The U.S. Geological Survey is developing a directional borehole radar (DBOR) tool for mapping fractures, lithologic changes, and underground utility and void detection. An important part of the development of the DBOR tool is data analysis and visualization, with the aim of making the software graphical user interface (GUI) intuitive and easy to use. The DBOR software system consists of a suite of signal and image processing routines written in Research Systems' Interactive Data Language (IDL). The software also serves as a front-end to many widely accepted Colorado School of Mines Center for Wave Phenomena (CWP) Seismic UNIX (SU) algorithms (Cohen and Stockwell, 2001). Although the SU collection runs natively in a UNIX environment, our system seamlessly emulates a UNIX session within a widely used PC operating system (MicroSoft Windows) using GNU tools (Noer, 1998). Examples are presented of laboratory data acquired with the prototype tool from two different experimental settings. The first experiment imaged plastic pipes in a macro-scale sand tank. The second experiment monitored the progress of an invasion front resulting from oil injection. Finally, challenges to further development and planned future work are discussed.
{"title":"Advances in directional borehole radar data analysis and visualization","authors":"David V. Smith, P. Brown","doi":"10.1117/12.462230","DOIUrl":"https://doi.org/10.1117/12.462230","url":null,"abstract":"The U.S. Geological Survey is developing a directional borehole radar (DBOR) tool for mapping fractures, lithologic changes, and underground utility and void detection. An important part of the development of the DBOR tool is data analysis and visualization, with the aim of making the software graphical user interface (GUI) intuitive and easy to use. The DBOR software system consists of a suite of signal and image processing routines written in Research Systems' Interactive Data Language (IDL). The software also serves as a front-end to many widely accepted Colorado School of Mines Center for Wave Phenomena (CWP) Seismic UNIX (SU) algorithms (Cohen and Stockwell, 2001). Although the SU collection runs natively in a UNIX environment, our system seamlessly emulates a UNIX session within a widely used PC operating system (MicroSoft Windows) using GNU tools (Noer, 1998). Examples are presented of laboratory data acquired with the prototype tool from two different experimental settings. The first experiment imaged plastic pipes in a macro-scale sand tank. The second experiment monitored the progress of an invasion front resulting from oil injection. Finally, challenges to further development and planned future work are discussed.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"28 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":"123106902","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}
Locating clandestine burials of human remains has long-challenged law-enforcement officials investigating criminal activity, and continues to confront scientific disciplines in finding well-defined procedures. Forensic specialists and law enforcement agencies have noted that multidisciplinary search efforts are becoming more of a necessity in searching for buried remains. Collaborative research at The University of Tennessee's Anthropological Research Facility (ARF) in Knoxville supports this concept. We are correlating ground-penetrating radar (GPR) imaging with postmortem processes. Decompositional stages and rate imagery are presented that utilize sweep-frequency radar and time-elapsed imaging. Greater accuracy in predicting clandestine burials using dynamic GPR anomaly detection will reduce widespread excavations and may better assist law-enforcement personnel in obtaining site-specific search warrants.
{"title":"Searching for concealed human remains using GPR imaging of decomposition","authors":"M. L. Miller, R. S. Freeland, S. Koppenjan","doi":"10.1117/12.462240","DOIUrl":"https://doi.org/10.1117/12.462240","url":null,"abstract":"Locating clandestine burials of human remains has long-challenged law-enforcement officials investigating criminal activity, and continues to confront scientific disciplines in finding well-defined procedures. Forensic specialists and law enforcement agencies have noted that multidisciplinary search efforts are becoming more of a necessity in searching for buried remains. Collaborative research at The University of Tennessee's Anthropological Research Facility (ARF) in Knoxville supports this concept. We are correlating ground-penetrating radar (GPR) imaging with postmortem processes. Decompositional stages and rate imagery are presented that utilize sweep-frequency radar and time-elapsed imaging. Greater accuracy in predicting clandestine burials using dynamic GPR anomaly detection will reduce widespread excavations and may better assist law-enforcement personnel in obtaining site-specific search warrants.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"26 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":"124933063","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}
Ground-penetrating radar (GPR) and downhole soil moisture readings have been conducted over a former landfill to the north of Adelaide, South Australia, in order to determine and map the thickness and lateral extents of the landfill capping layer over the underlying domestic waste. The study site, Cavan Landfill, is a former landfill undergoing a remediation program including landfill gas extraction and capping. Through the integration of the two data sets, GPR and soil-moisture, accurate information on the thickness and continuity of the capping layer on the landfill has been obtained. Six GPR profiles were collected using a Noggin 500 MHz unit. A time window of 50 nanoseconds was set to give maximum resolution between 0.8 metres and 2.4 metres. Ten shallow wells were installed for characterisation by the 'Diviner 2000' capacitance soil moisture probe along the periphery of the area. Moisture readings were collected in mmH 2 O over time at 10 centimetre intervals up to 1.6 metres in depth. Moisture profiles were superimposed on the GPR profiles for interpretation. The results give accurate information on the capping layer, the degree of heterogeneity and moisture level fluctuations.
