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Vulci (Viterbo Province, Italy) was one of the most important Etruscan city-states in the 1st millennium b.c. and became a Roman city in 280 b.c. The habitation site had over 1500 years of continuous life and a very large funerary area around the volcanic plateau. An international research cooperation investigated the site in 2014–2019 using remote sensing technologies and conducting archaeological excavations in the urban area. This paper presents the integrated application of remote sensing methods, which include multispectral unmanned aerial vehicles, aerial photography, and high-resolution georadar measurements. The multimodal application of active and passive sensors permitted a multilayered identification of archaeological features and led to substantial new interpretations of the rich archaeological landscape, which calls for a reconsideration of traditional scholarly narratives of Vulci's history. [ABSTRACT FROM AUTHOR]

Near-surface geophysical techniques, (i.e. ground-penetrating radar (GPR) and electric resistivity tomography (ERT)), continue to enable great possibilities for 3-D visualization of fractures and cavities. An integrated survey, including GPR and ERT, was used for mapping and evaluating a complex subsurface fracture network in Eocene limestone at Al-Mokattam site, Egypt. While only GPR was available to investigate an engineering site of about 200 × 300 m, located in Riyadh city, Saudi Arabia, for cavity detection. At the Egyptian site, GPR data were acquired with a GSSI SIR2000 system using a 400 MHz shielded antenna with 0.2 m in-line spacing. GPR data visualized using an isosurface rendering combined with inverted ERT allowed us to identify and follow the fracture system, which was mainly filled with low-resistivity sediment; such fractured limestone may cause landslides. GPR data at the Riyadh site were acquired using the RAMAC system with a 100 MHz shielded antenna attached to a GPS with real-time kinematic total station equipment; GPR data confirmed the possible presence of cavities at different depths, which may cause severe damage during building construction. In this paper, we demonstrated the efficiency of each geophysical technique available for solving subsurface engineering problems, leading to future improvements in site safety. Additionally, we indicated the efficiency of an advanced 3-D GPR visualization technique (isosurface rendering) for improving fracture and cavity detection, characterization and interpretation. [ABSTRACT FROM AUTHOR]

This study aims to the practical detection of sub-meter scale voids located inside reinforced concrete structures with different diameters and depths using different frequency antennas of 800, 1000, 1200, and 1600 MHz. The experiment was performed on two concrete blocks with medium-sized voids between 70 and 100 mm diameter, and small-sized voids between 10 and 25 mm diameter. A GPR survey was conducted by dividing each block into two grids of profiles with 50- and 100-mm profile spacing. Then, GPR data was collected along both the horizontal and vertical directions of each block with multi-frequency antennas. The gathered data was processed in 2D and 3D to detect the exact location, dimension, and brightness of these voids. The results showed that GPR has the potential to be quite effective in automating the identification and location of embedded voids within concrete blocks. The accuracy with which the system was able to identify void locations depended mainly on the frequency of the antenna used and the diameter of the void, while the depth of penetration was inversely proportional to the frequency of the used antenna, with estimated depths ranging from 25 cm (using a 1600 MHz antenna) to 1.5 m (using 800 MHz antenna). Moreover, a GPR survey was conducted to evaluate two sites inside residential buildings before and after the rehabilitation process. The radar scan exhibited a notable proficiency in identifying the positions of rebar sites, whether they were situated at a single level or two levels, inside certain areas of construction. The study revealed the ability of GPR to identify the depth of the reinforcing steel within the cement material, particularly in areas where the soil has experienced subsidence. [ABSTRACT FROM AUTHOR]

This study focuses on exploring the relationships between different categories of crypto assets and measures of uncertainty in BRIC countries, specifically examining geopolitical risk (GPR) and economic policy uncertainty (EPU). Our findings indicate that the co-movement of the EPU and GPR indexes with different categories of crypto assets is influenced by factors such as the time period, investment horizons, and the type of event, and that it differs across crypto assets. An overall pattern is observed, suggesting that the crypto market does not act as a hedge against economic policy uncertainties (EPU) but demonstrates a hedging effect against geopolitical risk (GPR). This distinction in hedging effectiveness is influenced by the nature of events (COVID-19 and the Russian invasion of Ukraine), since investors' expectations and perception of risk differ during these events. Furthermore, our analysis shows that stablecoins and memecoins do not exhibit consistent results in relation to GPR and EPU, suggesting that they may not serve as reliable hedging instruments against geopolitical risks or economic policy uncertainties in the BRIC countries. Our findings carry important implications for investors, portfolio managers, policy makers, and researchers, offering insights into portfolio risk management, regulatory frameworks, and the behavior of the cryptocurrency market in the face of uncertainties. [Display omitted] • Assessment of Cryptocurrency's relationships with BRIC's uncertainty. • Analysis focused on different uncertainty measures such as the GPR and EPU. • Crypto market does not act as a hedge against economic policy uncertainties. • Crypto market can act as a hedge against geopolitical risk. • Type of event influences the co-movement between uncertainties and crypto assets. [ABSTRACT FROM AUTHOR]

