Simulations of ground-penetrating radars over lossy and heterogeneous grounds

The versatility of the three-dimensional (3D) finite-difference time-domain (FDTD) method to model arbitrarily inhomogeneous geometries is exploited to simulate realistic ground-penetrating radar (GPR) scenarios for the purpose of assisting the subsequent designs of high-performance GPR hardware and software. The buried targets are modeled by conducting and dielectric prisms and disks. The ground model is implemented as lossy with surface roughness, and containing numerous inhomogeneities of arbitrary permittivities, conductivities, sizes, and locations. The impact of such an inhomogeneous ground model on the GPR signal is demonstrated. A simple detection algorithm is introduced and used to process these GPR signals. In addition to the transmitting and receiving antennas, the GPR unit is modeled with conducting and absorbing shield walls, which are employed to reduce the direct coupling to the receiver. Perfectly matched layer absorbing boundary condition is used for both simulating the physical absorbers inside the FDTD computational domain and terminating the lossy and layered background medium at the borders.

[1]  Levent Gurel,et al.  Modeling of ground-penetrating-radar antennas with shields and simulated absorbers , 2001 .

[2]  David J. Daniels,et al.  Surface-Penetrating Radar , 1996 .

[3]  Abinash C. Dubey,et al.  Detection and Remediation Technologies for Mines and Minelike Targets II , 1997 .

[4]  Levent Gürel,et al.  Three-dimensional FDTD modeling of a ground-penetrating radar , 2000, IEEE Trans. Geosci. Remote. Sens..

[5]  Jacques Citerne,et al.  AN extension of the PML technique to the fdtd analysis of multilayer planar circuits and antennas , 1995 .

[6]  U. Oguz,et al.  Employing PML absorbers in the design and simulation of ground penetrating radars , 1999, IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010).

[7]  Stephen D. Gedney,et al.  An Anisotropic PML Absorbing Media for the FDTD Simulation of Fields in Lossy and Dispersive Media , 1996 .

[8]  Allen Taflove,et al.  Finite-difference time-domain modeling of curved surfaces (EM scattering) , 1992 .

[9]  Glenn S. Smith,et al.  A fully three-dimensional simulation of a ground-penetrating radar: FDTD theory compared with experiment , 1996, IEEE Trans. Geosci. Remote. Sens..

[10]  Alan C. Tripp,et al.  Application and optimization of the perfectly matched layer boundary condition for geophysical simulations , 2000 .

[11]  Qing Huo Liu,et al.  Computation of transient electromagnetic waves in inhomogeneous media , 1991 .

[12]  Jean-Pierre Berenger,et al.  A perfectly matched layer for the absorption of electromagnetic waves , 1994 .

[13]  U. Oguz,et al.  Subsurface-scattering calculations via the 3D FDTD method employing PML ABC for layered media , 1997, IEEE Antennas and Propagation Society International Symposium 1997. Digest.

[14]  Weng Cho Chew,et al.  Finite-difference time-domain simulation of ground penetrating radar on dispersive, inhomogeneous, and conductive soils , 1998, IEEE Trans. Geosci. Remote. Sens..

[15]  K. Yee.  Numerical solution of initial boundary value problems involving maxwell's equations in isotropic media , 1966 .

[16]  Weng Cho Chew,et al.  A 3D perfectly matched medium from modified maxwell's equations with stretched coordinates , 1994 .

[17]  G. S. Smith,et al.  A complete electromagnetic simulation of the separated-aperture sensor for detecting buried land mines , 1998 .