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Aiming to address the issue of significant artefact interference in conventional reverse time migration (RTM) imaging under zero-time imaging conditions of ground-penetrating radar (GPR), this study proposes an improvement of RTM using cross-correlation superposition projection (CSP) to enhance imaging quality. The method is based on the original RTM imaging framework, where all single-trace signals are individually processed using RTM. The individual imaging results are then multiplied pairwise and added together to create a CSP. After normalizing the CSP and properly setting the adaptive threshold, the CSP can focus RTM imaging on the GPR signal reflection interface area, effectively removing artefact interference. Synthetic data test confirms that the CSP-improved RTM, when compared to conventional RTM and Laplace filtering methods, not only preserves all effective information in imaging but also eliminates artefact interference. This improvement significantly enhances the quality and resolution of the imaging results. Furthermore, the practicality and effectiveness of the CSP-improved RTM method in engineering applications have been validated using a set of measured GPR data. [ABSTRACT FROM AUTHOR]

An extensive network of pipelines is extensively employed worldwide to carry oil and gas fluids over millions of kilometers. The pipeline channel was constructed to resist environmental dynamic loading conditions to provide safe and reliable oil and gas fluids transportation from the production well sites to depot stations installed at sea coastlines. However, pipeline infrastructure damages such as fractures, cracks, leakages, etc., are significant sources of economic losses in pipeline operations. Moreover, pipeline failures can cause considerable ecological catastrophes, human deaths, and financial loss. Important research initiatives have been committed to establishing pipeline breach detection and localization using various techniques to avoid these threats and maintain a secure and dependable pipeline network. This paper reviews different state-of-the-art damage detection methods and their recent advancement with a case study explaining the application of light detection and ranging for pipeline damage detection. The pros and cons of diverse damage detection methods in pipeline networks are also discussed. Research gaps for pipeline damage detection systems are also provided for better understanding and future research. [ABSTRACT FROM AUTHOR]

Ground penetrating radar (GPR) is an effective tool in cryosphere and climate research, as it can provide detailed, non-invasive insights into ice thickness, internal structures, and subglacial conditions. This technology uncovers critical data on glacier dynamics and climate change impacts, enhancing our understanding of past, present, and future environmental shifts. In this contribution, the design and experimental verification of a lightweight, surface-based GPR platform intended for imaging glacial subsurface structures is presented. Therein, the system requirements for glaciological applications and the design implications for the developed platform and its components are described. In addition, a detailed overview of the utilized radar system, including the 3D-printed horn antennas and the localization concept, is provided. Furthermore, the imaging properties of the developed system are introduced, and the processing chain to retrieve subsurface images from the raw radar data using synthetic aperture radar concepts is presented. The platform was tested during a field campaign in March 2024 on the Jungfraufirn glacier in Switzerland. The data from this field campaign provide detailed imaging results of the glacier subsurface, including its stratification with high resolution and contrast. Moreover, a comparison of our rather broadband ultra-high frequency GPR measurements to the data acquired with a high-performance state-of-the-art low frequency GPR system is provided. Finally, this contribution concludes with current limitations and an outlook on future improvements.

Peatlands, as an important carbon sink, store a large amount of atmospheric carbon that is vulnerable to becoming a carbon emission source due to the disturbance of the peat layer by natural and anthropogenic processes. The Kuan Kreng peat swamp forest is the second largest peatland in Thailand and is in coastal wetland serving for carbon stock in the subsurface. To assess carbon stock in peatland, the thickness and distribution of the peat layer are necessary. This study determines physical and chemical characteristics of the peatlands in the coastal wetland, southern Thailand by conventional core study and geophysical surveys, including ground penetrating radar (GPR) and electrical resistivity imaging (ERI). There is a significant relationship between chemical and physical properties from the peat layer, which is useful to approximately predict the physical properties and peat layers in the geophysical profiles. The resistivity profiles exhibit high resistivity response, peat between 21.9 and 145.0 ohm-m, interpreted as the peat layers in the shallow subsurface. The high resolution GPR profiles provide an average GPR velocity in peat of 0.040 m/ns and a relative dielectric constant of 54.9 for the peat layers. The peat layer is characterized by a high amplitude of reflection in the GPR profiles. The thickness of the peat layers was estimated from the geophysical surveys and the drilling cores having an average thickness of 18 cm. Average values of bulk density (0.19 g/cm3) and TOC (31.18 wt. %) from the drilling core samples are used to calculate the carbon density in the peat layers giving a result of 59.24 Kg C/m3. Hence, the carbon stock at the Kuan Kreng peat swamp forest is estimated at least 7.53 megaton carbon, which is much higher than aboveground biomass carbon in this area. The innumerably high amount of carbon stock could raise awareness of peatland disturbances. [ABSTRACT FROM AUTHOR]