Remote sensing techniques, both on the ground (geophysical prospection) and remote (aerial and satellite imagery), have repeatedly shown their usefulness in the detection and mapping of unknown archaeological features and sites, but their results remain relatively sterile and not fully unwrapped if no archaeological verification is implemented to evaluate the reliability of the signals encountered. Employing a more coupled approach of geophysical and archaeological investigations at the Bronze Age site of Sissi on Crete, we illustrate how optimal use can be made of the results, allowing the implementation of a proper research strategy and the concentration of costly archaeological resources in the most profitable and productive ways. [ABSTRACT FROM AUTHOR]

The successive application of the georadar method to a surface study of media pushes for the creation of a logging georadar. The tool operation conditions in a deep-seated medium with high absorption of electromagnetic waves (in a borehole) require optimization of the georadar technology for logging. Two possible approaches to GPR logging are discussed by the example of various georadars. We analyze the experimental data obtained with differently constructed MALA (Sweden) and GROT 12 (Russia) georadars under the same conditions during an international expedition. Conclusions are drawn that video pulses can be used for GPR logging. [ABSTRACT FROM AUTHOR]

Gökpınar spring is one of the most important drinking water resources of Denizli city (Turkey), covering more than one third of the water need of the municipality. In this paper, we present a combination of geophysical methods in order to define the groundwater flow paths in Gökpınar spring region. The spring of Gökpınar is a result of the Fault-fracture network formed during the tectonic events which took place in the study area. This fault and fracture system present in the Gökpınar spring zone are characterized by the Cankurtaran fault in the east and Babadağ fault in the south. To highlight the main directions of the groundwater flows feeding Gökpınar spring, an electrical resistivity tomography (ERT) survey was carried out in the study area. The results obtained from this survey have been confirmed by a frequency domain electromagnetic (FEM) survey carried out along four profiles in addition to four ground penetrating radar profiles (GPR) profiles. The comparison of the two auxiliary methods with the ERT profiles allowed a better understanding of the groundwater movements. The ERT data was collected along six profiles corresponding to Wenner–Schlumberger array and located predominantly in the southern and eastern parts of the spring surrounding area. In order to confirm the hypothesis from the interpretation of the ERT profiles, two simplified different scenarios were numerically and experimentally considered. The results of the combined methods have ultimately led to define the main direction of groundwater flows feeding the Gökpınar spring, which is related to four factors: The Fault-Fracture network, karstic features, the topography, and deep groundwater. Article Highlights: Efficiency of the combined geophysical methods in groundwater flow determination. Groundwater flow direction was found to be related to the Fault-fracture network in the study area. Numerical and analog models were representative of the field results. [ABSTRACT FROM AUTHOR]

Ground Penetrating Radar (GPR) surveys in the area between Sherashevo and Inkino villages provide insights into the structure of the Delta Fault and allow estimating the amount of vertical slip caused by the M = 7.5 Tsagan earthquake of 12 January 1862. The surveys with shielded AB-90 and AB 250-M antennas of an OKO-2 georadar along five profiles spaced at 25 m reveal normal slip from 2.6 to 4.5 m in different segments of the main seismogenic fault. The surface rupture caused by the 1862 event is traceable in interpreted radar images together with subsidiary faults; some possibly resulted from the 1959 Middle Baikal earthquake (M = 6.8). The GPR data are used to construct a 3D model of the area, which illustrates the evolution of the Delta Fault scarp since the Tsagan earthquake. Much of surface rupture during the Tsagan event is due to gravity sliding, judging by the amount of displacement estimated from GPR, structural, and field data of different years. Comprehensive understanding of the displacement pattern along the seismogenic fault requires further study extended to other segments of the fault zone. [ABSTRACT FROM AUTHOR]

Ground-penetrating radar (GPR) profiling is applicable to study peatlands and swampy areas in permafrost but have some limitations in summer time. Theoretical calculations and field experiments show that estimating attenuation of electromagnetic waves is required for planning GPR survey. GPR data acquired with a 300 MHz antenna fail to resolve reflections from below the permafrost if the thaw/permafrost boundary is deeper than 1.5 m and the attenuation coefficient is 0.7, as in water-saturated peat. GPR data allow high-resolution lithological division of permafrost and provide reliable constraints on the depths to interfaces and physical properties of the ground. Thus, GPR can fully or partly substitute for the time- and labor-consuming direct measurements. The inferences have been confirmed by field results. [ABSTRACT FROM AUTHOR]

Ground Penetrating Radar (GPR) is an electromagnetic sensing technology employed for localization of underground utilities, pipes, and other types of objects. The radargrams typically obtained have a high dimensionality, containing a number of signatures with hyperbolic pattern shapes, and can be processed to retrieve information about the target's locations, depths and material type of underground soil. The classical Hough Transform approach used to reconstruct these hyperbola shapes is computationally expensive, given the large dimensionality of the radargrams. In literature, several approaches propose to first approximate the location of hyperbolas to small segments through a classification stage, before applying the Hough transform over these segments. However, the published classifiers designed for this task present a relatively complex architecture. Aiming at an improved target localization, we propose an alternative classification methodology. The goal is to classify windows of GPR radargrams into two classes (with or without target) using a neural network radial basis function (RBF), designed via a multi-objective genetic algorithm (MOGA). To capture samples' fine details, high order statistic cumulant features (HOS) were used. Feature selection was performed by MOGA, with an optional prior reduction using a mutual information (MIFS) approach. The obtained results demonstrate improvement of the classification performance when compared with other models designed with the same data and are among the best results available in the literature, albeit the large reduction in classifier complexity. [ABSTRACT FROM AUTHOR]

