Finite-element modeling of time-domain controlled-source electromagnetic survey with weighted Laguerre polynomials

Abstract

To facilitate the modeling of time-domain controlled-source electromagnetic surveys, we have developed an efficient finite-element method with weighted Laguerre polynomials, which indicates a much lower computational complexity than conventional time integration methods. Our method allows sampling the field at arbitrary time steps, and its accuracy is determined by the number of polynomials, instead of the time sampling interval. An analysis is performed regarding the optimization of the polynomial number to be used and the criterion of selecting the time scale factor. We conduct two numerical tests in marine and land survey environments to demonstrate the superiority of our method over the existing backward Euler time integration method. Our method is expected to facilitate the modeling of transient electromagnetic surveys in the geophysical regime.