Borehole ground penetrating radar (GPR) was used to measure the temporal and spatial variability of soil water content under uniform wetting and drying conditions. Zero Offset Gather (ZOG) surveys were conducted before and during the uniform infiltration and the subsequent drainage experiments using the PuLseEKKO 100 borehole system with 200 MHz antennas in horizontal access tubes. Time domain reflectometry (TDR) data were collected from 10 vertical probes installed at 0. 1 m increments from 0.1 to 1.0 m below the ground surface. The TDR data were used as standard measures of soil water content to compare with the GPR estimated water content. The electromagnetic wave velocity along the survey profile at about 1 .0 m below the ground surface was estimated using ZOG data by picking the arrival time of the first event. Volumetric water content was calculated using a standard empirical relationship between velocity and water content for each ZOG location. Measured higher soil water content zones are potentially preferential flow areas and were observed in consistent locations throughout both the wetting and drying experiments. The radius of influence of the borehole GPR measurements was about 0.5 m determined theoretically and by comparing GPR and TDR data.
{"title":"Temporal and spatial variation of soil water content measured by borehole GPR under irrigation and drainage","authors":"L. Galagedara, G. Parkin, J. Redman, A. Endres","doi":"10.1117/12.462253","DOIUrl":"https://doi.org/10.1117/12.462253","url":null,"abstract":"Borehole ground penetrating radar (GPR) was used to measure the temporal and spatial variability of soil water content under uniform wetting and drying conditions. Zero Offset Gather (ZOG) surveys were conducted before and during the uniform infiltration and the subsequent drainage experiments using the PuLseEKKO 100 borehole system with 200 MHz antennas in horizontal access tubes. Time domain reflectometry (TDR) data were collected from 10 vertical probes installed at 0. 1 m increments from 0.1 to 1.0 m below the ground surface. The TDR data were used as standard measures of soil water content to compare with the GPR estimated water content. The electromagnetic wave velocity along the survey profile at about 1 .0 m below the ground surface was estimated using ZOG data by picking the arrival time of the first event. Volumetric water content was calculated using a standard empirical relationship between velocity and water content for each ZOG location. Measured higher soil water content zones are potentially preferential flow areas and were observed in consistent locations throughout both the wetting and drying experiments. The radius of influence of the borehole GPR measurements was about 0.5 m determined theoretically and by comparing GPR and TDR data.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"45 16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124473832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Existing positioning technologies used in conjunction with Ground Penetrating Radar (GPR) are generally too time-consuming or insufficiently accurate for high resolution, high frequency, 3-d structural investigations. In this paper we present an optical positioning system for use in GPR surveys. This system uses a camera mounted on the GPR antenna that takes video of the surface beneath it and calculates the relative motion of the antenna based on the differences between successive frames of video. Positioning using this technology can provide positioning accuracy to within several millimeters. Because the antenna can be moved free hand the procedure is orders of magnitude faster than surveying a grid of data points or laying out parallel lines and surveying each line with an antenna and odometer wheel. Time domain synthetic aperture radar algorithms reconstruct an image of the subsurface using this data. This is a new technology, but one which has potential for future research, improvements, and practical use.
{"title":"Improved optical positioning for GPR-based structure mapping","authors":"Kyle Doerksen","doi":"10.1117/12.462298","DOIUrl":"https://doi.org/10.1117/12.462298","url":null,"abstract":"Existing positioning technologies used in conjunction with Ground Penetrating Radar (GPR) are generally too time-consuming or insufficiently accurate for high resolution, high frequency, 3-d structural investigations. In this paper we present an optical positioning system for use in GPR surveys. This system uses a camera mounted on the GPR antenna that takes video of the surface beneath it and calculates the relative motion of the antenna based on the differences between successive frames of video. Positioning using this technology can provide positioning accuracy to within several millimeters. Because the antenna can be moved free hand the procedure is orders of magnitude faster than surveying a grid of data points or laying out parallel lines and surveying each line with an antenna and odometer wheel. Time domain synthetic aperture radar algorithms reconstruct an image of the subsurface using this data. This is a new technology, but one which has potential for future research, improvements, and practical use.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132699917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Characteristic features of ultra wide band (UWB) radio pulses reflection from a flat boundary between two lossy media with minimum contrast of dielectric permittivities are examined. The task has a high-priority for radar probing of upper soil layer and is connected with ranging of boundary between two media with close electrical parameters. This problem was solved many times for quasi-coherent signals and for transparent media. It was analyzed in [1] for UWB signals and monostatic GPR when difference of touching media electrical properties was pronounced (including a case of continuous vary of electrical properties near of boundary). Here we restrict ourselves in sharp border of homogeneous media in order to determine a generality of UWB signals reflection from low-contrast boundaries.