Abstract Three geophysical techniques such as resistivity, seismic refraction, and GPR have been applied to delineate the depth to the groundwater surface, subsurface stratigraphy and subsurface structures which control the configuration and distribution of the groundwater aquifer. Five vertical electrical sounding (VES) were measured by using Syscal-R2 instrument of electrode separation ranging from AB/2 = 1–500 m to reach depth of investigation about 150 m. The results of quantitative interpretation of the VES data indicate that the subsurface sequence composed of six geoelectric units; the first unit is characterized by resistivity values up to 2007 Ohm.m corresponding to sand & gravel and thickness up to 1.2 m. The second geoelectric unit is corresponding to sandy clay which exhibits resistivity up to 235 Ohm.m and depth up to 1.2 m. The third geoelectric unit is characterized by resistivity values up to 1483 Ohm.m corresponding to dry sand which of depth up to 2.6 m. The fourth geoelectrical unit consists of sand saturated with ground water and exhibits resistivity values ranging from 20.2 to 52.9 Ohm.m and depth ranging from 7 to 16.8 m. The fifth geoelectrical unit reveals resistivity values ranging from 7 to 32.6 Ohm.m and consists of sandy clay saturated with groundwater of depth up to 111 m overlaying the sixth unit which reached to depth up to 165 m and characterized by resistivity values ranging from 54 to 91 Ohm.m corresponding to sandstone saturated with ground water. Five shallow seismic refraction spreads of geophone spacing 4 m were measured to investigate the subsurface sequence, where the results of interpretation indicate that the subsurface section consists of three seismic layers; the first layer is unsaturated overburden with seismic velocity range from 280 to 770 m/s and thickness reach about 6 m. The second layer is sand saturated with ground water with velocity range from 760 to 1300 m/s and maximum thickness of about 7 m overlaying the third layer reached to depth up to 24 m and corresponding sandy clay saturated with groundwater with seismic velocity range from 1130 to 2260 m/s. Five GPR profiles are measured using MALA RAMAC GPR System with a Rough Terrain Antenna (RTA) system of central frequency of 100 MHz. The interpretation of GPR data indicate that the expected water table ranging from 8 m to 11 m in the study area. Interpretation of the obtained results and correlation with the available geological and different geophysical data revealed that, the depth to the groundwater table of the investigated area ranges between 7 and 16.8 m. [ABSTRACT FROM AUTHOR]

Abstract Optically-stimulated luminesecne (OSL) dating, in concert with two-dimensional ground-penetrating radar (GPR) profiling, has contributed to significant advances in our understanding of beach-ridge systems and other sedimentary landforms in various settings. For recent beach-ridges, the good OSL properties of coastal quartz permit a high sample throughput thanks to shorter measurement times and simpler sample preparation prompting the collection of more samples at higher sampling resolution. However, sampling at high resolution increases the chance of age inversions because random errors between samples may be larger than the difference in sample ages. Age inversions can be avoided, however, if the stratigraphic constraints are included in the age estimation process. Here, we create a custom Bayesian chronological model for a recent (<500 yr) beach-ridge sequence in Moruya, southeast Australia, for direct comparison with a GPR profile. The model includes a full 'burial-dose model' for each sample and a dose rate term with the modelled ages constrained by the vertical and shore-normal sample order. The modelled ages are visualized by plotting isochrones on the beach-ridge cross section, and validated against a beach monitoring dataset. The modelling approach allows a more detailed interpretation of the Moruya beach-ridge system; when combined with higher-resolution sampling, the approach will increase the precision of beach-ridge chronologies and provide further insights into their formative processes. [ABSTRACT FROM AUTHOR]

Abstract The row vector and column vector of a ground penetrating radar (GPR) B-scan image have different physical meanings, and the features of heterogeneous medium properties based on these vectors can provide new possibilities for hyperbola classification. This study uses the features of both row and column vectors (i.e., twin vectors), gray statistics, and united coding to produce a twin gray statistics sequence (TGSS), a representation of the GPR image, based on information entropy. An actual dataset and multiple classification methods are used to compare and evaluate the robustness and dimension reduction performance of TGSS. The results show that the proposed method has relatively favorable robustness and steady dimension reduction performance in the test environment with a small number of samples and class imbalance. [ABSTRACT FROM AUTHOR]

