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Ground penetrating radar (GPR) has been employed as an effective means for mapping features buried in the ground or in man-made structures for several decades. The content of a typical GPR reflection profile is graphically displayed showing the signal amplitude versus space and time after signal emission. The position and travel time information of features are then used to characterize target spatial...
The use of tack coats in the construction of road structures is a technique that ensures pavement layer bonding. Unfortunately, existing techniques commonly used in France to study tack coats require coring of structures for a punctual characterization in a laboratory. This paper presents an innovative non-destructive approach to characterize the change of geometric and dielectric properties of the...
We apply an automated picking and inversion algorithm to ground-based and airborne glaciological GPR surveys, in order to recover the internal stratigraphy, density distribution, and water content of alpine glaciers. Current glacier monitoring techniques encompass topographic mapping, direct measurements, and GPR surveys. However, the resulting models strongly depend on the assumptions made about...
This article illustrates the experience of using GPR in areas of gold deposits at the Allah-Yun and Bolshoy Kuranah River (Yakutia, Russia). We considered the methodical base of dredge site GPR in the permafrost zone. The studies identified and mapped rocky outcrops and areas of boulder encrusting matter and also defined the geometry and areas of bedding rock fracturing. A method of GPR mapping of...
This paper focuses on the development of the new holographic subsurface radar data acquisition technique in which the position and the polarization of the microwave probe are established by its tracking with video. This technique allows adaptive interactive data acquisition when probe trajectory could not be predefined or be equally dense in the areas with no target. The data processing technique...
A validation study was conducted over a fixed alignment of underground utilities to study the effects of GPR traverse directions on GPR wave velocity estimation of utilities. The experiment was carried out on a 0.98 m deep underground drainage pipe in the campus of Hong Kong PolyU. During the changes of GPR traverse directions relative to the fixed and known utility alignments at an angle 90°, 75°,...
Simulation of electromagnetic wave propagation in lossy and dispersive media requires a realistic description of the electrical and dielectric media parameters. We measured the complex dielectric permittivity of fine sand and silty clay in the GPR frequency range using the coaxial transmission line technique. We inverted the data with single- and multi-pole Debye models and a constant dc conductivity...
Lunar penetrating radar (LPR) is an important way to carry out lunar probing. The detection result of Rabbit lunar radar carried by Chang'E 3 provides a reliable scientific foundation for studying the underground structure and depth distribution of the moon. The regolith modeling and numerical simulation can provide a reliable reference for lunar detection and data interpretation. In this abstract,...
In recent years, there has been a surge of new applications of composite materials and structures in aerospace industry. The composites have many advantages over traditional metal alloys. They have, as a rule, better strength/weight ratio, withstand to unfavorable weather conditions and aggressive environments. Corrosion also doesn't affect them. Traditional methods of ultrasonic diagnostics are ineffective...
Optical remote sensing data provide an effective way of mapping snow cover but limited by solar illumination conditions, whereas polarimetric decomposition technology offers the ability to monitor snow cover in all weathers. In the present study, a support vector machine (SVM) method for extracting snow cover based on RadarSat-2 Polarimetric SAR data in rugged mountain terrain is introduced. In this...
Ground Penetrating Radar (GPR) investigations were conducted in order to characterize the reflection patterns and internal architecture of Vistula River point bars. The study area is situated in the south part of Warsaw (Central Poland), in the Nature Reserve Świderskie Islands, where fluvial deposits were well accessible due to an unusually low water level in the Vistula River. Ground Penetrating...
Several data fusion approaches have been developed to maximize both resolution and characterization depth for GPR. In this study, we propose a new physically-based method to merge multi-frequency radar data coming from different antennas. The strategy relies on the removal of antenna effects and the subsequent fusion of the resulting Green's functions in the frequency domain. We validated the approach...
A GPR system is composed of a transmitter and a receiver antenna placed on the ground surface. The exciting current injected into the transmitter antenna is, in general, unknown. Its knowledge is of great importance in the GPR modeling in time or frequency. In the following analysis we, firstly, identify different types of GPR waves for two parallel dipole antennas located on the ground in a common...
Much work, some quite complex, has been expended on experiments and modelling for imaging voids using ground penetrating radar (GPR). However, much can be learned from simple models. For example, a simple Ricker wavelet model can be used to illustrate some fundamental properties of the GPR response from voids, both air- and water-filled. In particular, reflections from the top and the bottom of a...
This paper describes an array antenna system for lunar regolith penetrating radar (LRPR), which is an important payload onboard the lander of Chang'E-5. The array's proposed operational frequency range is from 1000MHz ∼ 3000MHz. It has 12 elements arrayed along their H plane. The elements are designed into a compact Vivaldi antenna with 1/4 elliptical slot in order to realize the need for ultra-wideband,...
In order to design holographic and impulse GPRs, as well as metal detector (MD) sensors for humanitarian demining in the Donbass conflict zone, we have compiled a listing of the AP and AT mines that have been confirmed in use in Donbass, and their dimensions and construction. Just as importantly, we have attempted, from existing literature (since it is an active war zone), to characterize the specific...
Time-frequency spectral responses of an in-house built step-frequency continuous wave (SFCW) GPR (Y akumo) developed by Tohoku University and a commercial impulse GPR were studied and compared. The Yakumo SFCW GPR operates from 50 MHz to 1.5 GHz, and the center frequency of the commercial impulse GPR is 500 MHz. Both GPRs were probed on top of an embedded steel pipe overlaid by a concrete pavement...
Limestone is a widely used building material. Its degradation process is strongly linked to the water content, to which the radar waves are sensitive. In this paper, a model of stepped-frequency radar (SFR) wave propagation through partially wet limestone is proposed, in order to study the water transfer front in limestone. We assume the limestone as a two-layer (dry/wet) lossy medium and use an analytical...
In recent years, the shield tunneling method has been widely used in the construction of urban underground space. Through using ground penetrating radar (GPR) for nondestructive testing of the distribution of grouting behind segments of shield tunnel, secondary compensatory grouting can be carried out, which is aimed at controlling the final longitudinal settlement of the tunnel. In this paper, the...
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