{"title":"Characteristic features of radar detection of the boundary between two dispersive media having minimum electrical contrast","authors":"N. Chubinsky, A. Krampuls, O. Shishkova","doi":"10.1117/12.462289","DOIUrl":"https://doi.org/10.1117/12.462289","url":null,"abstract":"Characteristic features of ultra wide band (UWB) radio pulses reflection from a flat boundary between two lossy media with minimum contrast of dielectric permittivities are examined. The task has a high-priority for radar probing of upper soil layer and is connected with ranging of boundary between two media with close electrical parameters. This problem was solved many times for quasi-coherent signals and for transparent media. It was analyzed in [1] for UWB signals and monostatic GPR when difference of touching media electrical properties was pronounced (including a case of continuous vary of electrical properties near of boundary). Here we restrict ourselves in sharp border of homogeneous media in order to determine a generality of UWB signals reflection from low-contrast boundaries.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132103595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Good drainage is important for healthy turf and proper playing surface. Because of the aesthetic and playability considerations, most of the drainage systems in a golf course were installed underground. With time golf green drainage systems can fail or become plugged up due to improper construction and/or management. Unfortunately, many golf green drainage maps are either unavailable or inaccurate. Locating a drainage system in a green is a very time consuming and difficult job. Many golf course superintendents invested many hours in locating these pipes when drainage problems occured. Correcting the drainage problems can be destructive to the green and expensive when location of the present system is unknown. The objective of the study was to locate and map the tile drainage system under a green using a ground penetrating radar. In the study, a SIR system 2000, with a 400 MHz antenna, ground penetrating radar (GPR) was used to scan a USGA green and a California style green. The experiment was conducted at the Stone Creek golf course(SCGC) Green No. 3 (a USGA green located at Makanda, IL) and Hickory Ridge golf course (HRGC) Green No. 2 (a California green, located in Carbondale, IL). The green at the SCGC was about 500 m 2 and the one at HRGC was close to 200 m 2 . Since sprinkler heads are fixed objects around the green, they were used as permanent reference points. The golf greens were divided to form a grid system and marked with flags 1 meter apart. The green was marked and scanned. In the measurement, the scanning was completed within fifteen minutes, but it took up to 45 minutes for laying out the grid of a 500 m 2 green. Results indicated that GPR could accurately locate the rooting zone thickness, depth of gravel layer, and drainage tiles in a golf green with minimum time and disturbance.
{"title":"Mapping golf green drainage systems and subsurface features using ground-penetrating radar","authors":"R. Boniak, S. Chong, S. Indorante, J. Doolittle","doi":"10.1117/12.462249","DOIUrl":"https://doi.org/10.1117/12.462249","url":null,"abstract":"Good drainage is important for healthy turf and proper playing surface. Because of the aesthetic and playability considerations, most of the drainage systems in a golf course were installed underground. With time golf green drainage systems can fail or become plugged up due to improper construction and/or management. Unfortunately, many golf green drainage maps are either unavailable or inaccurate. Locating a drainage system in a green is a very time consuming and difficult job. Many golf course superintendents invested many hours in locating these pipes when drainage problems occured. Correcting the drainage problems can be destructive to the green and expensive when location of the present system is unknown. The objective of the study was to locate and map the tile drainage system under a green using a ground penetrating radar. In the study, a SIR system 2000, with a 400 MHz antenna, ground penetrating radar (GPR) was used to scan a USGA green and a California style green. The experiment was conducted at the Stone Creek golf course(SCGC) Green No. 3 (a USGA green located at Makanda, IL) and Hickory Ridge golf course (HRGC) Green No. 2 (a California green, located in Carbondale, IL). The green at the SCGC was about 500 m 2 and the one at HRGC was close to 200 m 2 . Since sprinkler heads are fixed objects around the green, they were used as permanent reference points. The golf greens were divided to form a grid system and marked with flags 1 meter apart. The green was marked and scanned. In the measurement, the scanning was completed within fifteen minutes, but it took up to 45 minutes for laying out the grid of a 500 m 2 green. Results indicated that GPR could accurately locate the rooting zone thickness, depth of gravel layer, and drainage tiles in a golf green with minimum time and disturbance.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"35 17","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132124293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kwan-Ho Lee, N. Venkatarayalu, Chi-Chih Chen, F. Teixeira, R. Lee
Finite Differencing Time Domain (FDTD) modeling technique was developed as a tool to study GPR problem that could be very complex due to the antenna design, inhomogeneous soil and varieties of target types. The broadband, fully polarimetric horn-fed bowtie (HFB) antenna design (Chen, 1 997) was modeled as an example. Feeding cables, 3D antenna structure and tapered resistive loading were included. Calculated characteristics of the electrical properties of the HFB antenna in the entire 10 - 800 MHz range was obtained. Various technical issues involved in numerical modeling will be discussed.
