Sharp SCI: a new practical tool for blocky models reconstruction

In general, a priori information and assumptions are necessary to invert geophysical data. The problem is to formalize this knowledge in the appropriate way. The Sharp Spatially Constrained Inversion (sSCI) approach presented in this paper represents a contribution in this sense. Using the gradient support, it extracts from multilayer inversion the minimum number of-relatively homogeneous-resistivity domains needed to fit the AEM data, retrieving in this way their sharp boundaries. The sharp transitions are, to some extent, similar to those normally achieved with few-layer inversion-which however requires prior determination of the number of layers and may generate artefact in case of unexpected complex geologies. Results obtained from synthetic and experimental data illustrate the concept and prove that the sSCI can be superior to standard multilayer inversions in mapping sharp spatial resistivity transitions.