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The present study focuses on preparing the wetland map using earth observation data and applying a novel ensemble model. Eight advanced machine learning algorithms were applied to determine the probability of the occurrence of wetlands. The random forest (RF), support vector machine (SVM), and multivariate adaptive regression spline (MARS) models outperformed others. So, these models were further used to create a stacking ensemble for improving precision. The RF-SVM-MARS ensemble model was run with seven various parameters. The results show that the integrated parameter has the highest area under the curve (0.960) followed by optical-hydrogeomorphic (0.953), SAR-hydrogeomorphic (0.940), hydrogeomorphic (0.896), SAR-optical (0.892), optical (0.881), and SAR (0.702). The hydrogeomorphic variables exhibited greater influence than the optical and SAR variables. However, the integration of all selected key variables proved to be the most effective approach for probabilistic wetland mapping. The RF-SVM-MARS ensemble model can improve classification accuracy as compared to a single model. An accuracy of 96% was obtained when the ensemble model output was cross-validated with field data. The ground-penetrating radar (GPR) tool was also successfully employed to study the sub-surface strata and water level conditions in wetland and non-wetland areas. The successful application of a new ensemble approach along with the GPR technique for coastal wetland mapping in this study could encourage researchers to choose it as an appropriate methodology. Moreover, the outcomes of the work will help land-use planners and government agencies for better planning, monitoring, and promoting sustainable development of the coastal area. • Multiple datasets (Optical, microwave, and hydro-geomorphic) were applied. • The efficiency of eight advanced machine learning models was evaluated and compared. • New ensemble model was applied for probabilistic coastal wetland mapping. • The GPR technique was employed to understand sub-surface architecture of wetland. [ABSTRACT FROM AUTHOR]

Ground penetrating radar (GPR), which can reveal the sedimentary structure and development process of dunes, is widely used to evaluate aeolian landforms. The interpretations for GPR profiles are mostly based on qualitative descriptions of geometric features of the radar reflections. This research quantitatively analyzed the waveform parameter characteristics of different radar units by extracting the amplitude and time interval parameters of GPR data in the Mu Us Sandland in China, and then identified and interpreted different sedimentary structures. The results showed that different types of radar units had specific waveform parameter characteristics. The main waveform parameter characteristics of sand dune radar facies and sandstone radar facies included low amplitudes and wide ranges of time intervals, ranging from 0 to 0.25 and 4 to 33 ns respectively, and the mean amplitudes changed gradually with time intervals. The amplitude distribution curves of various sand dune radar facies were similar as unimodal distributions. The radar surfaces showed high amplitudes with time intervals concentrated in high-value areas, ranging from 0.08 to 0.61 and 9 to 34 ns respectively, and the mean amplitudes changed drastically with time intervals. The amplitude and time interval values of lacustrine radar facies were between that of sand dune radar facies and radar surfaces, ranging from 0.08 to 0.29 and 11 to 30 ns respectively, and the mean amplitude and time interval curve was approximately trapezoidal. The quantitative extraction and analysis of GPR reflections could help distinguish various radar units and provide evidence for identifying sedimentary structure in aeolian landforms. [ABSTRACT FROM AUTHOR]

There are many approaches available to separate the background and foreground in image processing applications. Currently, researchers are focusing on wavelet De-noising, curvelet threshold, Edge Histogram Descriptor threshold, Otsu thresholding, recursive thresholding and adaptive progressive thresholding. In fixed and predictable background conditions, above techniques separate background and foreground efficiently. In a common scenario, background reference is blind due to soil surface moisture content and its non-linearity. There are many methodologies proposed from time to time by researchers to solve this blind reference background separation. But challenges still now remain, because there are two major problems in ground penetrating radar imaging such as targets like ground enhances the false alarm and non-metallic target detection, where the threshold decision is a critical task. In this paper, a novel real time blind adaptive threshold algorithm is proposed for ground penetrating radar image processing. The blind threshold was decided to use normal random variable variance and image data variance. Further, the image was smoothened by random variance ratio to image data variance. Experimental results showed satisfactory results for the background separation and smoothening the targeted image data with the proposed algorithm. [ABSTRACT FROM AUTHOR]

The extraction of quantitative information from Ground Penetrating Radar (GPR) data sets (radargrams) to detect and map underground utility pipelines is a challenging task. This study proposes several algorithms included in the main stages of a data processing chain associated with radar- grams. It comprises pre-rocessing, hyperbola enhancing, hyperbola detection and localization, and parameter extraction. Additional parameters related to the GPR system such as the frequency band and the polarization bring data sets additional information that need to be exploited. Presently, the algorithms have been applied step by step on synthetic and experimental data. The results help to guide future developments in signal processing for quantitative parameter estimation. [ABSTRACT FROM AUTHOR]

The paper examines methods of assessing the critical fractures and quality of an ornamental stone deposit. Fracture status was evaluated by an in-situ Ground Penetrating Radar (GPR) test. The resulting 3D GPR model allowed exploration of the extension, shape, and orientation of the detected fractures surfaces. It also identified a rock stratum with a noticeably lower load of critical fractures compared to the other strata. Physico-mechanical properties were investigated by laboratory tests allowing classification of the deposit into quality categories, which provided a promising correlation with the GPR survey results. [ABSTRACT FROM AUTHOR]

Ul is an archaeological site located on a hilltop near modern Oliveira de Azeméis (NW Portugal). It had several occupations over time, at least sporadically since the Bronze Age, and is nowadays a small parish with a number of scattered houses and a church, built against and around the Northern slope. Occasional fieldwork, some of it lacking publication, was carried out during the 20th century, followed by a new set of test trenches, as well as two series of geophysical surveys using GPR and electomagnetic induction methods. Some of the results from both the non-invasive and invasive approaches are presented in this paper, and integrate an ongoing discussion about Iron Age and Roman settlement in the NW of the Iberian Peninsula. [ABSTRACT FROM AUTHOR]

