地震电磁卫星交变电磁场的数据处理

Data processing of alternating electromagnetic field recorded by seismic electromagnetic satellite

地震电磁卫星的迅速发展也带来了一些相关的研究课题,本文根据地面地震电磁观测中成熟的监测手段和参数,来分析如何根据地震电磁卫星记录的电、磁场分量提取可能与地震电磁异常现象有关的信息.介绍了电磁场时间序列的幅值统计;电磁波谱尤其是自功率谱对噪音干扰敏感,介绍了自功率谱的计算方法;正交电磁场相关度的变化分析方法;空间电磁波平面特征指标求取;以及在简单平面波特征下,提出空间阻抗张量的计算方法.

The rapid developing of earthquake electromagnetism satellite also requires some related areas to be studied. According to the well-done methods and parameters in the processs of ground earthquake electromagnism monitoring, we analyze the possibility of extracting possible abnormal earthquake information by analysis the electromagnetic time series recorded by satellite. Firstly, to analyze the statistic characteristics of electromagnetic signal. Secondly, the autospectra is much more sensitive to noise, so to introduce the formula of autospectra. Thirdly, the coherence is also a sensitive parameter to noise, the orthogonal electrical and magnetic fields have coherence value close to 1, while the orthogonal magnetic fields have coherence value close to 0, both values will change much by noise. Forthly, the electromagnetic planarity is an important parameter to analyze the spatial electromagnetic fields, the electromagnetic planarity index is introduced. Fifthly, as the resistance tensor is a very important parameter in magnetitellurics, it＇s also the same with electromagnic fields recorded by earthquake electromagnetism satellite, and the space resistance tensor is also introduced.