Underground three-dimensional topography measured by sounding of radio waves with the help of ground penetrating radar (GPR) has been studied. Our goal is to obtain and analyze a 3D representation of experimental data on the passage of plane polarized electromagnetic radiation through real underground objects and the intensity of its reflection received by the receiver antenna. We are developing an inductive method. The radio sounding using of the GPR SDI K-5 with frequency range of 1÷10 MHz at depths of 10, 20 and 40 m and surface area 50×20 m has been researched. Experimental data of radio sounding was written in the ASCII table by microcontroller. The use of computer processing by OriginLab program of experimental GPR data made it possible to obtain a three-dimensional image of the anomalous area, from which the reflected electromagnetic signal comes much weaker than from neighboring areas. Measuring the response of only the electrical component makes it possible to identify areas containing water, since water has a dielectric constant that is much higher than that of terrestrial rocks. Measuring the response of only the magnetic component makes it possible to detect anomalous regions containing materials with high magnetic permeability and significantly affecting the intensity of the reflected radio wave. The accuracy of determining the geometric dimensions is limited by our measurement step for surface (5 m) and sounding underground depths (10, 20 and 40 m). This is sufficient for large underground domain. The information content of 3D graphs and the accuracy of measurements of geometric parameters can be significantly increased.

Peatlands, as an important carbon sink, store a large amount of atmospheric carbon that is vulnerable to becoming a carbon emission source due to the disturbance of the peat layer by natural and anthropogenic processes. The Kuan Kreng peat swamp forest is the second largest peatland in Thailand and is in coastal wetland serving for carbon stock in the subsurface. To assess carbon stock in peatland, the thickness and distribution of the peat layer are necessary. This study determines physical and chemical characteristics of the peatlands in the coastal wetland, southern Thailand by conventional core study and geophysical surveys, including ground penetrating radar (GPR) and electrical resistivity imaging (ERI). There is a significant relationship between chemical and physical properties from the peat layer, which is useful to approximately predict the physical properties and peat layers in the geophysical profiles. The resistivity profiles exhibit high resistivity response, peat between 21.9 and 145.0 ohm-m, interpreted as the peat layers in the shallow subsurface. The high resolution GPR profiles provide an average GPR velocity in peat of 0.040 m/ns and a relative dielectric constant of 54.9 for the peat layers. The peat layer is characterized by a high amplitude of reflection in the GPR profiles. The thickness of the peat layers was estimated from the geophysical surveys and the drilling cores having an average thickness of 18 cm. Average values of bulk density (0.19 g/cm3) and TOC (31.18 wt. %) from the drilling core samples are used to calculate the carbon density in the peat layers giving a result of 59.24 Kg C/m3. Hence, the carbon stock at the Kuan Kreng peat swamp forest is estimated at least 7.53 megaton carbon, which is much higher than aboveground biomass carbon in this area. The innumerably high amount of carbon stock could raise awareness of peatland disturbances.

The purpose of this work is to analyse the cracks in a test area of the Cărpiniș travertine quarry, based on investigations by the Ground Penetration Radar method. These analyses are part of an ERA-MIN project entitled "Artificial Intelligence and combined survey techniques for the optimization of stone quarries", acronym AI-COSTSQO, ongoing with partners from Turkey, Italy, Slovenia and Romania. Data collection was carried out with AKULA 9000C equipment, on profiles with 1m equidistant, both longitudinally and transversely. The data were collected on the Cărpiniș quarry, in three sites that were chosen according to dimensions, quarry position and geotechnical rock properties. Also, data were collected according to visible natural discontinuities, including their orientation, spacing, span and length. The data were processed to calculate the orientation and position of natural discontinuities in depth. This information will be used to identify the optimal cutting directions in the marble blocks. Mathematical model development, based on cracks detected in the quarry, will take into account the minimum and maximum limits of the cuboids, the polyhedrons and commercial volumes, but also joints and cracks in the rock. [ABSTRACT FROM AUTHOR]

