Effects of magnetite on high-frequency ground-penetrating radar

Dam, Remke L. Van; Hendrickx, Jan M. H.; Cassidy, Nigel J.; North, Ryan E.; Doğan, Mine; Borchers, Brian

doi:10.1190/geo2012-0266.1

Cited by 16 publications

(11 citation statements)

References 42 publications

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“…(23), (24), (25) and (26), respectively, and shown in Tables 3 and 4. The measured results are also compared with standard Tables 3 and 4, the results of complex permittivity and permeability measurement using the proposed sensor are analogous with the standard values available in the literature [38][39][40][41][42][43]. Measurements of the real part and tangent loss of permeability and permittivity are possible with Frequency(GHz) typical error between the range of 2%-5%.…”

Section: Measurement and Resultsmentioning

confidence: 83%

Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

Porwal¹,

Azeemuddin²,

Bhimalapuram³

et al. 2017

PIER C

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Abstract-In this paper, a novel microwave planar resonant sensor is designed and developed for simultaneous detection of permittivity and permeability of an unknown sample using a nondestructive technique. It takes advantage of two-pole filter topology where the interdigitated capacitor (IDC) and spiral inductor are used for placement of a sample with significant relative permittivity and permeability values. The developed sensor model has the potential for differentiating permittivity and permeability based on the odd mode and even mode resonant frequencies. It operates in the ISM (industrial, scientific and medical) frequency band of 2.2-2.8 GHz. The sensor is designed using the full wave electromagnetic solver, HFSS 13.0, and an empirical model is developed for the accurate calculation of complex permittivity and permeability of an unknown sample in terms of shifts in the resonant frequencies and transmission coefficients (S 21 ) under loaded condition. The designed resonant sensor of size 44×24 mm 2 is fabricated on a 1.6 mm FR4 substrate and tested, and corresponding numerical model is experimentally verified for various samples (e.g., magnetite, soft cobalt steel (SAE 1018), ferrite core, rubber, plastic and wood). Experimentally, it is found that complex permeability and permittivity measurement is possible with an average error of 2%.

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Section: Measurement and Resultsmentioning

confidence: 83%

Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

Porwal¹,

Azeemuddin²,

Bhimalapuram³

et al. 2017

PIER C

View full text Add to dashboard Cite

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“…Therefore, the resulting waveform indicates the amplitude of energy scattered from subsurface materials (Koppenjan ). The depth range of the GPR technique largely depends on the centre frequency of the antenna used, as well as the dielectric properties, electrical conductivity, and magnetic permeability of the medium investigated (Olhoeft ; Annan ; Cassidy ; Van Dam et al ). The penetration depth of radar signals decreases with increasing electrical conductivity, magnetic permeability, and dielectric characteristics of subsurface materials, and the energy of the radar signal is more rapidly scattered due to the transformation of heat energy (Shari, Millard, and Bungey ; Annan ).…”

Section: Fundamentals Of Ground‐penetrating Radar Surveyingmentioning

confidence: 99%

Applications of the GPR Technique to indoor, bridge deck and pier structures: case studies in Turkey

