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对数字多道预测滤波技术应用于排除小型地震地磁台网短周期总强度数据噪声的有效性进行了探讨．结果表明，该技术可以通过利用外源磁扰矢量来有效地拟合总强度差值中的内源电磁感应差值场，从而成功地降低差值的噪声水平．本文采用的两对差值实例中，滤波质量因子Ｑ分别达到０．８６和０．６８．频谱分析表明，在无大的地磁事件发生的通常情况下，拟合差值的周期成分以与Ｓｑ变化周期相应的１～４次谐波为主．最佳滤波器的长度主要取决于差值中可预测能量频率的高低，同时，还可能与输入和期望输出间的位相差异有关．研究表明，难以得到同时满足磁扰日与磁静日的普适滤波器．对京西延庆－怀来盆地地磁资料的实例分析，显示出该地区地下电导率的分布可能极不均匀．
The effectiveness of digital multi-channel prediction filtering technique in eliminating short-period total intensity data noise of small-scale seismic geomagnetic network is discussed. The results show that this technique can successfully reduce the noise level of the difference by effectively using the exogenous magnetic disturbance vector to fit the difference field of intrinsic electromagnetic induction in the total intensity difference. In this paper, two pairs of difference examples, the filter quality factor Q respectively 0.86 and 0.68. Spectrum analysis shows that in the normal case of no large geomagnetic event, the periodic components of the fitted difference mainly dominate the 1st ~ 4th harmonics corresponding to the period of Sq variation. The length of the optimal filter depends mainly on the level of the predictable energy frequency in the difference and may also be related to the phase difference between the input and the desired output. Studies have shown that it is difficult to obtain a pervasive filter that satisfies both the magnetic disturbance day and the magnetic static day. The case study of geomagnetic data in the Yanqing-Huailai Basin in western Beijing shows that the distribution of underground conductivity in the area may be extremely uneven.