接地导线间的电磁耦合引起电阻率随频率变化,因此,不论是在频率域还是在时间域的激发极化测量中,它都是产生假异常的主要来源.对野外所遇到的电磁耦合影响作精确的定量估计,往往是很困难的.然而,在简单情况(例如均匀半空间,或两层大地)下,对电磁耦合作出的估计将有助于正确解释激发极化异常. 按Sunde的理论,Madden和Cantwell曾讨论了在均匀半空间用偶极-偶极和施伦贝尔热(即不等距对称四极)几何排列作频率域测量时的电磁耦合影响.Millet计算了 Electromagnetic coupling between the ground leads to resistivity changes with frequency, so it is the main source of false anomalies in the frequency domain or in the time domain of the excitation polarization measurements.The electromagnetic coupling effects encountered in the field However, in simple cases (such as homogeneous half-space, or two-layer earth), the estimation of the electromagnetic coupling will help to correctly interpret the excitation polarization anomalies. According to Sunde’s Theory, Madden and Cantwell discussed the effect of electromagnetic coupling in frequency domain measurements using dipole-dipole and Schlumberger thermal (ie unequally symmetric quadrupole) geometrical arrangements in a homogeneous half-space. Millet calculated