3D direct inversion algorithm for electrical impedance underground anomaly detection with dual reciprocity boundary element modeling

Abstract

Anomaly detection is a technique to visualize the interior from the data measured on the ground surface for geophysical applications. The application can be used from oil field prospecting to land mine searching. We have developed the direct inversion algorithm for electrical impedance tomography based on dual reciprocity boundary element modeling, first for the two-dimensional field, which is here extended to three-dimensional field cases. The validation has been made for cases when impedance data are available for electrical current emanation diagonally injected to the surface surrounding the field of interest [Kagawa, Y., Sun, Y. and Zhao, Y., 1997, Direct inversion algorithm for electrical impedance tomography using dual reciprocity boundary element models. Inverse Problems in Engineering, 15, 217–237; Horikane, T., Hataya, T., Xu, W., Zhao, Y. and Kagawa, Y., 2002, 3D electrical impedance prospecting simulation based on dual reciprocity boundary element modelling. In: M. Tanaka and G.S. Dulikravich (Eds) Inverse Problems in Engineering Mechanics III (Amsterdam: Elsevier Science), pp. 411–418.] In practical prospecting, however, this is not always the case, as data are not always available for all surfaces. The present simulation includes the case of anomaly detection when the data are only available on the ground surface.