{"title":"Numerical modeling development for characterizing complex GPR problems","authors":"Kwan-Ho Lee, N. Venkatarayalu, Chi-Chih Chen, F. Teixeira, R. Lee","doi":"10.1117/12.462287","DOIUrl":"https://doi.org/10.1117/12.462287","url":null,"abstract":"Finite Differencing Time Domain (FDTD) modeling technique was developed as a tool to study GPR problem that could be very complex due to the antenna design, inhomogeneous soil and varieties of target types. The broadband, fully polarimetric horn-fed bowtie (HFB) antenna design (Chen, 1 997) was modeled as an example. Feeding cables, 3D antenna structure and tapered resistive loading were included. Calculated characteristics of the electrical properties of the HFB antenna in the entire 10 - 800 MHz range was obtained. Various technical issues involved in numerical modeling will be discussed.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134399169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A series of experiments on asphalt pavement specimens with 1-GHz GPR system was conducted in the Connecticut Advanced Pavement (CAP) Laboratory. The objectives of these experiments are as follows. (1) Determining the dielectric property of the asphalt specimens; and (2) Correlating electromagnetic (EM) properties with void ratio and asphalt binder content ratio of asphalt pavement specimens. Results of this study can be used as the baseline to calibrate GPR field surveys for pavement assessment, as well as an indirect means to monitor the compaction process. The travel time for direct and reflected phases are the fundamental information for computing EM wave velocity. Supplemented by pre-existing information on geometry, void ratio, composition measured by other means, we were able to compute the dielectric constant of 30 pavement specimens. The major conclusions from these experiments are as follows. (1) In general EM wave velocity is highest in dry conditions, intermediate in frozen, and lowest in water-saturated conditions; Correspondingly, the dielectric constant is smallest in dry conditions, intermediate in frozen, and highest in water-saturated conditions. (2) EM wave velocity increases slightly with the increase of void ratio for dry samples. In contrast, it decreases significantly with a void ratio increase in water-saturated conditions. Correspondingly, the dielectric constant decreases noticeably with an increasing void ratio in dry conditions, and increases appreciably in saturated conditions. (3) The changes of EM velocity and dielectric constant for dry and saturated conditions can be predicted by the effective medium theory for porous media. (4) When the dielectric constant of the pore material is taken as the value of fresh water ice, the change of EM velocity and dielectric constant for the asphalt pavement specimens in frozen conditions cannot be correctly predicted with the effective medium theory. This implies that the pore water was not completely frozen when GPR measurement was taken. There are no significant changes in dielectric constant for dry and frozen conditions. (5) Variations in EM velocity and dielectric constant with asphalt binder ratio imply that a low asphalt ratio corresponds to a high void ratio so that in the lower end of the asphalt ratio, EM velocity has maximum fluctuation among the different conditions.
