CSAMT测量中磁场对测量结果的影响  

The influence of magnetic field on measuring result of CSAMT

作　　者：王珺璐[1] 林品荣[1] 李荡[1] 李建华[1] 王萌[2] 

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [2]中国国土资源航空物探遥感中心,北京100083

出　　处：《煤田地质与勘探》2015年第6期100-104,108,共6页Coal Geology & Exploration

基　　金：国家重大科学仪器设备开发专项(2011YQ050060);国家高技术研究发展计划(863计划)项目(2014AA06A610);中国地质大调查(12120113031700;12120113101500);中央级公益性科研院所基本科研业务费项目(AS2014D01)

摘　　要：CSAMT的标量测量中常采用共磁道测量方式,即同步观测测量剖面上多个电道信号和垂直测量剖面的一个磁道信号,由此计算各测点的Cagniard视电阻率。因磁场测量位置的不同,势必对测量结果产生影响。计算了均匀半空间条件下不同测量位置的磁场强度,以及对视电阻率的影响;模拟了存在局部三维异常体时,赤道装置下不同位置的磁场对视电阻率的影响。结合野外实测资料分析认为,由磁场测量位置偏差引起的视电阻率误差难以校正,在实际工作中应尽量采用单电单磁的测量方式;当在大收发距且浅层电性结构单一的条件下,可以采用三电一磁的测量方式。研究对CSAMT标量测量方式的改进及实际勘查工作具有一定的指导意义。The common track measurement is often used in scalar measurement of CSAMT. That is using electrical signals of the measurement of synchronous observation profile and a track signal of the vertical measurement to calculate the Cagniard apparent resistivity. For the different measurement position of magnetic field, there is impact on the measurement results. This paper deals with the influence of the different position of magnetic field on ap-parent resistivity measurement under homogeneous half space, and the influence of the different position of the equatorial magnetic field on apparent resistivity when the 3-D local anomalous body is excited. The apparent resis-tivity error caused by measuring position deviation of magnetic field is difficult to be corrected. Therefore, single magnetic single power measurement should be used in practical work, and single magnetic three powers should be used when the transceiver distance is large or the shallow electrical structure is uniform. It has important guiding significance for the research on scalar measurement of CSAMT and practical exploration work.

关 键 词：可控源电磁法 磁场 Cagniard视电阻率 误差 

分 类 号：P631[天文地球—地质矿产勘探]