A Triple-Grid Technique for the 3D Inversion of DC Resistivity Data Incoporating Arbitrary Topography

A024 A TRIPLE-GRID TECHNIQUE FOR THE 3D INVERSION OF DC RESISTIVITY DATA INCOPORATING ARBITRARY TOPOGRAPHY Summary 1 We present a novel technique for the determination of resistivity structures associated with arbitrary surface topography. The approach represents a triple-grid dc resistivty inversion technique which is based on unstructured tetrahedral meshes and a finite element forward operator applied to the secondary potential. We use a Gauss-Newton method with inexact line search to fit the data within error bounds. A global regularization scheme using special smoothness constraints is applied. The regularization parameter compromising data misfit and model roughness is determined by an L-curve