大地电磁测深资料的噪声干扰

在概述大地电磁场场源的基础上,阐明了影响大地电磁测深资料的噪声分为场源噪声、地质噪声和人文噪声,它们分别来自不同的源。研究了各种噪声对大地电磁测深资料的影响特点,并对几种常见的噪声干扰信号进行了频谱分析。结果表明地质噪声一般影响全频域,近场干扰主要影响高频的有限频率,但近处雷电影响高频的较宽频带,而负荷系统的不稳定则主要影响低频。最后提出了消除或降低各种噪声干扰的可能办法或建议。

THE NOISE INTERFERENCE OF MAGNETOTELLURIC SOUNDING DATA

On the basis of a discussion on the source of magnetotelluric field,this paper points out that the noises affecting magnetotelluric sounding data can be divided into field source noise,geological noise and human noise,which are derived from different sources.The authors studied the influences of various sorts of noises upon the magnetotelluric sounding data and made frequency spectrum analysis for several sorts of common noise interferences.The geological noise commonly affects the whole frequency domain,and the near field interference mainly affects the limited frequency of high frequency.Nevertheless,the nearby thunder and lightning affect relatively wide frequency band of the high frequency,whereas the unstability of the load system mainly affects the low frequency.Finally,some suggestions are made concerning the elimination or reduction of various noise interferences.