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THE TRANSIENT ELECTROMAGNETIC RESPONSE OF A POLARIZABLE SPHERE IN A CONDUCTING HALF SPACE 1
Author(s) -
LEE TERRY,
THOMAS LINDSAY
Publication year - 1992
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/j.1365-2478.1992.tb00540.x
Subject(s) - superposition principle , polarization (electrochemistry) , physics , polarizability , transient response , electromagnetic field , induced polarization , computation , classical mechanics , quantum mechanics , electrical resistivity and conductivity , mathematics , chemistry , electrical engineering , algorithm , molecule , engineering
A bstract A polarizable sphere embedded in a conducting half‐space can give rise to negative voltage transients in a coincident‐loop time‐domain electromagnetic system. Such transients have been observed in field situations. Our results are obtained from a model in which the contributions of the host rock, the currents in the sphere, and the interaction between the sphere and the host rock are separated and superposed. This model uses approximations to the integral equation solutions rather than finite‐element or finite‐difference approximations, and so allows very rapid computation. The theoretical demonstration suggests that interpretation of the negative voltage transients as a polarization response is valid, but more detailed interpretation of polarization properties may not be possible, because the superposition of the polarization response on the normal response depends strongly on the position of the target.