## Realistic modeling of surface ground-penetrating radar antenna systems: where do we stand?

### Détails

ID Serval

serval:BIB_02E4945D2360

Type

**Article**: article d'un périodique ou d'un magazine.

Collection

Publications

Fonds

Titre

Realistic modeling of surface ground-penetrating radar antenna systems: where do we stand?

Périodique

Near Surface Geophysics

ISSN-L

1569-4445

Statut éditorial

Publié

Date de publication

2004

Peer-reviewed

Oui

Volume

2

Pages

15-23

Langue

anglais

Résumé

The generation and recording of electromagnetic waves by ground-penetrating

radar (GPR) systems are complex phenomena. To investigate the characteristics

of typical surface GPR antennae operating in realistic environments,

we have developed an antenna simulation tool based on a finite-difference

time-domain (FDTD) approximation of Maxwell's equations in 3D Cartesian

coordinates. The accuracy of the algorithm is validated with respect

to laboratory measurements for comparable antenna systems. Numerically

efficient and accurate modelling of small antenna structures and

high permittivity materials is achieved through a grid-refinement

procedure. We simulate the radiation characteristics of a wide range

of common surface GPR antenna types ranging from thin-wire antennae

to bow-tie antennae with arbitrary flare angles based on the assumption

of perfect electrical conductivity (PEC) of the metal parts. Due

to the modular structure of the algorithm, additional planar antenna

designs can readily be added. Shielding is achieved by placing a

metal box immediately above the antenna. To enhance the damping effects,

this metal box can be filled with a dielectric absorber and/or connected

to the antenna panels through discrete resistors. Finally, we also

consider the effects of continuous resistive loading of the antenna

panels using a sub-cell algorithm. We find that GPR antennae with

Wu?King-type resistivity profiles radiate compact, broadband pulses

and, as opposed to PEC antennae, are largely insensitive to their

operating environment. Unfortunately, these favourable radiation

characteristics are accompanied by a dramatic loss in radiation efficiency

compared to the corresponding PEC antennae.

radar (GPR) systems are complex phenomena. To investigate the characteristics

of typical surface GPR antennae operating in realistic environments,

we have developed an antenna simulation tool based on a finite-difference

time-domain (FDTD) approximation of Maxwell's equations in 3D Cartesian

coordinates. The accuracy of the algorithm is validated with respect

to laboratory measurements for comparable antenna systems. Numerically

efficient and accurate modelling of small antenna structures and

high permittivity materials is achieved through a grid-refinement

procedure. We simulate the radiation characteristics of a wide range

of common surface GPR antenna types ranging from thin-wire antennae

to bow-tie antennae with arbitrary flare angles based on the assumption

of perfect electrical conductivity (PEC) of the metal parts. Due

to the modular structure of the algorithm, additional planar antenna

designs can readily be added. Shielding is achieved by placing a

metal box immediately above the antenna. To enhance the damping effects,

this metal box can be filled with a dielectric absorber and/or connected

to the antenna panels through discrete resistors. Finally, we also

consider the effects of continuous resistive loading of the antenna

panels using a sub-cell algorithm. We find that GPR antennae with

Wu?King-type resistivity profiles radiate compact, broadband pulses

and, as opposed to PEC antennae, are largely insensitive to their

operating environment. Unfortunately, these favourable radiation

characteristics are accompanied by a dramatic loss in radiation efficiency

compared to the corresponding PEC antennae.

Création de la notice

25/11/2013 19:27

Dernière modification de la notice

18/11/2016 12:32