HR: 1340h
AN: S53B-1269    [Abstracts]
TI: Deep Electromagnetic Imaging(EMI) Simulations for Realistic Heterogeneous Earth Models
AU: * Eyuboglu, S A
EM: eyuboglu.1@osu.edu
AF: School of Earth Sciences, The Ohio State University, Columbus, OH 43210, United States
AU: Daniels, J J
EM: daniels.9@osu.edu
AF: School of Earth Sciences, The Ohio State University, Columbus, OH 43210, United States
AU: Lee, R
EM: lee@ece.osu.edu
AF: ElectroScience Laboratory, Department of Electrical Engineering, The Ohio State University, Columbus, OH 43210, United States
AU: Yeh, J T
EM: ybiem@mac.hwr.arizona.edu
AF: Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721, United States
AB: Electromagnetic Imaging (EMI) is an extremely low frequency version of Ground Penetrating Radar (GPR) that provides deep non-invasive imaging of the subsurface. Recent breakthroughs in low frequency time-domain modeling show that reflections from frequencies in the very low megahertz range (center-band frequencies down to 500 kHz). Simulations of EMI data facilitate an understanding of the effects of complex electromagnetic phenomena in the intermediate frequency range (1-50 MHz) where both conduction and displacement currents affect wave propagation, as well as predicting the performance of radar antennas over a complex heterogeneous subsurface geologic environment. Our results show that specular reflections from objects buried down to a depth of 15-20 m in a heterogeneous environment can be imaged using a robust finite difference time domain algorithm (FDTD) with a source pulse center-band frequency lower than 1 MHz. A highly efficient robust algorithm was developed to enhance the effectiveness of the simulation in surroundings characterized by an arbitrary distribution of all electromagnetic properties (conductivity, permittivity, and permeability). The modeling is facilitated by a graphical algorithm that enables a detailed simulation of each component of the system, including a heterogeneous half-space and the physical details of the transmitter and receiver antennas. In terms of specific targets, the results produced by the simulation demonstrated the applicability of low frequency GPR for detecting cavities in heterogeneous environment down to depths of 20 m using 500 KHz center-band source pulse.
DE: 0619 Electromagnetic theory
DE: 0634 Measurement and standards
DE: 0659 Random media and rough surfaces
SC: Seismology [S]
MN: 2007 Fall Meeting