Numerical simulation of Electromagnetic Induction Responses of 2D structures as a tool to improve field data interpretation

MARTINELLI, PATRICIA; OSELLA, ANA; LASCANO, EUGENIA

2004 SEG Technical Program Expanded Abstract

SOCIETY OF EXPLORATION GEOPHYSICS

Año: 2004 vol. 23 p. 1456 - 1459

1052-3812

A Frequency-domain Electromagnetic Induction System was used to characterize an archaeological site in South Patagonia. This method involves the measurement of the change in mutual impedance between a pair of moving coils. These data are usually interpreted directly from the In-Phase and Quadrature components, and sometimes also by performing a 1D inversion. To improve the interpretation of data, we developed a forward code to calculate the response of  2D structures to a magnetic dipole source. This code is based  on the application of  the Rayleigh-Fourier technique. We performed numerical simulations of the In-Phase and Quadrature components of the response of buried structures. The conductivity and susceptibility of the bodies were varied and for each case we studied the characteristics of the responses for different orientations of the dipole source and receiver. We analyzed their corresponding sensitivity to determine which configuration best characterizes the structure, both laterally and in-depth. We also studied alternative ways of presenting the synthetic data to optimize the information that can be obtained before the application of 1D inversions. Finally, we applied our conclusions to analyze a set of  data obtained at the archaeological site.