{"title":"Integration of ground-penetrating radar and downhole soil moisture data to map the thickness and continuity of landfill capping","authors":"Tony S. Faulkner, P. Mill, Kyle T. Moyle","doi":"10.1117/12.462242","DOIUrl":"https://doi.org/10.1117/12.462242","url":null,"abstract":"Ground-penetrating radar (GPR) and downhole soil moisture readings have been conducted over a former landfill to the north of Adelaide, South Australia, in order to determine and map the thickness and lateral extents of the landfill capping layer over the underlying domestic waste. The study site, Cavan Landfill, is a former landfill undergoing a remediation program including landfill gas extraction and capping. Through the integration of the two data sets, GPR and soil-moisture, accurate information on the thickness and continuity of the capping layer on the landfill has been obtained. Six GPR profiles were collected using a Noggin 500 MHz unit. A time window of 50 nanoseconds was set to give maximum resolution between 0.8 metres and 2.4 metres. Ten shallow wells were installed for characterisation by the 'Diviner 2000' capacitance soil moisture probe along the periphery of the area. Moisture readings were collected in mmH 2 O over time at 10 centimetre intervals up to 1.6 metres in depth. Moisture profiles were superimposed on the GPR profiles for interpretation. The results give accurate information on the capping layer, the degree of heterogeneity and moisture level fluctuations.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"14 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":"115029345","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}
Wessel J. A. van Brakel, Marius D. van Wyk, M. Rutschlin, J. Cloete
Unexpectedly weak signal levels, in both radar and cross-hole modes, were obtained during a recent VHF borehole radar experiment in an arid, alluvial environment. 1 An investigation revealed that the kaolinitic strata, which hosted the vertical boreholes, were moistened by drilling fluid during site preparation. It was therefore conjectured that the weak received signals were due to attenuation caused by wet, conductive annuli surrounding the boreholes in an otherwise dry medium. To examine this premise, the VHF electrical properties (permittivity and conductivity) of representative dry and wet samples from the different strata were measured. These data were then used in a 3D, electrodynamic Finite Difference Time Domain (FDTD) code to model different annular configurations of dry and wet strata in and around boreholes of different dimensions. In the model, a 1.2 m center-fed dipole was placed coaxially in the various boreholes and excited by a Gaussian pulse. This allowed quantification of the reduction in electric field strength due to the wet drilling technique. The results correspond well with the measured attenuation observed during the borehole radar surveys. The paper concludes with recommendations for the preparation of borehole radar surveys of paleochannels covered by kaolinitic strata.
{"title":"Effect of wet drilling in kaolinitic strata on borehole radar performance","authors":"Wessel J. A. van Brakel, Marius D. van Wyk, M. Rutschlin, J. Cloete","doi":"10.1117/12.462212","DOIUrl":"https://doi.org/10.1117/12.462212","url":null,"abstract":"Unexpectedly weak signal levels, in both radar and cross-hole modes, were obtained during a recent VHF borehole radar experiment in an arid, alluvial environment. 1 An investigation revealed that the kaolinitic strata, which hosted the vertical boreholes, were moistened by drilling fluid during site preparation. It was therefore conjectured that the weak received signals were due to attenuation caused by wet, conductive annuli surrounding the boreholes in an otherwise dry medium. To examine this premise, the VHF electrical properties (permittivity and conductivity) of representative dry and wet samples from the different strata were measured. These data were then used in a 3D, electrodynamic Finite Difference Time Domain (FDTD) code to model different annular configurations of dry and wet strata in and around boreholes of different dimensions. In the model, a 1.2 m center-fed dipole was placed coaxially in the various boreholes and excited by a Gaussian pulse. This allowed quantification of the reduction in electric field strength due to the wet drilling technique. The results correspond well with the measured attenuation observed during the borehole radar surveys. The paper concludes with recommendations for the preparation of borehole radar surveys of paleochannels covered by kaolinitic strata.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"4 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":"128982400","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}
G. Grandjean, P. Paillou, N. Baghdadi, E. Heggy, T. August, J. Achache
We study the capabilities of low frequency radar systems to sound the subsurface in arid countries. This approach is based on the coupling between two complementary radar techniques: the airborne Synthetic Aperture Radar (SAR) used in L-band (1.2 GHz) for imaging large scale subsurface structures, and the Ground-Penetrating Radar (GPR) used between 500 and 900 MHz for sounding soils at a local scale, from the surface down to several meters. In this paper,. we first recall the results obtained on the Pyla dune (France). This site is a bare sandy area presenting large subsurface structures (paleosoils) at varying depths. A polarimetric analysis of airborne SAR data, as well as the GPR sounding experiment, shows that subsurface scattering occurs at several places. The SAR penetration depth is estimated by inverting a simple scattering model for which the subsurface structure, i.e. geometric and dielectric properties, is determined by the GPR data analysis. The recent results obtained on the well-known site of Bir Safsaf (southern Egypt) are then presented. The comparison between L-band SAR and GPR sections shows that penetration effects occur in many places, revealing rich subsurface structures. These results suggest that airborne radar systems in a lower frequency range (P-L band) should be able to detect soil structures down to several meters, leading to innovative Earth observation systems for geological and hydrogeological mapping in arid regions.