Aiming at solving the clutter flooding problem in the traditional cross correlation reverse time migration (RTM) of ground penetrating radar (GPR), we proposed an improved RTM method based on multitraces cross correlation window (MCW) imaging condition. The main difference between the proposed method and the traditional direct stacking is that it can effectively enhance the effective signal while weakening the clutter by performing MC calculation on the single trace imaging results, avoiding the enhancement of both clutter interference and effective signal concurrently by direct stacking. Second, the window threshold is set according to the GPR observation accuracy, and the effective signal in the MC result is retained as the abnormal region window, while the imaging results in the nonabnormal region are discarded, so as to suppress the clutter and retain the abnormal region information. Numerical experiments show that compared with the traditional RTM and total variation (TV) denoising method with cross correlation imaging conditions, the MCW imaging condition can accurately locate abnormal region, suppress clutter interference, and have the advantage of no loss of effective information, which greatly improves the imaging quality. Finally, the proposed method is applied to the measured data to verify the practicability and effectiveness in practical engineering applications. [ABSTRACT FROM AUTHOR]

Travertines are susceptible to fracturing/ cracking, making it difficult to extract large uncracked blocks of significant commercial value. In our study, we used the GPR – Ground Penetrating Radar and other geophysical methods (resistivity and seismic methods) to evaluate the degree of fracturing. Following the interpretation of the longitudinal and transversal GPR profiles, corroborated with the resistivities minima, led us to identify fractures and highly fracturing areas in the Carpinis quarry. In addition, using these combined methodologies and corroborating geophysical, geological, tectonic and geomorphological information creates the premises for an effective investigation of Carpinis quarry, which assists with optimising the mining process. [ABSTRACT FROM AUTHOR]

The construction of concrete structures for radiological protection in sanitary facilities requires a series of constructive conditions that guarantee safety. The influence of the correct bunkers design, wall thicknesses and the type of materials used is essential to ensure effective protection. The use of barite aggregate concrete is a common resource to improve the radiation attenuation capacity of concrete walls. The present study analyses the structure of a bunker during a renovation work, studying the construction characteristics of the chamber, the state of its elements, the characterization of materials, the identification of the emissions of the possible isotopes present, beta radioactive contamination and the measurement of equivalent dose rates at different points in the concrete. The results made it possible to determine the use of conventional concrete and barite concrete, the latter presenting a BaO content of around 40% and particularly low resistance values, not observing alteration processes in the materials. [ABSTRACT FROM AUTHOR]

In this study, ground penetration radar (GPR) was used to assess the internal defects and decay of structural old timber in buildings and compare it with the sound wood. For this purpose, twelve samples of three wood species of beech, oak and yew with dimensions of 120 × 60 × 400 mm, and as flat sawn were selected. Two samples from beech species with severe decay and two samples from oak species with mild decay were selected from old buildings. Sound and completely dry samples of these species (two samples from each species) were also obtained from forest trees as an indicator. Four yew samples without decay were selected only from the old buildings. Holes with a diameter of 2 and 8 mm were drilled in decayed and also two yew samples. The samples were scanned perpendicular to the fibers direction using a HF antenna of 2.3 GHz. The condition of data collection and processing were the same for all samples. After the initial data collection, in order to increase the resolution and better interpretation of the image, different filtration process was applied using image processing software Reflexw. The results showed that the relative dielectric coefficient was higher in decayed wood, and due to the difference in reflection coefficient between sound and decayed wood, they can be distinguished from each other. It was also possible to detect holes of 8 mm in oak and yew species. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

NeelagiriMaha Seya, constructed in the 2nd Century BC, is a colossal ruined stupa, situated in the woods of the Lahugala wildlife sanctuary in the Ampara district of the Eastern province, Sri Lanka. The stupa has a circumference of 182 m (600’) and a height of 22.6 m (74’). Presently, one side of the stupa has collapsed and some vertical cracks are visible on the eastern side of lower dome section of the stupa. Therefore, it is essential to carry out proper investigation on the current condition of the stupa before undertaking any major restoration work to restore the stupa to its original height. With this objective, a series of experimental testing and numerical modeling were performed. The foundation of the stupa was assessed using the Ground Penetration Radar (GPR) method. According to the GPR measurements, the stupa spreads 2.87 m away from the basal rings to a depth of 3 m from the existing ground level. It is apparent from GPR data, there exists gravel type rock below 3 m level from the existing ground and the stupa rests on matt gravel layer. Material properties of the ancient bricks of the stupa were evaluated with adequate laboratory testing. Test results showed that ancient bricks of the Neelagiri stupa have higher capacity than the modern bricks. Numerical analysis of the stupa was carried out using the general finite element software package SAP2000 to assess the stresses developed in the stupa due to its self-weight. The results showed that the stresses developed within the existing stupa due to its self-weight were well below the compressive strength and the tensile strength of the ancient bricks. Further, the study suggests two alternative shapes (bubble and paddy heap shapes) for completing the stupa restoration. A suitable shape is proposed for the restoration and the different restoration options have been analyzed with respect to structural performance along with the existing conditions.

