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The detection of subsurface cracks and moisture in blast-holes is an important problem to be solved in open-cut coal mining. During the overburden removal process at open-cut coal mines, blast-holes are drilled and filled with ANFO explosive. Any explosive that extends into surrounding cracks within the blast-hole has the potential to remain unexploded during the detonation process, which results...
The interpretion of GPR data is usually limited by the attenuated signal and noise interference. The signal-to-noise ratio (SNR) of the received GPR data is influenced by the characteristics of GPR systems, the target signatures, the properties of the medium, and by incoherent random noise. The original attributes of the data will be distorted by noise. Usually, noise removal is conducted by employing...
In order to evaluate our developing 3D directional borehole radar system, ReflexTracker®, we carried out experimental studies on its capability to detect foundation piles in poor subsoil in the Tokyo area, and cavities beside a housing complex in Aichi Prefecture, central Japan. To evaluate foundation pile detectability, we took omnidirectional and directional borehole radar measurements in two boreholes...
Ultra-wideband (UWB) pulse generators based on an avalanche transistor are widely used in time domain ground penetrating radar(GPR). For shallow subsurface detection, it is essential to increase the pulse amplitude while maintaining the pulse width in order to improve the spatial resolution of GPR. Eliminating pulse trailing is also necessary to improve GPR performance. In this paper, a simple nanosecond...
This study is devoted to the electromagnetic (EM) characterization of concrete mixes within the ground penetrating radar frequency band. Defining two specific experimental designs, water and chloride contents are studied in order to establish their relative sensitivity compared to the other parameters describing the mixes. The evaluation of the complex dielectric properties is carried out in laboratory...
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...
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...
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...
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...
We apply integrated attribute analysis to extract more reliable quantitative information from processed GPR data, and obtain a better characterization of subsurface structures. A multi-attribute approach is used to characterize the subsurface through different attribute categories, including instantaneous, coherency, and textural attributes applied to quantities related not only to amplitude, phase,...
With the development of Ultra-Wideband (UWB) technology, UWB radar is widely used in disaster search and rescue operations and hostage rescue situations. Distinguishing between humans and animals is important during such searches. The aim of this paper is to study whether there are differences between humans and animals detected by UWB radar and whether these differences could be distinguished. In...
Polarimetric radar imaging is an emerging technology in ground penetrating radar (GPR). This paper presents a study of polarimetric radar imaging with single-input single-output (SISO) and multiple-input multiple-output (MIMO) configuration for GPR applications with a focus on infrastructure survey applications. To improve target characterization, we also perform the H-alpha analysis, which is one...
It has been well documented that the Sahara Desert experienced a number of humid periods during the late Quaternary, which resulted in the development of substantial lakes and fluvial networks. Today, the region is known for its hyper-arid conditions, with few isolated oases and no sizable surface drainage system. The remnants of these palaeochannels are now buried beneath the dunefields of the contemporary...
A theoretical method to relate the electrical relative permittivity (dielectric constant) and thermal conductivity of sands is presented. Extensive previous work has been done to relate the physical state (void ratio, water content, and saturation percent) of sandy soils to the bulk thermal conductivity and bulk relative permittivity respectively. These parameters have always been observed isolated...
This paper describes a system for non-destructive testing of radio transparent samples at microwaves. The main components of the system are a vector network analyzer (VNA), one or several stationary antennas connected to it, and a two-coordinate flat mechanical scanner that moves the sample in the antennas vicinity. The VNA and the scanner are controlled by a personal computer, which can acquire the...
The authors of this article investigated several issues concerning the testing of GPR surveying and the development of data processing methods for assisting in solving criminal activities as performed by the Investigative Committee of the Russian Federation. The work of governmental agencies along with forensic science are deeply based on using GPRs for detecting caches, crypts, conduits and saps,...
In this paper we cope with the problem of the evaluation of the propagation velocity of the electromagnetic waves in the soil from diffraction hyperbolas. In particular, some limits of the well known method of the diffraction hyperbolas are put into evidence and are partially overcome by means of a sequential migration algorithm, which provides a fast, easy, and reliable technique, not requiring separable...
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