 |
| Titel |
On the Analysis Methods for the Time Domain and Frequency Domain Response of a Buried Objects* |
| VerfasserIn |
Dragan Poljak, Silvestar Sesnic, Mario Cvetković |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091009
|
| Publikation (Nr.) |
 EGU/EGU2014-5274.pdf |
|
|
|
|
|
| Zusammenfassung |
| There has been a continuous interest in the analysis of ground-penetrating radar systems and
related applications in civil engineering [1]. Consequently, a deeper insight of scattering
phenomena occurring in a lossy half-space, as well as the development of sophisticated
numerical methods based on Finite Difference Time Domain (FDTD) method, Finite Element
Method (FEM), Boundary Element Method (BEM), Method of Moments (MoM) and various
hybrid methods, is required, e.g. [2], [3]. The present paper deals with certain techniques for
time and frequency domain analysis, respectively, of buried conducting and dielectric
objects.
Time domain analysis is related to the assessment of a transient response of a horizontal
straight thin wire buried in a lossy half-space using a rigorous antenna theory (AT)
approach. The AT approach is based on the space-time integral equation of the
Pocklington type (time domain electric field integral equation for thin wires). The
influence of the earth-air interface is taken into account via the simplified reflection
coefficient arising from the Modified Image Theory (MIT). The obtained results for the
transient current induced along the electrode due to the transmitted plane wave
excitation are compared to the numerical results calculated via an approximate
transmission line (TL) approach and the AT approach based on the space-frequency
variant of the Pocklington integro-differential approach, respectively. It is worth
noting that the space-frequency Pocklington equation is numerically solved via the
Galerkin-Bubnov variant of the Indirect Boundary Element Method (GB-IBEM) and
the corresponding transient response is obtained by the aid of inverse fast Fourier
transform (IFFT). The results calculated by means of different approaches agree
satisfactorily.
Frequency domain analysis is related to the assessment of frequency domain response of
dielectric sphere using the full wave model based on the set of coupled electric field
integral equations for surfaces. The numerical solution is carried out by means of
the improved variant of the Method of Moments (MoM) providing numerically
stable and an efficient procedure for the extraction of singularities arising in integral
expressions. The proposed analysis method is compared to the results obtained
by using some commercial software packages. A satisfactory agreement has been
achieved.
Both approaches discussed throughout this work and demonstrated on canonical
geometries could be also useful for benchmark purpose.
References
[1] L. Pajewski et al., Applications of Ground Penetrating Radar in Civil Engineering –
COST Action TU1208, 2013.
[2] U. Oguz, L. Gurel, Frequency Responses of Ground-Penetrating Radars Operating
Over Highly Lossy Grounds, IEEE Trans. Geosci. and Remote sensing, Vol. 40, No 6,
2002.
[3] D.Poljak, Advanced Modeling in Computational electromagnetic Compatibility, John
Wiley and Sons, New York 2007.
*This work benefited from networking activities carried out within the EU funded COST
Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar." |
|
|
|
|
|
|