{"title":"Subsurface imaging with low-frequency SAR field validation in France and Egypt using ground-penetrating radar","authors":"G. Grandjean, P. Paillou, N. Baghdadi, E. Heggy, T. August, J. Achache","doi":"10.1117/12.462247","DOIUrl":"https://doi.org/10.1117/12.462247","url":null,"abstract":"We study the capabilities of low frequency radar systems to sound the subsurface in arid countries. This approach is based on the coupling between two complementary radar techniques: the airborne Synthetic Aperture Radar (SAR) used in L-band (1.2 GHz) for imaging large scale subsurface structures, and the Ground-Penetrating Radar (GPR) used between 500 and 900 MHz for sounding soils at a local scale, from the surface down to several meters. In this paper,. we first recall the results obtained on the Pyla dune (France). This site is a bare sandy area presenting large subsurface structures (paleosoils) at varying depths. A polarimetric analysis of airborne SAR data, as well as the GPR sounding experiment, shows that subsurface scattering occurs at several places. The SAR penetration depth is estimated by inverting a simple scattering model for which the subsurface structure, i.e. geometric and dielectric properties, is determined by the GPR data analysis. The recent results obtained on the well-known site of Bir Safsaf (southern Egypt) are then presented. The comparison between L-band SAR and GPR sections shows that penetration effects occur in many places, revealing rich subsurface structures. These results suggest that airborne radar systems in a lower frequency range (P-L band) should be able to detect soil structures down to several meters, leading to innovative Earth observation systems for geological and hydrogeological mapping in arid regions.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"11 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":"130407057","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}
Information extracted from crosshole georadar data has been used to characterize a gravel- and sand-dominated aquifer. Inversions of direct arrival traveltimes and amplitudes have provided electromagnetic velocity and attenuation tomograms that have allowed critical hydrological structures and parameters to be determined. An integrated interpretation of the velocity and attenuation tomograms was performed via a k-means cluster analysis. As a result of this multivariate statistical analysis, major trends in the relationship between velocity and attenuation were identified, thus enabling us to outline the major hydrostratigraphicu nits ofthe surveyedd eposit.
{"title":"Combining cross-hole georadar velocity and attenuation tomography for site characterization: a case study in an unconsolidated aquifer","authors":"J. Tronicke, H. Paasche, K. Holliger, A. Green","doi":"10.1117/12.462250","DOIUrl":"https://doi.org/10.1117/12.462250","url":null,"abstract":"Information extracted from crosshole georadar data has been used to characterize a gravel- and sand-dominated aquifer. Inversions of direct arrival traveltimes and amplitudes have provided electromagnetic velocity and attenuation tomograms that have allowed critical hydrological structures and parameters to be determined. An integrated interpretation of the velocity and attenuation tomograms was performed via a k-means cluster analysis. As a result of this multivariate statistical analysis, major trends in the relationship between velocity and attenuation were identified, thus enabling us to outline the major hydrostratigraphicu nits ofthe surveyedd eposit.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"25 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":"123855063","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 villa of the Roman Emperor Marcus Ulpius Trajanus (AD52-117) was built in Arcinazzo Italy, approximately 55 km northeast of Rome. Today, the only remains left standing at the site are public building entrances comprising a small portion of the entire site. As part of an ongoing study to rescue this national archaeological treasure, an extensive grid system was laid out and high-resolution GPR surveys using sub-meter profile spacings were conducted. Amplitude time slice analysis indicates that many structural foundations of the villa are still well preserved below the ground surface. Time slices below 40 ns in one area reveal several large mushroom shaped structures enclosed within a large building over 100 meters in length. These rounded structures are believed to be dipping pools within the bathhouse to the villa. At a location west of the bathhouse, a large oval shaped anomaly 45 meters along its major axis was discovered. Several intermediate time slices show a very faint overlapping oval reflection with a different orientation. The fainter anomaly may indicate the initial construction geometry was adjusted soon after construction began on the site for a garden pond or outdoor pooi area. The data are also examined using fast animation of the radar time slices . In this dynamic display of the datasets, several other information such as overlying topsoil depths across the site, and the relationship of structural anomalies at different levels, can be easily visualized when compared to normal static displays of radar data.