{"title":"Dielectric property of asphalt pavement specimens in dry, water-saturated, and frozen conditions","authors":"Lanbo Liu, T. Guo","doi":"10.1117/12.462222","DOIUrl":"https://doi.org/10.1117/12.462222","url":null,"abstract":"A series of experiments on asphalt pavement specimens with 1-GHz GPR system was conducted in the Connecticut Advanced Pavement (CAP) Laboratory. The objectives of these experiments are as follows. (1) Determining the dielectric property of the asphalt specimens; and (2) Correlating electromagnetic (EM) properties with void ratio and asphalt binder content ratio of asphalt pavement specimens. Results of this study can be used as the baseline to calibrate GPR field surveys for pavement assessment, as well as an indirect means to monitor the compaction process. The travel time for direct and reflected phases are the fundamental information for computing EM wave velocity. Supplemented by pre-existing information on geometry, void ratio, composition measured by other means, we were able to compute the dielectric constant of 30 pavement specimens. The major conclusions from these experiments are as follows. (1) In general EM wave velocity is highest in dry conditions, intermediate in frozen, and lowest in water-saturated conditions; Correspondingly, the dielectric constant is smallest in dry conditions, intermediate in frozen, and highest in water-saturated conditions. (2) EM wave velocity increases slightly with the increase of void ratio for dry samples. In contrast, it decreases significantly with a void ratio increase in water-saturated conditions. Correspondingly, the dielectric constant decreases noticeably with an increasing void ratio in dry conditions, and increases appreciably in saturated conditions. (3) The changes of EM velocity and dielectric constant for dry and saturated conditions can be predicted by the effective medium theory for porous media. (4) When the dielectric constant of the pore material is taken as the value of fresh water ice, the change of EM velocity and dielectric constant for the asphalt pavement specimens in frozen conditions cannot be correctly predicted with the effective medium theory. This implies that the pore water was not completely frozen when GPR measurement was taken. There are no significant changes in dielectric constant for dry and frozen conditions. (5) Variations in EM velocity and dielectric constant with asphalt binder ratio imply that a low asphalt ratio corresponds to a high void ratio so that in the lower end of the asphalt ratio, EM velocity has maximum fluctuation among the different conditions.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122647243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During 2000, Hager GeoScience, Inc. (HGI) performed a geophysical survey at a former paint factory site outside Boston, Massachusetts at which lead- and chromium-containing paint residue was known to be present in the subsurface. The goal was to determine the applicability of electromagnetic methods to mapping variations in the concentrations of pigment in fill. GPR and EM terrain conductivity techniques were tested in areas of known contamination and then applied to a nearby area under investigation. A GPR survey was performed along traverses at 2-foot spacing, enabling the use of 3D modeling techniques. Survey results were presented as GPR 3D and filled color contour EM plots. Slices at increasing depths through the GPR 3D plots revealed spatially localized high-amplitude zones of pigment concentration and attenuated zones of normal fill. The shallow depth slices showed that the pigment was most concentrated between 10 and 15 feet. Slices through the 3D plots at greater depths showed that in some areas the attenuated zones of normal fill reached depths of over 30 feet, consistent with fill depths in boring logs provided by the client.
{"title":"Application of 3D GPR plots to interpreting distribution of paint pigment contamination","authors":"J. Hager, M. Carnevale","doi":"10.1117/12.462237","DOIUrl":"https://doi.org/10.1117/12.462237","url":null,"abstract":"During 2000, Hager GeoScience, Inc. (HGI) performed a geophysical survey at a former paint factory site outside Boston, Massachusetts at which lead- and chromium-containing paint residue was known to be present in the subsurface. The goal was to determine the applicability of electromagnetic methods to mapping variations in the concentrations of pigment in fill. GPR and EM terrain conductivity techniques were tested in areas of known contamination and then applied to a nearby area under investigation. A GPR survey was performed along traverses at 2-foot spacing, enabling the use of 3D modeling techniques. Survey results were presented as GPR 3D and filled color contour EM plots. Slices at increasing depths through the GPR 3D plots revealed spatially localized high-amplitude zones of pigment concentration and attenuated zones of normal fill. The shallow depth slices showed that the pigment was most concentrated between 10 and 15 feet. Slices through the 3D plots at greater depths showed that in some areas the attenuated zones of normal fill reached depths of over 30 feet, consistent with fill depths in boring logs provided by the client.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120950157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The OSU/ESL GPR systems have been applied to the detection and classification of buried unexploded ordnance (UXO) for years. It has evolved from an impulse and single-polarization (cross-polarization) system utilizing complex natural resonance (CNR) feature to the recent step-frequency and fully polarimetric system utilizing CNR, polarization and scattering features. Significant progresses in measurement techniques, feature extraction algorithms and classification rules have been made during the past three years under the support US DoD ESTCP program. These important progresses were motivated by field data collected at government test sites such as Tyndall AFB (1999), Blossom Point (2000) and Jefferson Proving Ground (2001). This paper briefly describes these progresses and the motivations behind them.
