Simultaneous reconstruction of 1-D susceptibility and conductivity from electromagnetic data

In this paper, we develop an inversion algorithm to simultaneously recover l-D distributions of electric conductivity and magnetic susceptibility from a single data set. The earth is modeled as a series of homogeneous layers of known thickness with constant but unknown conductivities and susceptibil ities. The medium of interest is illuminated by a horizontal circular loop source located above the surface of the earth, The secondary signals from t he earth are received by a circular loop receiver located some distance fro m the source. The model objective function in the inversion, which we refer to as the cost function, is a weighted sum of model objective functions of conductivity and susceptibility. We minimize this cost function subject to the data constraints and show how the choice of weights for the model obje ctive functions of conductivity and susceptibility affects the results of t he inversion through l-D synthetic examples. We also invert 3-D synthetic a nd field data. From these examples we conclude that simultaneous inversion of electromagnetic (EM) data can provide useful information about the condu ctivity and susceptibility distributions.