Drahor

Öztürk²,

Ongar

et al. 2015

Near Surface Geophysics

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This paper presents the results of three ground-penetrating radar case studies applied to indoor, bridge deck, and pier construction types in Turkey. In these studies, 270-MHz and 1600-MHz antennas were employed to determine the ability limits for construction materials and diagnostic problems associated with the materials. In addition, the importance of the selected survey direction was tested during measurement. Analysing the significance of the migration technique during the data processing stage was another important goal of these case studies. The first case study analyses the indoor applications (e.g., house, villa, and fabric) of ground-penetrating radar and aims to identify possible cracks, structural defects, and corrosion damage. The second case applies ground-penetrating radar to a bridge deck. The third case investigates pier construction by establishing the layout of the construction materials. Identifying possible defects, including structural problems within the pier structure, was another goal. These case studies provide interesting results in terms of physically characterizing the concrete structure and the locations of rebar and slab conditions; the work also reveals the moisture and corrosion effects inside the construction materials on indoor, bridge and pier applications of ground-penetrating radar.in civil engineering. Therefore, large volumes of oxidized zones inside the materials might cause significant damage through the effects of cracking and debonding. Consequently, the most critical problems and important deterioration effects may develop on bridges and pier decks. The corrosion of steel inside the reinforcement is mostly subjected to chloride ion exposure, moisture, and various iron oxides (FeO, Fe 2 O 3 , Fe 3 O 4 and others). In fact, this process, clearly defined by Neville and Brooks (1987), progresses rapidly in irons. This phase can result in debonding between steel and concrete due to water infiltration (Hubbard et al. 2003), delamination of the concrete cover material from the reinforcement, and cracking (Benedetto 2013). GPR is an important method in diagnosing progressive corrosion problems before damage. The visibility of GPR in non-destructive applications depends on the relevant electromagnetic contrast between the dielectric characteristics of uncorrupted and oxidized materials, which result from moisture among the steel and concrete materials (Halabe, Maser, and

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“…Mineralogical and geochemical changes in composition can strongly affect the GPR effectiveness in the sense of the penetration of electromagnetic (EM) waves into the subsurface [22,23]. Conditions in the field can be very heterogeneous and many factors such as water content, grain size, mineralogical composition, organic-matter content and others may influence the propagation of the GPR signal in sediments [24].…”

Section: Introductionmentioning

confidence: 99%

Application of Ground Penetrating Radar Supported by Mineralogical-Geochemical Methods for Mapping Unroofed Cave Sediments

2018

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Ground penetrating radar (GPR) using a special unshielded 50 MHz Rough Terrain Antenna (RTA) in combination with a shielded 250 MHz antenna was used to study the capability of this geophysical method for detecting cave sediments. Allochthonous cave sediments found in the study area of Lanski vrh (W Slovenia) are now exposed on the karst surface in the so-called "unroofed caves" due to a general lowering of the surface (denudation of carbonate rocks) and can provide valuable evidence of the karst development. In the first phase, GPR profiles were measured at three test locations, where cave sediments are clearly evident on the surface and appear with flowstone. It turned out that cave sediments are clearly visible on GPR radargrams as areas of strong signal attenuation. Based on this finding, GPR profiling was used in several other places where direct indicators of unroofed caves or other indicators for speleogenesis are not present due to strong surface reshaping. The influence of various field conditions, especially water content, on GPR measurements was also analysed by comparing radargrams measured in various field conditions. Further mineralogical-geochemical analyses were conducted to better understand the factors that influence the attenuation in the area of cave sediments. Samples of cave sediments and soils on carbonate rocks (rendzina) were taken for X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses to compare the mineral and geochemical compositions of both sediments. Results show that cave sediments contain higher amounts of clay minerals and iron/aluminium oxides/hydroxides which, in addition to the thickness of cave sediments, can play an important role in the depth of penetration. Differences in the mineral composition also lead to water retention in cave sediments even through dry periods which additionally contribute to increased attenuation with respect to surrounding soils. The GPR method has proven to be reliable for locating areas of cave sediments at the surface and to determine their spatial extent, which is very important in delineating the geometry of unroofed cave systems. GPR thus proved to be a very valuable method in supporting geological and geomorphological mapping for a more comprehensive recognition of unroofed cave systems. These are important for understanding karstification and speleogenetic processes that influenced the formation of former underground caves and can help us reconstruct the direction of former underground water flows.

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Effects of magnetite on high-frequency ground-penetrating radar

Cited by 16 publications

References 42 publications

Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

Applications of the GPR Technique to indoor, bridge deck and pier structures: case studies in Turkey

Application of Ground Penetrating Radar Supported by Mineralogical-Geochemical Methods for Mapping Unroofed Cave Sediments

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