中文摘要：

根据安徽庐枞大地电磁资料，研究了各种干扰噪声对大地电磁测深资料影响的特点，并对几种常见的噪声干扰信号进行了频谱分析，展示了相关干扰信号的时间序列特征和典型视电阻率一相位曲线，将影响大地电磁测深资料的噪声干扰分为工频干扰噪声，地质噪声和其他外界、观测系统不稳定造成的干扰噪声，它们分别来自不同的场源。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，而大功率用电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一些建议。

英文摘要：

Based on magnetotelluric data of Luzong area of Anhui Province,the authors studied the effects of various interference noises on magnetotelluric sounding data,made frequency spectrum analysis of several noise interference signals,and presented time series characteristics of relevant interference signals as well as apparent resistivity-phase curves.This paper has clarified the fact that noise interference that affects magnetotelluric sounding data can be divided into field source noise,geological noise and other interference noises caused by instabilities of outer factors and the observation system,which are derived from different sources.The results obtained by the authors show that the geological noise generally affects the whole frequency domain,the near-field interference mainly affects limited frequency of the high frequency,and the instability of the large power electric system mainly affects low frequency.Some suggestions are put forward in this paper for eliminating or reducing various kinds of noise interference.