DOI: 10.17014/ijog.5.2.137-160A detailed active fault study in Tarutung-Sarulla-Sipirok-Padangsidempuan was conducted based on their tectonic-morphological features using SRTM-30, 3D-visualization, and LIDAR data, combined with field and shallow geophysical surveys using the GPR method. Sumatran Fault Zone is bifurcated from the single major Sianok fault segment into two major branches: Angkola and Barumun-Toru Faults that run (sub) parallel to each other. In the studied area, they are merged gradually to become the Renun Fault. The total slip rates from Sianok to Renun segments are constant at about ~ 14 mm/year (13.8 ± 0.3 mm/yr on Renun and 13.7 ± 1.6 mm/yr on Sianok segments). In the bifurcation zone, it is partitioned into 9.3 ± 1.8 mm/yr slip on Toru, and about 4 - 5 mm/yr on Angkola segments. Based on field evidence supported by the seismicity and historical record, the Toru Fault appears to move continuously (creeping). This is crucial for understanding tectonics and its significance to hazard mitigations. Further investigations on Angkola and Toru Faults are crucial for mega installations of Sarulla Geothermal Power Plant, which is located in between Angkola and Toru Fault zones.

Voids underlying engineering re-enforced ground floor could be hazardous and may hinder proposed project objectives, if not adequately detected. Ground penetration radar is non-penetrative and non-destructive technique that is used successfully in this study to identify these cavities. The short radar pulses from antenna sources within microwave band of radio spectrum adequately images the subsurface to appreciable depth of interest (

Due to less visibility, underground facilities such as sewer pipelines are subjected to degradation until a major failure occurs. So, leakage detection of deteriorated underground sewer pipes is necessary to prevent expensive rehabilitation costs. The major causes of the frequent occurrence of ground subsidence and sewer leakage are excessive use of groundwater, reckless exploitation of natural resources, etc. In this study, the aerial thermal imaging (ATI) technique has been used to identify the leakage points in sewer pipelines by analyzing surface thermal diffusion behavior of the ground surface. Leakage is suspected at points of anomalous temperature variation. Then, ground-penetrating radar and closed-circuit television surveys have been carried out to strengthen the suspicion of sewer leakage. Irregular, erratic parabolic-shaped lines are observed at the points where the leakage is suspected through ATI. Finally, the test-pit excavation and simple cone penetration tests have been carried out which confirms the sewer leakage points. The leakage points are confirmed by a greater depth of penetration. The results of the cone penetration test carried out in E-21 and 23-24 sewer pipelines show that the depth of penetration at the leakage points is about 35 cm, which is greater than the depth of penetration at other points. So, it can be concluded that the aerial thermal imaging technique is an effective method to predict leakage in deteriorated underground sewer pipelines. [ABSTRACT FROM AUTHOR]

Copyright of Anuario do Instituto de Geociencias is the property of Universidade Federal do Rio de Janeiro, Instituto de Geociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The geological structures of two freshwater lakes (the Verkhnee and Vodoprovodnoe lakes) located near the White Sea Biological Station of Moscow State University (in the Kandalaksha Bay in the White Sea) are analyzed for the first time on the basis of ground penetration radar (GPR) data. The morphology of the top of the Archean basement, the structure of the Quaternary sedimentary cover, and the topography of the bottom were studied. Shallow marine sediments that overlie the Archean rocks and a complex of lacustrine-marsh sediments were identified, using the drilling data on the Quaternary deposits. We constructed structural schemes of the main reflecting horizons and schemes with isopachs for the main complexes. The specific electrical resistivity and absorption coefficient were calculated by GPR data, and the possibilities of the use of these parameters for the delineation of GPR facies were considered. [ABSTRACT FROM AUTHOR]

