物探与化探2024，Vol.48Issue(3)：721-735,15.DOI:10.11720/wtyht.2024.1395
CSRMT正交水平发射源电磁场分布规律研究
Distribution patterns of the electromagnetic fields of orthogonal horizontal magnetic dipoles as sources in CSRMT
摘要
Abstract
Controlled source radio-magnetotellurics(CSRMT)measurements typically use artificial field sources transmitting at fre-quencies ranging from 1 to 1 000 kHz.Among the many transmitting sources of the artificial source electromagnetic method,the orthog-onal horizontal electric dipole source and the orthogonal horizontal magnetic dipole source are preferred field sources for tensor resistivity measurements.Hence,using the analytical formulas for electromagnetic fields based on the horizontal electric dipole source and the horizontal magnetic dipole source,this study calculated the electromagnetic fields based on the orthogonal horizontal electric dipole source and the orthogonal horizontal magnetic dipole source in the homogeneous half-space model.The results show that:(1)The dis-placement current needs to be considered at transmitting frequencies above 100 kHz;(2)The effects of displacement current on the tensor apparent resistivity and the impedance phase can be ignored in the far zone;(3)With a constant model resistivity and varying distances between transmitter and receiver,model calculations indicate a larger measurement range in the far zone of the high-frequency electromagnetic field;(4)With a constant distance between transmitter and receiver and varying model resistivities,model calculations suggest that the far-zone range of the electromagnetic field is significantly influenced by resistivity,and that the high-resistivity model requires higher frequencies for achieving far-zone observation conditions.Compared with the electric dipole source,the magnetic dipole source exhibits smaller deviations on the tensor apparent resistivity and impedance phase with the actual value,which is more suitable for geological analysis.关键词
可控源射频大地电磁法/正交水平电偶源/正交水平磁偶源/位移电流/阻抗Key words
controlled source radio-magnetotellurics(CSRMT)/orthogonal horizontal electric dipole source/orthogonal horizontal magnetic dipole source/displacement current/impedance分类
天文与地球科学引用本文复制引用
陈兴朋,王亮,龙霞,席振铢,亓庆新,薛军平,戴云峰,胡子君..CSRMT正交水平发射源电磁场分布规律研究[J].物探与化探,2024,48(3):721-735,15.基金项目
国家重点研发计划课题(2022YFC2903404,2022YFC2900002) （2022YFC2903404,2022YFC2900002）