Flexible soil-steel structures are commonly used due to its advantages including quicker construction process, lower cost of erection and maintenance, architectural values and others. However its behavior differs from classic rigid structures. It may be the reason why principles of soil-steel structures’ work are not always completely understood and lack of grasp may cause construction and design faults. To enable its detection and elimination non-destructive testing methods should be used. These methods are widely applied due to possibility of insight into inside of the completed structure. Nowadays, one of the most popular NDT methods is Ground Penetrating Radar method. It is commonly used in communication engineering for technical condition assessment of road and airfield pavements, railway embankments or bridge decks. To date this method is not widely used for flexible soil-steel structures’ inspections. This paper shows application of GPR method for SuperCor structure study. As a result of the research series of processed radargrams were obtained. They allowed to detect construction incorrectness of backfill layers and drainage elements. Presence of these anomalies may affect the sustainability which is dependent on the proper execution of drainage system. Case study presented in this paper may be helpful in determining reasons of incorrect behavior of soil steel structures during its exploitation what was repeatedly reported by road administrators. [ABSTRACT FROM AUTHOR]

Precast pre-post-tensioned concrete beams are commonly used in transport engineering. Significant number of bridge structures is being built with the use of precast girders due to their advantages such as quick construction process, moderate cost and reduction of scaffolding and shuttering works. To avoid failures, precast structural members must be subjected to strict quality control that requires the use of the non-destructive testing methods. One of the most suitable NDT methods for precast girders inspection is the Ground Penetrating Radar method. The aim of the research described in this paper was to evaluate the parameters of prefabricated ‘T’ bridge girders with the use of the Ground Penetrating Radar method. The beams were investigated upon the producer's request in order to assess the correctness of the production process. The georadar measurement was conducted and the raw data were processed with dedicated software. As a result of the study, a series of radargrams were attained. Based on these data, the rebar location and cover depth as well as pre-tensioning and post-tensioning cable trajectories were determined. The results allowed defining capabilities and limitations of the Ground Penetrating Radar method with regard to quality control of prefabricated concrete elements. [ABSTRACT FROM AUTHOR]

The Mondy strike-slip fault connects the W-E Tunka and N-S Hovsgol basins on the southern flank of the Baikal rift system. Ground penetrating radar (GPR) surveys in its damage zone provide constraints on thicknesses, dips, and plunges of fault planes, as well as on the amount and sense of vertical slip. Strike-slip faulting in the southern segment of the Mondy fault within the territory of Russia bears a normal slip component of motion along the W-E and NW planes. These motions have produced negative flower structures in shallow crust appearing as grabens upon Pleistocene fluvioglacial terraces. The amount of normal slip estimated from the displacement of reflection events varies over the area and reaches its maximum of 3.4 m near Mondy Village. In the Kharadaban basin link, left-lateral strike slip displaces valleys of ephemeral streams to 22 m, while normal slip detected by GPR reaches 2.2 m; this normal-to-strike slip ratio corresponds to a direction of ~ 6° to the horizon. The angles of dips of faults are in the range 75°-79°; the thicknesses of fault planes marked by low- or high-frequency anomalies in GPR records vary from 2.5 to 17.0 m along strike and decrease with depth within a few meters below the surface, which is common to near-surface coseismic motions. Many ruptures fail to reach the surface but appear rather as sinkholes localized mainly in fault hanging walls. The deformation style in the damage zone of the Mondy fault bears impact of the NW Yaminshin fault lying between its two segments. According to photoelasticity, the stress field changes locally at the intersection of the two faults, under NE compression at 38°, till the inverse orientations of principal compression and extension stresses. This stress pattern leads to a combination of normal and left-lateral strike slip components. [ABSTRACT FROM AUTHOR]

Government business process reengineering is the basis and prerequisite for the implementation of e-government, business process reengineering will largely influence the potential of e-government information technology, and the effect of E-government in the reform of government management mode. This paper from the relationship between e-government and government business process reengineering based on the effective use of information technology and information resources as the goal, to clarify the e-government and government business process reengineering are interactive, complementary and mutually reinforcing. And then from the point of view of e-government information system implementation, the e-government information system model based on government business process reengineering is put forward, and the current government information model and e-government information model are compared. [ABSTRACT FROM AUTHOR]

In 1997, Quercus bicolor and Quercus phellos in a New York City streetscape were planted in CU-Structural Soil under a concrete sidewalk and in a tree lawn with the intention of observing long term plant response as a comparative study of an early installation of the new designed soil method. The trees have been measured nine times since the second year post-installation. We present the growth of trunk diameter, height and slenderness ratios. To verify root colonization in the structural soil under the sidewalk, tree root presence was measured using ground-penetrating radar in 2009, year 12. In the 17th year, trees in the sidewalk were similar in size with a higher level of survivorship as compared to the trees in the tree lawn. Adjusting for year of replacement in the tree lawn, model predictions for diameter of trees 15 years post-installation were no different for Q. bicolor in either the sidewalk (21.38 cm) or the tree lawn (22.05 cm). Q. phellos in the tree lawn were predicted to be slightly larger, 34.29 cm versus 31.34 cm in the sidewalk. Roots had colonized the structural soil under the sidewalk to 60 cm, its full depth. This provided evidence that the structural soil medium served as an acceptable rooting environment. [ABSTRACT FROM AUTHOR]

