The Experts below are selected from a list of 9252 Experts worldwide ranked by ideXlab platform
Waymond R Scott - One of the best experts on this subject based on the ideXlab platform.
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ultrasonic displacement sensor for the seismic detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: James S Martin, Douglas Fenneman, Waymond R Scott, G D Larson, Fabien T Codron, Peter H Rogers, George S MccallAbstract:A system is under development that uses seismic surface waves to detect and image buried LandMines. The system, which has been previously reported in the literature, requires a sensor that does not contact the soil surface. Thus, the seismic signal can be evaluated directly above a candidate mine location. The system can then utilize small amplitude and non-propagating components of the seismic wave field to form an image. Currently, a radar-based sensor is being used in this system. A less expensive alternative to this is an ultrasonic sensor that works on similar principles to the radar but exploits a much slower acoustic wave speed to achieve comparable performance at an operating frequency 5 to 6 decades below the radar frequency. The prototype ultrasonic sensor interrogates the soil with a 50 kHz acoustic signal. This signal is reflected from the soil surface and phase modulated by the surface motion. The displacement can be extracted from this modulation using either analog or digital electronics. The analog scheme appears to offer both the lowest cost and the best performance in initial testing. The sensor has been tested using damp compacted sand as a soil surrogate and has demonstrated a spatial resolution and signal-to-noise ratio comparable to those that have been achieved with the radar sensor. In addition to being low-cost, the ultrasonic sensor also offers the potential advantage of penetrating different forms of ground cover than those that are permeable to the radar signal. This is because density and stiffness contrasts mediate ultrasonic reflections whereas electromagnetic reflection is governed by dielectric contrast.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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technical issues associated with the detection of buried Land Mines with high frequency seismic waves
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: Seungho Lee, Waymond R Scott, James S Martin, G D Larson, George S MccallAbstract:An array of radars is developed as a stand off sensor for use in elastic/seismic mine detection systems. The array consists of N radar sensors which operate independently to sense the displacement of the surface of the earth due to elastic waves propagating in the earth. Each of the sensors consists of a lens-focused, conical, corrugated, horn antenna and a homodyne radar. The focused antenna allows the sensor to have greater standoff than with the previous unfocused antenna while maintaining the spatial resolution required for a mine detection system. By using an array of N sensors instead of a single sensor, the scan rate of the array is improved by a factor of N. A theoretical model for the focused antenna is developed and an array of two radars is developed and used to validate the theoretical model. This array is tested in both the experimental and the field models for the elastic mine detection system. Results from both systems are presented.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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elastic waves interacting with buried Land Mines a study using the fdtd method
IEEE Transactions on Geoscience and Remote Sensing, 2002Co-Authors: C T Schroder, Waymond R Scott, G D LarsonAbstract:A three-dimensional (3-D) finite-difference model for elastic waves in the ground has been developed and implemented. The model has been created to supplement the development of a sensor that uses elastic waves to detect buried Land Mines. The model is used to investigate the propagation characteristics of elastic waves in the ground and to explore the interaction of elastic waves with buried Land Mines. When elastic waves interact with a buried mine, a strong resonance occurs at the mine location. The resonance can be used to enhance the mine's signature and to distinguish the mine from clutter. Results presented in this paper explain the features of elastic wave propagation in the ground and show the interaction of elastic waves with both an anti-personnel mine and an anti-tank mine.
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simultaneous use of elastic and electromagnetic waves for the detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2000Co-Authors: Waymond R Scott, G D Larson, James S MartinAbstract:A hybrid technique has been developed that uses both electromagnetic and elastic waves in a synergistic manner to detect buried Land Mines. The system consists of a moving electromagnetic radar and a stationary elastic-wave source. The source generates elastic waves in the earth. These waves interact with the buried mine and cause both the mine and the earth to be displaced. Because the mechanical properties of the mine are different from those of the earth, the displacements in the region of interaction are distinct from those associated with the free-field propagation of the waves. The radar is used to detect displacement and, thus, the mine. Initial investigations have demonstrated the feasibility of this scheme under controlled conditions. The current experimental effort if focused on understanding and overcoming the issues associated with using the system in field conditions.
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a finite difference model to study the elastic wave interactions with buried Land Mines
IEEE Transactions on Geoscience and Remote Sensing, 2000Co-Authors: C T Schroder, Waymond R ScottAbstract:A two-dimensional (2-D) finite-difference model for elastic waves in the ground has been developed. The model uses the equation of motion and the stress-strain relation, from which a first-order stress-velocity formulation is obtained. The resulting system of equations is discretized using centered finite-differences. A perfectly matched layer surrounds the discretized solution space and absorbs the outward traveling waves. The numerical model is validated by comparison to an analytical solution. The numerical model is used to study the interaction of elastic waves with a buried Land mine. It is seen that the presence of an air-chamber within the mine gives rise to resonant oscillations that are clearly visible on the surface above the mine. The resonance is shown to be due to flexural waves being trapped within the thin layer between the surface of the ground and the air chamber of the mine. The numerical results are in good qualitative agreement with experimental observations.
