基于我国青藏高原东北缘地区的5个地电场观测台站2015年以来的长时段地电场数据,首先使用求取两信号互相关函数的方法压制了大部分不相关电磁扰动,然后通过高通滤波和信号的频谱、自功率谱和互功率谱分析,得到了互相关分析后各台站的时频变化情况,结果显示在1 Hz采样数据中10-3-10-1 Hz部分可能含有地电脉动信号.同时通过对大武台原始数据进行小波变换分析,并将同时段地电场观测与相关频段的地磁场观测进行对比,结果表明,地球电场在该频段内表现出Pc3-5的特点,地电脉动成分占优势,且10-3-10-1 Hz频段的能量较高,这一现象可能与地球磁层和电离层辐射波的稳定性有关.%The geomagnetic pulsation,which is in the period of 0.2-600 s and appears at a particular moment,is an important component of the geomagnetic field.However,there is no uniform understanding about the ultra-low frequency (ULF) components of the geoelectric field and how is it changing,the main reason is perhaps the lack of the observation data to support study.In the paper,we calculate cross-correlation function of two signals based on the geoelectric field data with ultra-low frequency (1 Hz) from five observation stations around northeastern margin of Tibet Plateau since 2015.Consequently,the most uncorrelated electromagnetic disturbance may be suppressed.By the way of high pass filter,frequency spectrum,auto-power spectrum and cross-power spectrum of the signals,the result show that the sampling data in the frequency band of 10-3-10-1 Hz perhaps contains geoelectric pulsation signal.At the same time,through comparison with the analytical result of the relevant frequency bands of the geomagnetic field,we draw the conclusion that the geoelectric field within the frequency band 10-3-10-1 Hz shows the characteristics of the Pc3-5,in addition,the 10-3-10-1 Hz frequency band had the largest spectrum.This phenomenon may be related to the stability of the magnetosphere and the ionospheric radiation.
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