This paper describes a novel feed system for compact, wideband, high gain six-slot Vivaldi antenna arrays on a single substrate layer using a unique combination of power splitters based on binary T-junction power splitter topology, frequency-independent phase shifter, and a T-branch. The proposed antenna system consists of six Vivaldi antennas, three on the left, and three on the right arm. Each arm connects with T-junction power divider splitter topology, given that the right arm is linked through a frequency-independent phase shifter. Phase shifters ensure that the beam is symmetrical without splitting in a radiating plane so that highly directive radiation patterns occur. The optimal return losses (S-parameters) are well enriched by reforming Vivaldi’s feeding arms and optimizing Vivaldi slots and feeds. A novel feature of our design is that the antenna exhibits the arrangements of a T-junction power splitter with an out-of-phase feeding mechanism in one of the arms, followed by a T-branching feeding to even arrays of proper Vivaldi antenna arrangement contributing high realized gain and front-to-back ratio up to 14.12 dBi and 23.23 dB respectively applicable for not only ultra-wideband (UWB) application, also for sensing and position detecting. The high directivity over the entire UWB frequency band in both higher and lower frequency ranges ensures that the antenna can be used in microwave through-wall imaging along with resolution imaging for ground penetration radar (GPR) applications. The fabricated antenna parameters are in close agreement with the simulated and measured results and are deployed for the detection of targets inside the voids of the concrete brick.

Bendung Pasarbaru Irigasi Cisadane atau Bendung Pintu Air Sepuluh berlokasi di Kelurahan Koang Jaya, Kecamatan Karawaci, Tangerang. Bendung yang membentang sepanjang 110 meter di Kali Cisadane ini merupakan warisan kolonial Belanda, dibangun pada tahun 1923 dengan tujuan mengatur aliran sungai Cisadane untuk keperluan irigasi kota Tangerang. Upaya untuk monitoring kondisi aktual bendung dan sekitarnya dilakukan pengukuran Ground Penetrating Radar (GPR) atau Georadar untuk mengetahui kondisi dan karakteristik dibawah permukaan tanah. Pada dasarnya GPR bekerja dengan memanfaatkan pemantulan sinyal, pengolahan data dilakukan menggunakan software RADAN (RAdar Data ANalyzer) dan pada instalasi alat Georadar, digunakan antena 100 MHz. Hasil pengukuran georadar memperlihatkan anomali pada pertemuan struktur bendung dengan batas timbunan tanah aslinya. Pada lintasan arah memanjang dan melintang, variasi intensitas tidak menunjukkan kontras yang ekstrim di tubuh bendung. Tidak adanya perbedaan amplitudo mengindikasikan tidak adanya perbedaan kepadatan, artinya kondisi bawah permukaan bendung relatif homogen. Terdapat indikasi rembesan pada lintasan yang merupakan perpanjangan dari lintasan memanjang di kedalaman antara 14 m 22 m. Anomali ini, perlu diyakinkan dengan melakukan pengujian berupa pengeboran atau pengukuran lainnya.

Face perpendicular preconditioning is one of the mechanisms used in deep gold mines to transfer stress far ahead of the face on the development ends. Although face perpendicular pre-conditioning has been implemented in gold mines, rockbursts are still considered as the most problematic issue faced by deep gold mines. This paper investigates the effectiveness of face-perpendicular preconditioning that was developed for development ends in mechanized gold mines. The investigation comprised a comparison of four face and five face-perpendicular preconditioning holes in a deep gold mine. The results of the study indicated that five face-perpendicular preconditioning is more effective than four face-perpendicular preconditioning holes. The results were validated by adequate fracturing on the mining face, improvement of fracturing in the vicinity of the sockets and rapid decrease in the hangingwall fracturing. Ground Penetrating Radar, borehole periscope, seismic monitoring systems and numerical modelling were used to validate the effectiveness of the methods. [ABSTRACT FROM AUTHOR]

Continuously reinforced concrete pavement (CRCP) sections contain longitudinal and transverse reinforcement that spans the entire pavement section. This paper presents the investigation result of two CRCP sections that exhibited closely spaced cluster cracks. One of the CRCP sections was in relatively poor condition because of distress in the form of several punchouts. In the forensic pavement investigation conducted jointly by a research team and the Georgia Department of Transportation, both nondestructive and destructive tests were used to investigate CRCP performance. It was concluded that the cluster-cracking mechanism was related to material and environmental factors. It was also concluded that the relatively poor CRCP section experiencing punchouts was due to poor concrete compaction and other construction issues. A long-term monitoring program was recommended by the investigation team to further identify signs of punchout distress and provide any needed rehabilitation. [ABSTRACT FROM AUTHOR]

