摘要
随着工业文明的发展,大量的电磁噪声混入观测数据中,导致数据出现畸变,成为限制电磁勘探质量的瓶颈问题。本文通过分析强电磁干扰地区含噪电磁场观测数据的信噪特征,针对性地开展抗噪处理技术研究。在天然场源及人工场源大地电磁法的理论基础上,提出了采用远参考技术、聚类分析及Rhoplus数据拟合的多方法融合抗噪处理方案。天然场电磁信号采用远参考技术和Rhoplus数据拟合处理;人工场源采用伪随机信号激励,数据采用聚类分析去噪。经过测试统计,对于天然场含噪大地电磁数据,该处理方案对50Hz工频干扰的压制率达到了85%,低频段视电阻率离散度降低了60%;对于人工场源含噪数据,80%的响应数据在1 Hz左右低频段的估算质量得到明显改善。表明该处理方案能够有效压制强电磁噪声影响,提高含噪大地电磁数据的稳定性和可靠性,能更准确地反映地下地质结构的真实情况。
With the development of industrial civilization,a large amount of electromagnetic noise has been mixed into observation data,leading to data distortion and beco ming a bottleneck that limits the quality of electromagnetic exploration.This article analyzes the signal-to-noise characteristics of noisy electromagnetic field observation data in areas with strong electromagnetic interference,and conducts targeted research on anti-noise processing techniques.On the basis of the theory of natural-source and artificial field source magnetotelluric methods,a multi-method fusion anti-noise processing scheme is proposed combing far reference technology,cluster analysis,and Rhoplus data fitting.The natural electromagnetic signal is processed using remote reference technology and Rhoplus data fitting;The artificial field source is excited by pseudo-random signals,and the data is denoised using cluster analysis.After testing and statistical analysis,for natural field noisy magnetotelluric data,this processing scheme achieved a suppression rate of 85%against 50 Hz power frequency interference,and reduced the apparent resistivity dispersion in the low-frequency range by 60%;for noisy data from artificial sources,80%of the response data showed a significant improvement in estimation quality in the low-frequency range around 1 Hz.This indicates that the proposed scheme can effectively suppress the influence of strong electromagnetic noise,improve the stability and reliability of noisy magnetotelluric data,and more accurately reflect the true situation of underground geological structures.
作者
卿志
Qing Zhi(China Railway Fourth Survey and Design Institute Group Co.,Ltd.,Wuhan Hubei 430063,China)
出处
《工程地球物理学报》
2025年第5期547-555,共9页
Chinese Journal of Engineering Geophysics
基金
中国铁建股份有限公司科技研发计划项目/地质信息数字化平台研发与应用示范(编号:2021-A02)。
关键词
电磁勘探
强电磁干扰
信噪特征
远参考
聚类分析
Rhoplus拟合
electromagnetic exploration
strong electromagnetic interference
signal-to-noise characteristics
distant reference
cluster analysis
rhoplus fitting
