Numerical Analysis of the Detection Performance
of Ground Coupled Radars
for Different Antenna Systems and Signal Features
Davide Comite1, Alessandro Galli1, Elena Pettinelli2, and Guido Valerio3
Department of Information Engineering, Electronics and Telecommunications (DIET)
“Sapienza” University of Rome, Via Eudossiana 18, 00184 Rome, Italy
e-mail: {comite, galli}@diet.uniroma1.it 2
Department of Mathematics and Physics
“Roma Tre” University, Via della Vasca Navale 84, 00146 Rome, Italy
e-mail: pettinelli@fis.uniroma3.it
3
Institut d’Electronique et de Télécommunications de Rennes (IETR) Université de Rennes 1, Avenue du Général Leclerc, 35042 Rennes, France
e-mail: guido.valerio@univ-rennes1.fr
These specific issues are investigated in this context Abstract—The detection capabilities of ground penetrating
radar (GPR) for shallow subsurface investigations is primarily through ad-hoc analyses using a customized numerical setup related to the efficient design of the antennas and to the [5], based on a time-domain commercial CAD tool (CST suitable choice of the signal waveforms. An exploration of such
Microwave Studio) [6].
aspects is the subject of the present work, with specific interest
Thanks to the relevant advantages of the numerical to ground-coupled monostatic and bistatic configurations. In
implementation as regards economy and flexibility, a order to address in a consistent way the issues related to the
variety of simulations of GPR systems has specifically been influence of the type of antennas and of the transmitted signal
traces, extensive analyses have been performed numerically, carried out for testing different GPR antenna configurations based on ad-hoc implementation of a full-wave electromagnetic and signal features (in terms of waveforms and spectra), CAD tool. The relevant effects on the reconstruction of radar referring to typical scenarios of practical interest (such as sections are evaluated and discussed in a number of test cases
those involving GPR shallow-subsurface investigations for
for the detection of buried scatterers in scenarios of practical
planned planetary missions) [5,7-9]. interest.
To this aim, a number of different topologies of GPR
Index Terms—Ground Penetrating Radar (GPR), antenna antennas are designed and implemented, analyzing system, signal waveforms, shallow subsurface, detection of
numerically their features in terms of matching with the
buried scatterers.
external environment, bandwidth, and field distributions (both in far-field and in near-field conditions). The desirable
I. INTRODUCTION effects related to wide-band radiators are particularly
In a wide variety of geophysical, civil, and space emphasized in connection with different waveforms that can applications, the capability of properly detecting and be chosen for the GPR transmitted signal. locating ‘buried targets’ is a topic of great scientific interest. Compared quantitative analyses are thus possible for the For these purposes, different types of ground penetrating study of the scattering effects due to buried targets in radar (GPR) systems are commonly used in monostatic and various practical conditions. This allows us, for instance, to bistatic ground-coupled configurations [1,2]. test the detection performance of targets with dimensions Broadly speaking, the achievement of qualitatively valid comparable to the typical signal wavelengths and buried ‘direct’ data on the scattering effects of targets by means of very close to the interface where the ground-coupled GPR is primarily dependent on the antenna features and on antenna systems can operate. Relevant results on the the signal waveforms chosen, in addition to the scenario-scattering of targets are presented and discussed in the frame
related aspects (such as the geometry of the target and its of useful GPR applications. electromagnetic contrast with background, the possible
II. DESIGN AND TEST OF GPR ANTENNAS attenuation and dispersion in the media, the presence of
inhomogeneities, etc.). Based on the availability of the A versatile numerical implementation of a ground-direct scattering data, it is then possible to apply the most coupled system, based on CST Microwave Studio, has appropriate and efficient inversion procedures for the allowed us to efficiently design and test different types of correct detection of the buried targets [1-4]. GPR configurations.
1
The typical simulated scenario of investigation considers an inhomogeneous region basically consisting of two different media (e.g., an air/ground environment), in which arbitrary scatterers can be located and detected through monostatic or bistatic interfacial antenna systems, as sketched in Fig. 1.
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