FUNDAMENTAL CHARACTBRISTICS OF ELECTROMAGNETIC COUPLING IN FREQUENCY-DOMAIN INDUCED POLARIZATION AND AN APPROXIMATE CORRECTION METHOD
Wang Jilun;Zhan Ke;Shen Lianjin;Yan Liguang (Geophysical Prospecting Co., Ministry of Metallurgical Industry)
Both gradient and dipole-dipole arrays may produce a rather strongelectromagnetic (EM) coupling effect under certain conditions. Variationsin these apparent effects are closely correlated with the changes ofsurface current density and also influenced by topographic relief. Thedipole-dipole array can provide EM coupling anomalies with the samesign and similar shape as true induced-polarization(IP) anomalies. The response curves of frequency effects of EM coupling in logarithmiccoordinates have distinctive features of sectional linearization.