{"title":"GPR time slice images of the Villa of Emperor Trajanus, Arcinazzo, Italy (AD 52-117)","authors":"D. Goodman, S. Piro, Y. Nishimura","doi":"10.1117/12.462205","DOIUrl":"https://doi.org/10.1117/12.462205","url":null,"abstract":"The villa of the Roman Emperor Marcus Ulpius Trajanus (AD52-117) was built in Arcinazzo Italy, approximately 55 km northeast of Rome. Today, the only remains left standing at the site are public building entrances comprising a small portion of the entire site. As part of an ongoing study to rescue this national archaeological treasure, an extensive grid system was laid out and high-resolution GPR surveys using sub-meter profile spacings were conducted. Amplitude time slice analysis indicates that many structural foundations of the villa are still well preserved below the ground surface. Time slices below 40 ns in one area reveal several large mushroom shaped structures enclosed within a large building over 100 meters in length. These rounded structures are believed to be dipping pools within the bathhouse to the villa. At a location west of the bathhouse, a large oval shaped anomaly 45 meters along its major axis was discovered. Several intermediate time slices show a very faint overlapping oval reflection with a different orientation. The fainter anomaly may indicate the initial construction geometry was adjusted soon after construction began on the site for a garden pond or outdoor pooi area. The data are also examined using fast animation of the radar time slices . In this dynamic display of the datasets, several other information such as overlying topsoil depths across the site, and the relationship of structural anomalies at different levels, can be easily visualized when compared to normal static displays of radar data.","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":"124194105","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}
R. Birken, Douglas E. Miller, M. Burns, P. Albats, Robert Casadonte, R. Deming, Tony Derubeis, T. Hansen, M. Oristaglio
Ground-penetrating imaging radar ("GPiR") combines standard GPR with accurate positioning and advanced signal processing to create three-dimensional (3D) images of the shallow subsurface. These images can reveal soil conditions and buried infrastructure typically down to depths of about 2-3m with high resolution. A commercial GPiR called the CART Imaging System, which was designed for mapping urban infrastructure, has been developed. The CART system uses a radar array consisting of 17 antennas (9 transmitters and 8 receivers) that cover a 2m swath on the ground and can collect data while moving at speeds up to about 1 km/h. A laser theodolite tracks the position of the array during operation. The system collects enough data in a single pass to form a 3D image beneath its track; side-by-side passes are stitched together to create a seamless image of the subsurface. GPiR was first tested on a large scale in a project that mapped an area of approximately 12,000m2 in the south Bronx in four nights. Positions of surface features were also surveyed with the theodolite to provide a local reference grid. Final images were visualized with large-scale maps and electronic movies that scroll through the 3D data volume and show the enormous complexity of the subsurface in large cities.