Melvin Felton - One of the best experts on this subject based on the ideXlab platform.
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remote detection of buried Land Mines and ieds using lwir polarimetric imaging
Optics Express, 2012Co-Authors: Kristan P Gurton, Melvin FeltonAbstract:We report results of an ongoing study designed to assess the ability for enhanced detection of recently buried Land-Mines and/or improvised explosive devices (IED) devices using passive long-wave infrared (LWIR) polarimetric imaging. Polarimetric results are presented for a series of field tests conducted at various locations and soil types. Well-calibrated Stokes images, S0, S1, S2, and the degree-of-linear-polarization (DoLP) are recorded for different line-of-sight (LOS) slant paths at varying distances. Results span a three-year time period in which three different LWIR polarimetric camera systems are used. All three polarimetric imaging platforms used a spinning-achromatic-retarder (SAR) design capable of achieving high polarimetric frame rates and good radiometric throughput without the loss of spatial resolution inherent in other optical designs. Receiver-operating-characteristic (ROC) analysis and a standardized contrast parameter are used to compare detectability between conventional LWIR thermal and polarimetric imagery. Results suggest improved detectability, regardless of geographic location or soil type.
Paul D Gader - One of the best experts on this subject based on the ideXlab platform.
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detection and discrimination of Land Mines based on edge histogram descriptors and fuzzy k nearest neighbors
IEEE International Conference on Fuzzy Systems, 2006Co-Authors: Hichem Frigui, Paul D GaderAbstract:This paper describes an algorithm for Land mine detection using sensor data generated by a ground penetrating radar (GPR) system. The GPR produces a 3-D array of intensity values, representing a volume below the surface of the ground. First, a computationally inexpensive pre-screening algorithm is used to focus attention and identify regions with subsurface anomalies. The identified regions of interest are then processed by a feature extraction algorithm to capture their salient features. We use translation invariant features that are based on the local edge distribution of the 3-D GPR signatures. Finally, a fuzzy K-nearest neighbor rule is used to assign a confidence value to distinguish true detections from false alarms. The proposed algorithm is applied to data acquired from three outdoor test sites at different geographic locations.
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detection of Land Mines using fuzzy and possibilistic membership functions
IEEE International Conference on Fuzzy Systems, 2003Co-Authors: Hichem Frigui, K Satyanarayana, Paul D GaderAbstract:This paper introduces a new system for real-time Land mine detection using sensor data generated by a Ground Penetrating Radar (GPR). The GPR produces a three-dimensional array of intensity values, representing a volume below the surface of the ground. Features are computed from this array and two types of membership degrees are assigned to each location. A fuzzy membership value provides a degree of belongingness of a given observation in the classes of Mines, false alarms, and background, while a possibilistic membership value provides a degree of typicality. Both membership degrees are combined using simple rules to assign a confidence value. The parameters of the membership functions are obtained by clustering the training data and using the statistics of each partition. Our preliminary results show that the proposed approach is simple, efficient, and yet, yields results comparable to more complex detection systems.
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recognition technology for the detection of buried Land Mines
IEEE Transactions on Fuzzy Systems, 2001Co-Authors: Paul D Gader, James M Keller, Bruce N NelsonAbstract:As described by Zadeh, recognition technology refers to systems that incorporate new sensors, novel signal processing, and soft computing. In this paper, we discuss these principles applied to the problem of Land mine detection. We describe a complex recognition system that is evolving from basic research into a fielded system. Some components of this system have been field tested with excellent results, whereas other components have achieved such results in the laboratory. Fuzzy set-based information fusion algorithms are central to the excellent results obtained. Multiple-detection algorithms are applied to signals acquired from an innovative ground penetrating radar that produces volumetric sub-surface imagery. The outputs of the detection algorithms are combined using the fuzzy logic and Sugeno and Choquet fuzzy integrals to produce overall detection scores. Experimental results are provided on training data and on completely blind test data collected in the field and scored by the US Army.
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applications of hidden markov models to detecting Land Mines with ground penetrating radar
International Conference on Multimedia Information Networking and Security, 1999Co-Authors: Paul D Gader, Miroslaw MystkowskiAbstract:Algorithms for detecting Land Mines using the GEO-CENTERS, Vehicle-Based Energy Focusing Ground Penetrating Radar (EFGPR) are presented. The algorithms rely on the use of hidden Markov models to model the time-varying signatures produces by the interaction of the EFGPR and the LandMines as the vehicle moves. Results are presented on isolated Land mine signatures isolated from calibration lane data from Fort A.P. Hill in the summer of 1998.
