线方面的性能。结果表明:STFT时频局部化精度不够高;在较强频散的情况下,DSTFT时频分辨率较高。WVD时频聚集性最好,但是有严重的交叉项干扰;固定核函数的CWD较好地抑制交叉项,时频分辨率虽优于STFT,但弱化了时频聚集性;AOK时频分布采用自适应高斯核函数,在抑制交叉项的同时,时频聚集性较好,有望较好地用于提取信号频散曲线。 相似文献
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时频峰值滤波信号增强方法在实际地震资料处理中的应用 总被引:1,自引:0,他引:1
在不损失有效信号能量的基础上从低信噪比地震资料中恢复出有效信息是地震资料处理的关键问题之一。针对这一问题利用基于伪Wigner-Ville分布的时频峰值滤波技术处理共炮点地震记录。基于伪Wigner-Ville分布的时频峰值滤波技术可以保证得到复杂地震记录的无偏估计,增强地震资料中的有效信息,去除随机噪声,有效地恢复同相轴。采用实际共炮点地震资料,比较时频峰值滤波前后的地震记录可以看出:地震资料中的有效信息明显增强,同相轴连续性得到改善。 相似文献
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