用瞬变激发阵列电极探测低阻异常体实验研究  

Experimental study on detecting low resistance anomalies with transient excitation array electrode

作　　者：沈建国 钱冬冬 沈永进 陈赟 SHEN Jian-guo;QIAN Dong-dong;SHEN Yong-jin;CHEN Yun(School of Microelectronics,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学微电子学院,天津300072

出　　处：《地球物理学进展》2020年第5期1969-1977,共9页Progress in Geophysics

基　　金：国家重点研发计划(2016YFC0802000)资助.

摘　　要：通过控制激发电流的导通/关断,置于水中的线状电极在空间中既能激发出瞬变电磁场,又能够激发稳定电流场.用平面阵列电极可以接收到这两种电磁场的全波波形,进而通过对数据计算处理,得到瞬变电场和稳定电场的在平面上的二维电位分布.本文首先分析了采集到的原始全波波形,发现在导通和关断瞬间有极大值存在,并用理论计算、模拟瞬变电磁场的传播特性.然后对比研究了瞬态响应和稳态响应的变化规律,利用有限差分迭代方法,计算了有、无异常体以及异常体不同深度情况下的电位等高线图.进一步对数据进行分析,选择实验测量波形中不同时刻的电位数据,绘制了瞬态响应和稳态响应的电位等高线图,并通过做差的方法在电位等高线中直接体现异常体的位置.数值仿真和实验测量的结果对比表明,因低阻体的存在而引起的电位畸变可以通过实验测得,这为实际应用提供了参考标准.By controlling the on/off of the excitation current,the linear electrode placed in water can excite both transient electromagnetic field and stable current field in space.The full-wave waveforms of the two electromagnetic fields can be obtained by using planar array electrodes,and the potential distribution of the transient electric field and the stable electric field on the plane can be obtained.Firstly,the original waveform of measurement is analyzed,It is found that there are maxima at the moment of on and off,and the propagation characteristics of transient electromagnetic field are simulated by theory.and the changing rules of transient response and steady-state response are studied.Secondly,the finite difference iteration method is used to calculate the contour maps of body time potentials with and without abnormal-ities.Then,the potential contours of transient response and steady-state response are plotted by choosing the potential data at different time in the measured waveform.Finally,through data processing,it is found that the transient waveform of electromagnetic response carries water medium information.And the position of the abnormal body is directly reflected in the contour line by making a difference.The comparison between the results of numerical simulation and experimental measurements shows that the potential distortion caused by the presence of low resistors can be measured by experiments,which provides a reference standard for practical application.

关 键 词：阵列电极 低阻异常体 线源 电位等高线 稳定电流场 

分 类 号：P631[天文地球—地质矿产勘探]