水平大定源回线瞬变电磁任意点一维正反演  

One-dimensional Forward and Inversion for an Arbitrary Point of Horizontal Large-loop Fixed Source Transient Electromagnetism

作　　者：石金晶 薛国强[1,2,3,4] 陈卫营 武欣[1,2,3] SHI Jin-jing;XUE Guo-qiang;CHEN Wei-ying;WU Xin(Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Innovation Academy of Earth Science,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Northwest Nonferrous Geology and Mining Group Co.,Ltd.,Xi'an 710054,Shaanxi,China)

机构地区：[1]中国科学院地质与地球物理研究所中国科学院矿产资源研究重点实验室,北京100029 [2]中国科学院地球科学研究院,北京100029 [3]中国科学院大学地球与行星科学学院,北京100049 [4]西北有色地质矿业集团有限公司,陕西西安710054

出　　处：《地球科学与环境学报》2022年第5期860-869,共10页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(42010306,41704076);中国科学院仪器设备研制项目(YJKYYQ20190004);第二次青藏高原综合科学考察研究专题(2019QZKK0804);自然资源部煤炭资源勘查与综合利用重点实验室开放项目(KF2020-3)。

摘　　要：大定源回线装置是瞬变电磁法(TEM)的一种工作装置,在框内外皆可进行观测,探测深度大、施工效率高。但受传统中心回线装置数据处理方式限制,当前大定源回线装置仅在发射线框中心一定区域内观测信号。基于电偶极子叠加方式,实现了发射线框内外任意位置电磁场的精确计算,并基于此分析了大定源回线装置产生的一次场和二次场的分布与扩散特征;随后利用OCCAM算法对发射线框内外任意点的响应进行一维反演,并通过一维层状模型对该方法的有效性进行了验证。结果表明,采用本文提出的正反演方法可以实现大定源回线装置发射线框内外任意点地下电性结构的准确反演。最后,将本文提出的正反演方法用于湖北省荆州市某机场的实测大定源回线装置实测数据处理中,取得了可靠的成果。Large-loop fixed source device is an equipment of transient electromagnetic method(TEM).It can be observed inside and outside the frame,with a large detection depth and high construction efficiency.However,limited by the traditional data processing method using the central loop device,the current large-loop fixed source device only observes the signal in a certain area in the center of the transmitting wireframe.Based on the superposition of electric dipoles,the accurate calculation of the electromagnetic field at arbitrary position inside and outside the transmitting frame was realized.Furthermore,the distribution and diffusion characteristics of the primary and secondary fields generated by the large-loop fixed source were analyzed.Then,the one-dimensional inversion of arbitrary point inside and outside the frame using the OCCAM algorithm was implemented,and the feasibility was verified by a layered model.The results show that the proposed method can accurately inverse the underground electrical structure at arbitrary point inside and outside the large-loop fixed source frame.Finally,the proposed method was applied to process the measured data from one airport in Jingzhou city of Hubei province,and the results are reliable.

关 键 词：瞬变电磁法 大定源回线装置 OCCAM算法 电偶极子合成 任意点 一维反演 

分 类 号：P319.32[天文地球—固体地球物理学] P631.3[天文地球—地球物理学]