何继善^1,,
薛国强^2,3,,
1. 中南大学地球科学与信息物理学院, 长沙 410083
2. 中国科学院矿产资源研究重点实验室, 中国科学院地质与地球物理研究所, 北京 100029
3. 中国科学院大学, 北京 100049

基金项目: 国家重点研发计划（2017YFC0601204，2016YFC0600101）和国家自然科学基金（41474095，41704076）联合资助


详细信息

作者简介: 何继善, 男, 1934年生, 教授, 主要从事电磁法广域化探测方法技术研究.E-mail:hjs@mail.csu.edu.cn

通讯作者: 薛国强, 男, 1966年生, 研究员, 主要从事瞬变电磁法理论与应用研究.E-mail:ppxueguoqiang@163.com

中图分类号: P631

收稿日期:2017-01-05
修回日期:2017-09-01
上线日期:2018-01-05

Review of the key techniques on short-offset electromagnetic detection

HE JiShan^1,,
XUE GuoQiang^2,3,,
1. School of Geosciences and Info-Physics of Central South University, Changsha 410083, China
2. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
3. University of Chinese Academy of Sciences, Beijing 100049, China


More Information

Corresponding author: XUE GuoQiang,E-mail:ppxueguoqiang@163.com

MSC: P631

--> Received Date: 05 January 2017
Revised Date: 01 September 2017
Available Online: 05 January 2018


摘要
摘要:由于人工源电磁探测效果与收发距离有一定关系，本文首先分析了收发距离为零的中心回线源瞬变电磁法（Transient Electromagnetic Method，TEM）视电阻率定义和算法特点，回溯了从圆形回线到矩形的修正式中心回线装置的发展过程；概述了从中心回线发展到接地导线源短偏移瞬变电磁（Short-Offset TEM，SOTEM）理论上的可行性；列举了将LOTEM（Long-Offset TEM）从数倍于探测深度的观测区推进到近源区后的探测实例.对于频率域人工源电磁法，介绍了起源于MT（Magneto-Telluric）的CSAMT（Controlled Source Audio-frequency Magneto-Telluric）与电磁频率测深法不同发展道路.电磁频率测深将观测区从远区推进到了中区；广域电磁法通过全区视电阻率新定义不仅提高了解释精度，而且将传统CSAMT远场观测模式推进到中区探测模式；最后指出，如能采用新的点微元假设计算方法，可有望分离自有场和辐射场，实现频域电磁近源探测.
关键词: 近源电磁探测/
中心回线TEM/
短偏移SOTEM/
电磁频率测深/
广域电磁法

Abstract:Because the detecting effect of artificial-source electromagnetic methods is related to transceiver distance, taking the analysis expression and apparent resistivity algorithm as starting point, this paper reviews the development process from central-loop to modified central-loop TEM (Transient Electromagnetic Method), and summaries the principle of near-source prospecting from central-loop to grounded-wire source TEM. And the case history of SOTEM (Short-Offset TEM), which expands observation area of LOTEM (Long-Offset TEM) from several times of detection depth to near-source zone, is enumerated. For frequency-domain artificial-source electromagnetic methods, we present CSAMT (Controlled Source Audio-frequency Magnetotelluric) developed from MT (Magnetotelluric) and show the different way of frequency-domain electromagnetic sounding. Frequency sounding method enlarges the observation area from far-to middle-zone while the wide-field electromagnetic method improves interpretation accuracy and realize middle-zone data collection through whole zone apparent resistivity. If self-field and radiation field could be separated from each other based on the point-charge infinitesimal, frequency-domain near-source prospecting would be possible in the future.
Key words:Near-source electromagnetic prospecting/
Central-loop TEM/
Short-Offset TEM/
Frequency-domain sounding/
Wide field electromagnetic method



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