Three-dimensional Inversion of Helicopter-borne Electromagnetic Data Using the Spectral Lanczos Decomposition Method

In this paper we develop a new method of interpretation of the helicopter-borne electromagnetic (HEM) data over inhomogeneous geolitical structures, typical for mining exploration. We apply the spectral Lancoz decompostition method (SLDM) in the framework of the localized quasi-linear inversion introduced by Zhadanov and Tartaras (2002). This technique helps to accelerate HEM data inversion and provides a stable and foclused image of geoelectical target. The new method and the corresponding computer code has been tested on synthetic data. We apply this technique for interpretation of the helicopter-borne data collected by INCO Exploration in the Voisey''s Bay area of Canada.