{"title":"Evolution of buried UXO classification using broadband fully polarimetric GPR","authors":"Chi-Chih Chen, M. Higgins, K. O'Neill","doi":"10.1117/12.462313","DOIUrl":"https://doi.org/10.1117/12.462313","url":null,"abstract":"The OSU/ESL GPR systems have been applied to the detection and classification of buried unexploded ordnance (UXO) for years. It has evolved from an impulse and single-polarization (cross-polarization) system utilizing complex natural resonance (CNR) feature to the recent step-frequency and fully polarimetric system utilizing CNR, polarization and scattering features. Significant progresses in measurement techniques, feature extraction algorithms and classification rules have been made during the past three years under the support US DoD ESTCP program. These important progresses were motivated by field data collected at government test sites such as Tyndall AFB (1999), Blossom Point (2000) and Jefferson Proving Ground (2001). This paper briefly describes these progresses and the motivations behind them.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127305337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Pleistocene push moraines in the Netherlands were formed during the penultimate glaciation. The data presented were collected at the eastern Veluwe ridge. Based on extensive 50 MHz ground-penetrating radar surveying, three architectural styles are distinguished. In order to deduce relationships between these structural styles, sediment facies and radar facies, the GPR surveys were complimented by data from continuously cored boreholes. Additional borehole logging served the same purpose. In this paper GPR facies of two glaciotectonic styles are analyzed: gently folded parallel fluvial sequences and imbricated thrusts in fluvial sequences. It is shown that coherent reflectors, using 50 MHz central frequencies, can be related to relatively thin (8-20 cm) fine-grained sedimentary layers. These layers are not necessarily clay, but more often silty fine sand. The presented radar facies show strong relationships with sedimentary facies as evidenced by lithology in the core and the accompanying gamma-ray borehole logs The result leads to the conclusion that ground-penetrating radar is an excellent tool for mapping the complex architecture of Pleistocene push moraines and that a combination of techniques is particularly powerful.
{"title":"Comparison of ground-penetrating radar facies and sediment characteristics in a Pleistocene push moraine in the Netherlands","authors":"M. Bakker","doi":"10.1117/12.462304","DOIUrl":"https://doi.org/10.1117/12.462304","url":null,"abstract":"The Pleistocene push moraines in the Netherlands were formed during the penultimate glaciation. The data presented were collected at the eastern Veluwe ridge. Based on extensive 50 MHz ground-penetrating radar surveying, three architectural styles are distinguished. In order to deduce relationships between these structural styles, sediment facies and radar facies, the GPR surveys were complimented by data from continuously cored boreholes. Additional borehole logging served the same purpose. In this paper GPR facies of two glaciotectonic styles are analyzed: gently folded parallel fluvial sequences and imbricated thrusts in fluvial sequences. It is shown that coherent reflectors, using 50 MHz central frequencies, can be related to relatively thin (8-20 cm) fine-grained sedimentary layers. These layers are not necessarily clay, but more often silty fine sand. The presented radar facies show strong relationships with sedimentary facies as evidenced by lithology in the core and the accompanying gamma-ray borehole logs The result leads to the conclusion that ground-penetrating radar is an excellent tool for mapping the complex architecture of Pleistocene push moraines and that a combination of techniques is particularly powerful.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126342892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The firn regime of Antarctica extends 60-100 m deep and contains at least the last 200 years of snow deposition. As part of a program to study the influence of industrialization on antarctic climate and glacial mass balance, I have acquired about 3000 km of profiles of the stratigraphy of this regime in West Antarctica using 400-MHz GPR. Here, sections of these deeper profiles are presented to show the performance that can be achieved with commercial-grade radar in polar firn and to show some of the horizon characteristics. The profiles show 1) distinct reflections that are probably thin layer responses, 2) deepest penetration to about 130 m, 3) long-distance horizon continuity (as great as 500 km), and 4) folding caused by tectonic compression. The continuity, the increase of reflection strength with depth, and the slow variation of strength with distance suggest that the reflections are caused by chemical impurities and not density contrasts. Continuity will improve with faster trace acquisition. Resolution may not improve at higher frequencies because horizons may blur from antenna motion and horizon irregularities.
{"title":"Stratigraphic profiling of Antarctic firn with 400-MHz GPR at 1500 ns","authors":"S. Arcone","doi":"10.1117/12.462269","DOIUrl":"https://doi.org/10.1117/12.462269","url":null,"abstract":"The firn regime of Antarctica extends 60-100 m deep and contains at least the last 200 years of snow deposition. As part of a program to study the influence of industrialization on antarctic climate and glacial mass balance, I have acquired about 3000 km of profiles of the stratigraphy of this regime in West Antarctica using 400-MHz GPR. Here, sections of these deeper profiles are presented to show the performance that can be achieved with commercial-grade radar in polar firn and to show some of the horizon characteristics. The profiles show 1) distinct reflections that are probably thin layer responses, 2) deepest penetration to about 130 m, 3) long-distance horizon continuity (as great as 500 km), and 4) folding caused by tectonic compression. The continuity, the increase of reflection strength with depth, and the slow variation of strength with distance suggest that the reflections are caused by chemical impurities and not density contrasts. Continuity will improve with faster trace acquisition. Resolution may not improve at higher frequencies because horizons may blur from antenna motion and horizon irregularities.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128661362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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