title: Crosswell electromagnetic modeling from impulsive source: Optimization strategy for dispersion suppression in convolutional perfectly matched layer.
abstract: This study applied the finite-difference time-domain (FDTD) method to forward modeling of the low-frequency crosswell electromagnetic (EM) method. Specifically, we implemented impulse sources and convolutional perfectly matched layer (CPML). In the process to strengthen CPML, we observed that some dispersion was induced by the real stretch κ, together with an angular variation of the phase velocity of the transverse electric plane wave; the conclusion was that this dispersion was positively related to the real stretch and was little affected by grid interval. To suppress the dispersion in the CPML, we first derived the analytical solution for the radiation field of the magneto-dipole impulse source in the time domain. Then, a numerical simulation of CPML absorption with high-frequency pulses qualitatively amplified the dispersion laws through wave field snapshots. A numerical simulation using low-frequency pulses suggested an optimal parameter strategy for CPML from the established criteria. Based on its physical nature, the CPML method of simply warping space-time was predicted to be a promising approach to achieve ideal absorption, although it was still difficult to entirely remove the dispersion.
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Sinan
authors: S
authors: Fang
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Heping
authors: H
authors: Pan
authors: Hubei coal geological survey institution, China National Administration of Coal Geology, Wuhan, China.
authors: Ting
authors: T
authors: Du
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Ahmed Amara
authors: AA
authors: Konaté
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Chengxiang
authors: C
authors: Deng
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Zhen
authors: Z
authors: Qin
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Bo
authors: B
authors: Guo
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Ling
authors: L
authors: Peng
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Huolin
authors: H
authors: Ma
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Gang
authors: G
authors: Li
authors: Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
authors: Feng
authors: F
authors: Zhou