When measurements by a Ground Penetrating Radar are evaluated, a dielectric constant is very important electrical property of pavement materials. The numerical value of the dielectric constant is different for various materials used in road construction and it affects the signal velocity in pavement layers. The main subject of research outputs introduced in the article is comparison of dielectric constants of the various asphalts calculated from time intervals and amplitudes. The series of laboratory and in situ measurements were made on three different asphalts (Asphalt Concrete (AC), Porous Asphalt (PA) and Stone Mastic Asphalt SMA)). The Ground Penetrating Radar (GPR) with 2 GHz air-coupled antenna was used. The antenna was moved over three sections: floor, a steel plate and an asphalt slab. The dielectric constant of asphalt was determined using time interval between positive amplitudes peaks representing the asphalt slab thickness and also using the amplitudes values. It was found the dielectric constants of the AC, PA and SMA differed regardless the calculation method. Differences in dielectric constant values were also found between two calculation methods. [ABSTRACT FROM AUTHOR]

Recently, a considerable large emphasis is put on diagnostic methods, which are non-invasive, simple, safe, time efficient and non-intrusive from the viewpoint of interference with traffic flow of particular road. From this point of view, very convenient is use of the GPR method in terms of the pavement and road investigation. We used two Horn antennas (1 GHz and 2 GHz) on the test field to verify its construction. [ABSTRACT FROM AUTHOR]

In the framework of WAter Re-BOrn Project a large pond in Mereto (upper Friuli plain) was chosen as artificial recharge test site. Several geophysical investigations (GPR, Electrical Resistivity Tomography and High Resolution Seismic) were carried out to study and to characterize the vadose zone of this large infiltration basin. These geophysical integrated methods supplied us many information to characterize the vadose zone and the unconfined aquifer in the study area. The geophysical information greatly reduces the hydrogeological knowledge gaps and was used to improve the three-dimensional Finite Element numerical model to predict the effect of the artificial recharge. [ABSTRACT FROM AUTHOR]

• Ground Penetrating Radar images obtained of a large Namib Sand Sea linear dune. • Strata up to ∼ 10 m depth show scouring and abrupt changes. • Alternating strata reveal changes in dominant wind direction. • Subsurface patterns reveal down-axis transport of sand. • Implications for wind direction and sand transport on Saturn's moon Titan. We imaged the near-surface sedimentary structures of a large linear dune, flanking dune forms and an associated crossing linear dune never before studied in the northern Namib Sand Sea using 200-MHz Ground-Penetrating Radar (GPR). The dry, uniform sandy conditions and wavelength used allowed for highly detailed observations of sedimentary structures to depths of ∼ 12 m across a >1km lateral scan. Sedimentary features observed in the main linear dune include scouring and abrupt changes in strata such as trough cross stratification (TCS), onlap, downlap, truncation and avalanche-related bedding, all a result of complex sand transport conditions. Different phases of deposition have produced an opposed succession of strata on each side of the dune. These successions alternate 2-dimensional (2D), or bedform instability mode features with 3-dimensional (3D), or fingering mode features, separated by a clear process boundary. These alternating successions reflect a change in the dominant wind environment in the recent past. The changing winds may feed into the building and overall stability of this dune field and may be a model for conditions in other large linear/longitudinal dune fields. The subsurface structure of an oblique crossing linear dune demonstrates sand transport generally down the dune long axis in the direction predicted from modern, ERA-Interim model as well as paleoclimate model winds. This suggests relatively long-term stability of this intermediate-sized landform and the potential long-term coexistence of large dunes and secondary forms. These studies have implications for the extensive sand seas of Titan, where lack of large secondary forms may indicate a simple wind regime over long time periods. [ABSTRACT FROM AUTHOR]

Knowledge of the existing roadway condition is vital to transportation government agencies for management and safety purposes. Verifying the presence and extent of subsurface defects/voids is vital to prevent failures and accidents from occurring. A nondestructive and noninvasive geophysical method, ground penetrating radar (GPR), which utilizes electromagnetic waves, was employed in this study. Four field projects are presented in this study to demonstrate the application of electromagnetic waves for detection of voids and anomalies. Auguring and excavation were used to verify the suspicious areas that were located by the electromagnetic waves. Voids and different subsurface features, like rebar, geo-grid, and geo-textile, were successfully detected. A large negative peak that appears in the wave form is an indication of a dry void. Void sizes, ranging from a few centimeters to several meters, were successfully detected. Early identification of concealed subsurface voids under the roadway structure can prevent major failures from occurring. The methodologies presented in this study are applicable to many other projects. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents the Ground Penetrating Radar (GPR) testing to determine the parameters of reinforced concrete (RC) viaduct beams. The non-destructive assessment of the condition of engineering structures using GPR has lately become quite an attractive and effective method of testing. The subject of this study is a three-span RC road viaduct. In relation to the adopted reinforcement method and the lack of design documentation for the existing viaduct, it was necessary to obtain basic information on the beams occurring in the object. The main purpose of the experimental tests using the GPR technique was to determine the geometric parameters of beams and reinforcing bars within them. The distances between particular reinforcing bars and the depth of their position were also to be determined. Conclusions drawn from the tests can be helpful in measurements using the GPR technique, especially for tests of RC bridges. [Copyright &y& Elsevier]

