title: Lagrangian and energy forms for retrieving the impulse response of the Earth due to random electromagnetic forcing.
abstract: We distinguish between trivial and nontrivial differences in retrieving the real or imaginary parts of the Green's function. Trivial differences come from different Green's function definitions. The energy and lagrangian forms constitute nontrivial differences. Magnetic noise sources suffice to extract the quasistatic electromagnetic-field Earth impulse response in the lagrangian form. This is of interest for Earth subsurface imaging. A numerical example demonstrates that all source vector components are necessary to extract a single-field vector component.
authors.affiliation: Department of Geotechnology, Delft University of Technology, Post Office Box 5048, NL-2600 GA Delft, The Netherlands. e.c.slob@tudelft.nl
authors.forename: Evert
authors.initials: E
authors.lastname: Slob
authors.forename: Chester J
authors.initials: CJ
authors.lastname: Weiss