{"title":"Efficient large-scale underground utility mapping in New York City using a multichannel ground-penetrating imaging radar system","authors":"R. Birken, Douglas E. Miller, M. Burns, P. Albats, Robert Casadonte, R. Deming, Tony Derubeis, T. Hansen, M. Oristaglio","doi":"10.1117/12.462307","DOIUrl":"https://doi.org/10.1117/12.462307","url":null,"abstract":"Ground-penetrating imaging radar (\"GPiR\") combines standard GPR with accurate positioning and advanced signal processing to create three-dimensional (3D) images of the shallow subsurface. These images can reveal soil conditions and buried infrastructure typically down to depths of about 2-3m with high resolution. A commercial GPiR called the CART Imaging System, which was designed for mapping urban infrastructure, has been developed. The CART system uses a radar array consisting of 17 antennas (9 transmitters and 8 receivers) that cover a 2m swath on the ground and can collect data while moving at speeds up to about 1 km/h. A laser theodolite tracks the position of the array during operation. The system collects enough data in a single pass to form a 3D image beneath its track; side-by-side passes are stitched together to create a seamless image of the subsurface. GPiR was first tested on a large scale in a project that mapped an area of approximately 12,000m2 in the south Bronx in four nights. Positions of surface features were also surveyed with the theodolite to provide a local reference grid. Final images were visualized with large-scale maps and electronic movies that scroll through the 3D data volume and show the enormous complexity of the subsurface in large cities.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"20 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":"116255433","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}
Polarimetric measurements provide additional information to aid in determining the geometric and physical properties of sub-surface targets. In this paper algorithms are derived to extract polarimetric target descriptors from a Stepped Frequency Continuous Wave Ground Penetrating Radar (SFCW GPR) data. The algorithm uses the multi-snapshot Matrix Pencil-of-function Method, to estimate the parameters of a fully polarimatric SFCW GPR model developed in this paper. The processing is applied to both simulated and laboratory measurements, and the results demonstrate the validity of this technique.
{"title":"Polarimetric model for a stepped-frequency continuous-wave ground-penetrating radar","authors":"A. Langman, M. Inggs","doi":"10.1117/12.462291","DOIUrl":"https://doi.org/10.1117/12.462291","url":null,"abstract":"Polarimetric measurements provide additional information to aid in determining the geometric and physical properties of sub-surface targets. In this paper algorithms are derived to extract polarimetric target descriptors from a Stepped Frequency Continuous Wave Ground Penetrating Radar (SFCW GPR) data. The algorithm uses the multi-snapshot Matrix Pencil-of-function Method, to estimate the parameters of a fully polarimatric SFCW GPR model developed in this paper. The processing is applied to both simulated and laboratory measurements, and the results demonstrate the validity of this technique.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"111 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":"114712747","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 new multistatic phase-based GPR technique for precise characterization of rough surfaces in three-dimensional space and for ingenious detection of weak-contrast scattering objects buried beneath the air-ground interface is proposed. The technique has been tested by the data measured using wideband stepped-frequency GPR over the compound surface, which consists of flat surface, several small isolated areas of rough surfaces and areas with shallowly buried plastic objects as surrogate landmines. The maximum height of rough surfaces and the maximum depth of buried dielectric objects are made less than one practical range resolution cell. The buried objects have low dielectric contrast against their surrounding medium in the frequency range used in the measurements. The antennas adopted are broadband, have low gain and wide beamwidth. The results show good agreement with the actual distribution of the discrete scattering objects such as buried plastic M14 type mine (5 cm in diameter and 4.2 cm in height) and with the real shape of continuous scatterers (rough surfaces). Moreover a new spatial-based processing method is described for noise reduction and the measurement errors. The processed results show better accuracy and focusing patterns than those previously obtained. This technique neither requires a priori knowledge about the background medium nor needs any pure background measurement.
{"title":"Near-range phase-based detection of small subsurface objects and characterization of local rough surfaces with bistatic wide-beamwidth antennas","authors":"B. Sai, L. Ligthart","doi":"10.1117/12.462314","DOIUrl":"https://doi.org/10.1117/12.462314","url":null,"abstract":"A new multistatic phase-based GPR technique for precise characterization of rough surfaces in three-dimensional space and for ingenious detection of weak-contrast scattering objects buried beneath the air-ground interface is proposed. The technique has been tested by the data measured using wideband stepped-frequency GPR over the compound surface, which consists of flat surface, several small isolated areas of rough surfaces and areas with shallowly buried plastic objects as surrogate landmines. The maximum height of rough surfaces and the maximum depth of buried dielectric objects are made less than one practical range resolution cell. The buried objects have low dielectric contrast against their surrounding medium in the frequency range used in the measurements. The antennas adopted are broadband, have low gain and wide beamwidth. The results show good agreement with the actual distribution of the discrete scattering objects such as buried plastic M14 type mine (5 cm in diameter and 4.2 cm in height) and with the real shape of continuous scatterers (rough surfaces). Moreover a new spatial-based processing method is described for noise reduction and the measurement errors. The processed results show better accuracy and focusing patterns than those previously obtained. This technique neither requires a priori knowledge about the background medium nor needs any pure background measurement.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"64 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":"114878984","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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