The article presents the analysis of both, synthetic and experimental Ground Penetrating Radar (GPR) data by the use of curvelet transform. The images, received from GPR technique, called B-scans are 2D images, where the first dimension represents time and the other one represents depth. These images are often low resolution and noisy. Besides, B- scans are often very difficult to interpret even for experts. That is why the curvelet transform has been applied to clarify the meaning of images. We have shown that the image analysis process of B-scans can be automated by the use of curvelet transform, which lets us detect the edges in any angle in the image under consideration. It was proven that the proper analysis and the choice of curvelet transform coefficients allows to clearly specify the location of the target. The main advantage of the curvelet analysis is the efficient detection even when we deal with low resolution and noisy images. [ABSTRACT FROM AUTHOR]

Abstract: Successful implementation of site-specific irrigation requires an understanding of within-field-variability of soil parameters. These parameters can be estimated by direct sampling or by indirect surveying using geophysical data. The geophysical outputs are quite sensitive to soil water content; therefore, they can be used as covariates in soil water content (SWC) estimation. The objectives of this study were to use geophysical and soil data as auxiliary variables in the estimation of soil water content through geostatistical techniques. The surveys were carried out in a test site at the agricultural experimental farm located in south-eastern Italy in dry and wet soil conditions. The plot was surveyed with an EMI sensor and two different mono-static GPR systems, one with central frequencies of 600/1600MHz and the other with a central frequency of 250MHz. Forty-eight soil cores were collected for laboratory analysis of textural properties. One hundred and sixteen soil samples up to 0.30m-depth were collected to measure the SWC with gravimetric method. Kriging with external drift (KED), a non-stationary geostatistical technique, was used to estimate SWC with EMI, GPR and soil data as covariates. Cross-validation test was used to assess the goodness of the estimates and compare KED with ordinary kriging. The results showed that the approach using the auxiliary variables can be preferred to univariate kriging in terms of correlation between true and estimated values and capability of interpretation of spatial variability. Kriging with external drift proved to be a valid tool in sensor data fusion and could be effectively applied in Precision Irrigation. [Copyright &y& Elsevier]

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This study involved field investigations of spalling in several partial-depth precast, prestressed concrete bridge decks through nondestructive testing. Ground penetrating radar (GPR) was used to assess the condition of concrete throughout the deck to identify areas of cracking and corrosion, as well as the condition of prestressing tendons in the precast, prestressed concrete panels. Particular techniques were used to identify areas of delamination at the interface between the panels and cast-in-place concrete topping. Core sampling and visual inspection were used to interpret and validate GPR data. Findings indicate that transverse reflective cracks at the panel joint locations played a key role in spalling. Combined data analyses showed that the spalling observed results from penetration of water and chlorides through reflective cracking in the cast-in-place concrete topping at the panel joints to the cast-in-place concrete topping and precast, prestressed concrete panel interface, then through the panels to the prestressing tendons. Concrete integrity increased with increased cast-in-place concrete topping reinforcement in the bridge longitudinal direction because such reinforcement serves as transverse crack control and thus delays the onset of spalling. [ABSTRACT FROM AUTHOR]

Thickness of the pavement structure layers represents an important data for the implementation into the database of roads already constructed, during the pavement strengthening design, particularly if the appraisal of the bearing capacity of the pavement structure is done by means of the Falling Weight Deflectometer, during reconstruction of pavements or during control of the newly constructed roads. If reconstruction is carried out by procedures of recycling of the existing pavement the details about the thickness of asphalt layers are important not only when determining the depth of the intervention but also when designing asphalt mixture. During quality control of the newly constructed road sections the Ground Penetrating Radar (GPR, georadar) can be used as the instrument for fast and efficient determination of the thickness of layers. Measuring is done at speeds that approx correspond to the speeds of traffic flow, so that disturbance of traffic is minimum, whereby the safety of participants in traffic and measuring personnel is increased. The paper presents several examples of determining the thickness of layers of road pavement structures by the non-destructive GPR method. The obtained results were compared to conventional methods of determining thicknesses that are used in Croatia, i.e. coring or data obtained by surveying methods during construction of the pavement structural layers. Measurements were done on completely new and existing roads of different age having the asphalt pavement. [ABSTRACT FROM AUTHOR]

Abstract: GPR (Ground penetrating radar) is one kind of the detection technologies with rapid, non-destruction, uninterrupted detection, and high-resolution. GPR can be applied to detect underground holes and loose soil layer and the other baneful anomalies, and therefore is widely applied to hole survey of the subway project in recent years. Based on briefly describing engineering geological background between F station and L station of a subway project in Beijing, this paper gives the arrangement method of GPR survey line in the construction area of shield method, analyzes detection results, verifies an anomaly by spading, determines the distribution range and its characteristic of the hole anomalies. The results showed that three obvious anomalies were detected in the area between F station and L station, and seriously loose soil layer was the cause of No. 1 and No. 3 anomalies, and hole was the cause of No. 2 anomaly. Thereby the anomalies of loose soil layer and hole could be detected accurately by the GPR technology, and then basic data of underground holes could be obtained. On the base of analyzing these data, effective measures could be adopted to avoid the hidden danger, then the safety of subway construction and surrounding environment of the subway project could be ensured. [Copyright &y& Elsevier]

