Integral wave-migration method applied to electromagnetic data
- Sandia National Labs., Albuquerque, NM (United States)
Migration of the electromagnetic (EM) wave field will be discussed as a solution of the wave equation in which surface magnetic field measurements are the known boundary values. This approach is similar to classical optical diffraction theory. Here data is taken on a aperture, migrated (extrapolated), and deconvolved with a source function. The EM image is formed when the imaginary part of the Fourier transformed migrated field at time zero is zero or at least a minimum. The integral formulation for migration is applied to model data for surface magnetic fields calculated for a grounded, vertical electric source (VES). The conductivity structure is determined from comparing the measured migrated fields to calculated migrated fields for a yet to be determined conductivity structure. This comparison results in solving a Fredholm integral equation of the first kind for the conductivity structure. Solutions are obtained using the conjugate gradient method. The imaging method used here is similar to the EM holographic method reported earlier, except here the magnitudes, as well as the phases, of the extrapolated fields are preserved so that material properties can be determined.
- OSTI ID:
- 80229
- Report Number(s):
- CONF-941015-; TRN: IM9532%%356
- Resource Relation:
- Conference: 64. annual meeting of the Society of Exploration Geophysicists and international exposition, Los Angeles, CA (United States), 23-27 Oct 1994; Other Information: PBD: 1994; Related Information: Is Part Of SEG international exposition and sixty-fourth annual meeting -- 1994 Technical program: Expanded abstracts with authors` biographies; PB: 1736 p.
- Country of Publication:
- United States
- Language:
- English
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