Properties of surface waveguides derived from separate and joint inversion of dispersive TE and TM GPR data

Pronounced dispersion of ground-penetrating radar (GPR) waves is observed at locations distinguished by thin surface layers of high-permittivity material (e.g., water-saturated soil). The dispersion characteristics depend on the permittivity and thickness of the effective surface waveguide and the permittivity of the material below it. We introduce a scheme for estimating the values of these parameters from dispersed transverse-electric (TE) and transverse-magnetic (TM) GPR data that is analogous to recently developed methods for analyzing dispersed Rayleigh waves recorded on multichannel seismic data. Our scheme involves calculating phase-velocity spectra, picking dispersion curves from the spectra, and then inverting the dispersion curves for the subsurface material properties by using a combined local- and global-minimization procedure. Application of this new scheme to synthetic and field data demonstrates its efficacy in providing the required physical property information. Where the surface layer is relatively distinct and uniform, inversions of the resulting high-quality dispersed TE data provide all required parameters. In more heterogeneous environments, joint inversions of the TE and TM data, which usually include information in different frequency ranges, may be required.

[1]  Michael Roth,et al.  Inversion of source‐generated noise in high‐resolution seismic data , 1999 .

[2]  A. Green,et al.  A finite-difference time-domain simulation tool for ground-penetrating radar antennas , 2003 .

[3]  Jianghai Xia,et al.  Estimation of near‐surface shear‐wave velocity by inversion of Rayleigh waves , 1999 .

[4]  D. Schmitt,et al.  Simulated annealing inversion of multimode Rayleigh wave dispersion curves for geological structure , 2002 .

[5]  Evert C. Slob,et al.  Effective source wavelet determination , 2002, International Conference on Ground Penetrating Radar.

[6]  Jianghai Xia,et al.  Determining Q of near-surface materials from Rayleigh waves , 2002 .

[7]  Steven A. Arcone,et al.  Propagation of a ground-penetrating radar (GPR) pulse in a thin-surface waveguide , 2003 .

[8]  R. D. Watts,et al.  THE ELECTROMAGNETIC RESPONSE OF A LOW‐LOSS, 2‐LAYER, DIELECTRIC EARTH FOR HORIZONTAL ELECTRIC DIPOLE EXCITATION , 1975 .

[9]  P. M. van den Berg,et al.  Three-dimensional imaging of multicomponent ground-penetrating radar data , 2003 .

[10]  Jeffrey C. Lagarias,et al.  Convergence Properties of the Nelder-Mead Simplex Method in Low Dimensions , 1998, SIAM J. Optim..

[11]  Richard D. Miller,et al.  Multichannel analysis of surface waves , 1999 .

[12]  Lanbo Liu,et al.  Numerical Simulation of the Wave-Guide Effect of the Near-Surface Thin Layer on Radar Wave Propagation , 2003 .

[13]  Steven A. Arcone,et al.  Field observations of electromagnetic pulse propagation in dielectric slabs , 1984 .

[14]  Jianghai Xia,et al.  Imaging dispersion curves of surface waves on multi-channel record , 1998 .

[15]  Thomas Forbriger,et al.  Inversion of shallow-seismic wavefields: II. Inferring subsurface properties from wavefield transforms , 2003 .

[16]  Frank Scherbaum,et al.  Determination of shallow shear wave velocity profiles in the Cologne, Germany area using ambient vibrations , 2003 .

[17]  R. Dai,et al.  Transient fields of a horizontal electric dipole on a multilayered dielectric medium , 1997 .

[18]  K. G. Budden.  The Wave-guide mode theory of wave propagation , 1963 .

[19]  Glenn S. Smith.  Directive properties of antennas for transmission into a material half-space , 1984 .

[20]  Roel Snieder,et al.  IN SITU MEASUREMENTS OF SHEAR‐WAVE VELOCITY IN SEDIMENTS WITH HIGHER‐MODE RAYLEIGH WAVES* , 1987 .

[21]  Thomas Forbriger,et al.  Inversion of shallow-seismic wavefields: I. Wavefield transformation , 2003 .

[22]  Jianghai Xia,et al.  Inversion of high frequency surface waves with fundamental and higher modes , 2003 .

[23]  Jianghai Xia,et al.  Utilization of high-frequency Rayleigh waves in near-surface geophysics , 2004 .

[24]  A. P. Annan,et al.  Radio Interferometry Depth Sounding: Part I—THEORETICAL Discussion , 1973 .

[25]  Jan van der Kruk,et al.  Three-dimensional imaging of multi-component ground penetrating radar data , 2001 .