A detailed active fault study in Tarutung-Sarulla-Sipirok-Padangsidempuan was conducted based on their tectonic-morphological features using SRTM-30, 3D-visualization, and LIDAR data, combined with field and shallow geophysical surveys using the GPR method. Sumatran Fault Zone is bifurcated from the single major Sianok fault segment into two major branches: Angkola and Barumun-Toru Faults that run (sub) parallel to each other. In the studied area, they are merged gradually to become the Renun Fault. The total slip rates from Sianok to Renun segments are constant at about ~ 14 mm/year (13.8 ± 0.3 mm/yr on Renun and 13.7 ± 1.6 mm/yr on Sianok segments). In the bifurcation zone, it is partitioned into 9.3 ± 1.8 mm/yr slip on Toru, and about 4 - 5 mm/yr on Angkola segments. Based on field evidence supported by the seismicity and historical record, the Toru Fault appears to move continuously (creeping). This is crucial for understanding tectonics and its significance to hazard mitigations. Further investigations on Angkola and Toru Faults are crucial for mega installations of Sarulla Geothermal Power Plant, which is located in between Angkola and Toru Fault zones. [ABSTRACT FROM AUTHOR]

This study was conducted to estimate soil clay content in two depths using geophysical techniques (Ground Penetration Radar—GPR and Electromagnetic Induction—EMI) and ancillary variables (remote sensing and topographic data) in an arid region of the southeastern Iran. GPR measurements were performed throughout ten transects of 100 m length with the line spacing of 10 m, and the EMI measurements were done every 10 m on the same transect in six sites. Ten soil cores were sampled randomly in each site and soil samples were taken from the depth of 0–20 and 20–40 cm, and then the clay fraction of each of sixty soil samples was measured in the laboratory. Clay content was predicted using three different sets of properties including geophysical data, ancillary data, and a combination of both as inputs to multiple linear regressions (MLR) and decision tree-based algorithm of Chi-Squared Automatic Interaction Detection (CHAID) models. The results of the CHAID and MLR models with all combined data showed that geophysical data were the most important variables for the prediction of clay content in two depths in the study area. The proposed MLR model, using the combined data, could explain only 0.44 and 0.31% of the total variability of clay content in 0–20 and 20–40 cm depths, respectively. Also, the coefficient of determination (R 2 ) values for the clay content prediction, using the constructed CHAID model with the combined data, was 0.82 and 0.76 in 0–20 and 20–40 cm depths, respectively. CHAID models, therefore, showed a greater potential in predicting soil clay content from geophysical and ancillary data, while traditional regression methods (i.e. the MLR models) did not perform as well. Overall, the results may encourage researchers in using georeferenced GPR and EMI data as ancillary variables and CHAID algorithm to improve the estimation of soil clay content. [ABSTRACT FROM AUTHOR]

Ground-penetrating radar (GPR) has been widely used in detecting or imaging subsurface targets. In many applications such as archaeology, utility imaging, or landmine detection, three-dimensional (3D) images of the subsurface region is required for better understanding of the sensed medium. However, a high-resolution 3D image requires wideband data collection both in spatial and time/frequency domains. Match filtering is the main tool for generating subsurface images. Applying match filtering with the data acquisition impulse response for each possible voxel in the 3D region with the collected data requires both a tremendous amount of computer memory and computational complexity. Hence, it is very costly to obtain 3D GPR images in most of the applications although 3D images are very demanded results. In this paper, a new 3D imaging technique is proposed that will first decrease the memory requirements for 3D imaging with possible implications for less computational complexity. The proposed method uses the shifted impulse response of the targets that are on the same depth as a function of scanning position. This similarity of target responses for data dictionaries for only 2D target slices is constructed with twice the length in scanning directions and this 2D dictionary is mainly used for generating 3D images. The proposed method directly saves memory due to dimension reduction in dictionary generation and also decreases computational load. Simulation results show generated 3D images with the proposed technique. Comparisons in both memory and computational load with the standard backprojection show that the proposed technique offers advantages in both areas. [ABSTRACT FROM AUTHOR]

In this paper, regularized deconvolution is utilized to analyze GPR signal collected from thin asphalt pavement overlays of various mixtures and thicknesses on a test site. By applying regularized deconvolution and the L-curve method, the overlapped interface was identified in the signal. The thickness of the thin layer was predicted with maximum error of 4.2%, which is less than 1.5 mm, a value well below the layer tolerance during construction. The study shows that the algorithm based on regularized deconvolution is a simple and effective approach for processing GPR data collected from thin pavement layers to predict their thickness. [ABSTRACT FROM AUTHOR]