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| Titel |
Electromagnetic modelling, inversion and data-processing techniques for GPR: ongoing activities in Working Group 3 of COST Action TU1208 |
| VerfasserIn |
Lara Pajewski, Antonis Giannopoulos, Jan van der Kruk |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111792
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| Publikation (Nr.) |
 EGU/EGU2015-14988.pdf |
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| Zusammenfassung |
| This work aims at presenting the ongoing research activities carried out in Working Group 3
(WG3) “EM methods for near-field scattering problems by buried structures; data
processing techniques” of the COST (European COoperation in Science and Technology)
Action TU1208 “Civil Engineering Applications of Ground Penetrating Radar”
(www.GPRadar.eu).
The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical
knowledge and experience of GPR techniques in civil engineering, simultaneously promoting
throughout Europe the effective use of this safe and non-destructive technique in the
monitoring of infrastructures and structures.
WG3 is structured in four Projects. Project 3.1 deals with “Electromagnetic modelling for
GPR applications.” Project 3.2 is concerned with “Inversion and imaging techniques for GPR
applications.” The topic of Project 3.3 is the “Development of intrinsic models for describing
near-field antenna effects, including antenna-medium coupling, for improved radar
data processing using full-wave inversion.” Project 3.4 focuses on “Advanced GPR
data-processing algorithms.”
Electromagnetic modeling tools that are being developed and improved include the
Finite-Difference Time-Domain (FDTD) technique and the spectral domain Cylindrical-Wave
Approach (CWA). One of the well-known freeware and versatile FDTD simulators is
GprMax that enables an improved realistic representation of the soil/material hosting
the sought structures and of the GPR antennas. Here, input/output tools are being
developed to ease the definition of scenarios and the visualisation of numerical results.
The CWA expresses the field scattered by subsurface two-dimensional targets with
arbitrary cross-section as a sum of cylindrical waves. In this way, the interaction
is taken into account of multiple scattered fields within the medium hosting the
sought targets. Recently, the method has been extended to deal with through-the-wall
scenarios.
One of the inversion techniques currently being improved is Full-Waveform Inversion (FWI)
for on-ground, off-ground, and crosshole GPR configurations. In contrast to conventional
inversion tools which are often based on approximations and use only part of the available
data, FWI uses the complete measured data and detailed modeling tools to obtain an
improved estimation of medium properties.
During the first year of the Action, information was collected and shared about
state-of-the-art of the available modelling, imaging, inversion, and data-processing methods.
Advancements achieved by WG3 Members were presented during the TU1208
Second General Meeting (April 30 – May 2, 2014, Vienna, Austria) and the 15th
International Conference on Ground Penetrating Radar (June 30 – July 4, 2014, Brussels,
Belgium).
Currently, a database of numerical and experimental GPR responses from natural and
manmade structures is being designed. A geometrical and physical description of the
scenarios, together with the available synthetic and experimental data, will be at the disposal
of the scientific community. Researchers will thus have a further opportunity of testing and
validating, against reliable data, their electromagnetic forward- and inverse-scattering
techniques, imaging methods and data-processing algorithms. The motivation to start this
database came out during TU1208 meetings and takes inspiration by successful past
initiatives carried out in different areas, as the Ipswich and Fresnel databases in the field
of free-space electromagnetic scattering, and the Marmousi database in seismic
science.
Acknowledgement
The Authors thank COST, for funding the Action TU1208 “Civil Engineering Applications of
Ground Penetrating Radar.” |
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