3D general-measure inversion of crosswell EM data using a direct solver

Abstract We present a three-dimensional (3D) general-measure inversion scheme of crosswell electromagnetic (EM) data in the frequency domain with direct forward solver. In problem, we discretised EM Helmholtz equation by staggered-grid finite difference (SGFD) and solved it using Intel MKL PARDISO By applying solver, simultaneously multisource problems at given frequency. inversion, integrated general measure misfit model constraints linearised least-squares inversion. reconstructed blocky features selecting appropriate parameters constraints. used adjoint method to explicitly calculate Jacobian matrix, which facilitated determination an initial value for regularisation coefficient objective function. illustrated synthetic measure, L2 norm, and, specifically, two mixed norms.