Abstract: Determination of background permittivity and removing of the direct wave is one of the main problems in data processing on Ground Penetrating Radar. The interference of direct wave will greatly affect the accuracy and the resolution of GPR imaging. We propose an f-k filtering approach for the solution, which use a difference of an apparent velocity between a direct wave and a reflection from a target. Besides, a Stolt migration algorithm combined F-K filter with minimum entropy technique is proposed to improve the focus effect of the radar image and realize the precise inversion of background relative permittivity. Synthetic data generated by FDTD have been used to test the improved migration algorithm, and the results show that the presented algorithm can achieve comparative results produced by windowed filter based Stolt migration algorithm. [Copyright &y& Elsevier]

Abstract: The Nipissing phase was the last pre-modern high-water stage of the upper Great Lakes. Represented as either a one- or two-peak highstand, the Nipissing occurred following a long-term lake-level rise. This transgression was primarily an erosional event with only the final stage of the transgression preserved as barriers, spits, and strandplains of beach ridges. South of Alpena, Michigan, mid to late Holocene coastal deposits occur as a strandplain between Devils Lake and Lake Huron. The landward part of this strandplain is a higher elevation platform that formed during the final stage of lake-level rise to the Nipissing peak. The pre-Nipissing shoreline transgressed over Devils Lake lagoonal deposits from 6.4 to 6.1ka. The first beach ridge formed ~6ka, and then the shoreline advanced toward Lake Huron, producing beach ridges about every 70years. This depositional regression produced a slightly thickening wedge of sediment during a lake-level rise that formed 20 beach ridges. The rise ended at 4.5ka at the Nipissing peak. This peak was short-lived, as lake level fell >4m during the following 500years. During this lake-level rise and subsequent fall, the shoreline underwent several forms of shoreline behavior, including erosional transgression, aggradation, depositional transgression, depositional regression, and forced regression. Other upper Great Lakes Nipissing platforms indicate that the lake-level change observed at Alpena of a rapid pre-Nipissing lake-level rise followed by a slower rise to the Nipissing peak, and a post-Nipissing rapid lake-level fall is representative of mid Holocene lake level in the upper Great Lakes. [Copyright &y& Elsevier]

Abstract: A large active parabolic dune along the coast of Pará State, northern Brazil, was analyzed using aerial photography and imaged with high-resolution ground-penetrating radar (GPR) to map the subsurface facies architecture and point-source anomalies. Most high-amplitude (8–10dB) subsurface anomalies are correlated with partially buried mangrove trees along the leading edge (slipface) of the advancing dune. Profiles along a 200-m long basal stoss side of the dune reveal 66 targets, most of which lie below the water table and are thus inaccessible by other methods. Signal amplitudes of point-source anomalies are substantially higher than those associated with the reflections from continuous subsurface features (water table, sedimentary layers). When complemented with exposures and excavations, GPR provides the best means of rapid continuous imaging of the geological record of complex interactions between vegetation and aeolian deposition. [Copyright &y& Elsevier]

The oral health of children became a more prominent concern with the U.S. surgeon general's report on oral health in America in 2000. The purpose of our study was 1) to assess General Practice Residency (GPR) and Advanced Education in General Dentistry (AEGD) (here jointly referred to as advanced general dentistry [AGD] programs) directors' current behaviors with regard to pediatric training of residents and 2) to assess their attitudes about which components of pediatric oral health training should be included in AGD programs. A twenty-one item survey was mailed to all GPR and AEGD programs accessed through the American Dental Association website. Seventy percent of directors (N=187) completed and returned the survey. Responses indicated that AGD residents receive adequate clinical exposure to pediatric patients and provide much-needed services to uninsured, underinsured, and underserved people. Although clinical training in pediatric treatment was high, didactic hours focused on pediatric treatment did not seem commensurate with clinical activity. Program directors indicated strong attitudinal support for teaching residents many components of pediatric oral health care, although most directors have concerns over increasing didactic hours spent on pediatric oral health due to already crowded curricula. Approximately 88 percent of directors said that they would implement a pediatric oral health module in their curricula if they had access to one. [ABSTRACT FROM AUTHOR]

Super-resolution is very important for the signal processing of GPR (ground penetration radar) to resolve closely buried targets. However, it is not easy to get high resolution as GPR signals are very weak and enveloped by the noise. The MUSIC (multiple signal classification) algorithm, which is well known for its super-resolution capacity, has been implemented for signal and image processing of GPR. In addition, conventional spectral estimation technique, FFT (fast Fourier transform), has also been implemented for high-precision receiving signal level. In this paper, we propose CPM (combined processing method), which combines time domain response of MUSIC algorithm and conventional IFFT (inverse fast Fourier transform) to obtain a super-resolution and high-precision signal level. In order to support the proposal, detailed simulation was performed analyzing SNR (signal-to-noise ratio). Moreover, a field experiment at a research field and a laboratory experiment at the University of Electro-Communications, Tokyo, were also performed for thorough investigation and supported the proposed method. All the simulation and experimental results are presented. [ABSTRACT FROM AUTHOR]