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new results in fuzzy set based detection of Land Mines with gpr
International Conference on Multimedia Information Networking and Security, 1999Co-Authors: Paul D Gader, Hichem Frigui, Bruce N Nelson, Gary Vaillette, James M KellerAbstract:Algorithms for detecting Land Mines using the GEO-CENTERS Energy Focusing Ground Penetrating Radar (EFGPR) are presented. Key elements of the system include normalization, down- and cross-track feature extraction, fuzzy set membership based confidence assignment, and false alarm testing via transition and number of hyperbolae features. The system has been implemented in real-time in the GEO- CENTERS Vehicle Mounted Mine Detection System and can be used to perform real-time Land mine detection or to analyze data stored to disk. Results are presented on calibration lane data from Aberdeen Proving Grounds, MaryLand and the Energetic Materials Research and Testing Center, New Mexico in the summer of 1998.
James S Martin - One of the best experts on this subject based on the ideXlab platform.
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technical issues associated with the detection of buried Land Mines with high frequency seismic waves
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: Seungho Lee, Waymond R Scott, James S Martin, G D Larson, George S MccallAbstract:An array of radars is developed as a stand off sensor for use in elastic/seismic mine detection systems. The array consists of N radar sensors which operate independently to sense the displacement of the surface of the earth due to elastic waves propagating in the earth. Each of the sensors consists of a lens-focused, conical, corrugated, horn antenna and a homodyne radar. The focused antenna allows the sensor to have greater standoff than with the previous unfocused antenna while maintaining the spatial resolution required for a mine detection system. By using an array of N sensors instead of a single sensor, the scan rate of the array is improved by a factor of N. A theoretical model for the focused antenna is developed and an array of two radars is developed and used to validate the theoretical model. This array is tested in both the experimental and the field models for the elastic mine detection system. Results from both systems are presented.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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ultrasonic displacement sensor for the seismic detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: James S Martin, Douglas Fenneman, Waymond R Scott, G D Larson, Fabien T Codron, Peter H Rogers, George S MccallAbstract:A system is under development that uses seismic surface waves to detect and image buried LandMines. The system, which has been previously reported in the literature, requires a sensor that does not contact the soil surface. Thus, the seismic signal can be evaluated directly above a candidate mine location. The system can then utilize small amplitude and non-propagating components of the seismic wave field to form an image. Currently, a radar-based sensor is being used in this system. A less expensive alternative to this is an ultrasonic sensor that works on similar principles to the radar but exploits a much slower acoustic wave speed to achieve comparable performance at an operating frequency 5 to 6 decades below the radar frequency. The prototype ultrasonic sensor interrogates the soil with a 50 kHz acoustic signal. This signal is reflected from the soil surface and phase modulated by the surface motion. The displacement can be extracted from this modulation using either analog or digital electronics. The analog scheme appears to offer both the lowest cost and the best performance in initial testing. The sensor has been tested using damp compacted sand as a soil surrogate and has demonstrated a spatial resolution and signal-to-noise ratio comparable to those that have been achieved with the radar sensor. In addition to being low-cost, the ultrasonic sensor also offers the potential advantage of penetrating different forms of ground cover than those that are permeable to the radar signal. This is because density and stiffness contrasts mediate ultrasonic reflections whereas electromagnetic reflection is governed by dielectric contrast.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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simultaneous use of elastic and electromagnetic waves for the detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2000Co-Authors: Waymond R Scott, G D Larson, James S MartinAbstract:A hybrid technique has been developed that uses both electromagnetic and elastic waves in a synergistic manner to detect buried Land Mines. The system consists of a moving electromagnetic radar and a stationary elastic-wave source. The source generates elastic waves in the earth. These waves interact with the buried mine and cause both the mine and the earth to be displaced. Because the mechanical properties of the mine are different from those of the earth, the displacements in the region of interaction are distinct from those associated with the free-field propagation of the waves. The radar is used to detect displacement and, thus, the mine. Initial investigations have demonstrated the feasibility of this scheme under controlled conditions. The current experimental effort if focused on understanding and overcoming the issues associated with using the system in field conditions.
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experimental investigation of the acousto electromagnetic sensor for locating Land Mines
International Conference on Multimedia Information Networking and Security, 1999Co-Authors: Waymond R Scott, James S MartinAbstract:A hybrid technique is presented that simultaneously uses both electromagnetic and acoustic waves in a synergistic manner to detect buried Land Mines. The system consists of an electromagnetic radar and an acoustic source. The acoustic source causes both the mine and the surface of the earth to be displaced. The electromagnetic radar is used to detect these displacements and, thus, the mine. To demonstrate the viability of this technique, experimental models have been constructed. The models use an electrodynamic transducer to generate an acoustic surface wave, a tank filled with damp sand to simulate the earth, simulated Mines, and a radar to measure the vibrations. The technique looks promising; we have been able to measure the interactions of the acoustic waves with both simulated antipersonnel Mines and antitank miens buried in damp sand. We have measured strong resonance in some of the Mines; these resonances are shown to help differentiate the mine from clutter.
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acousto electromagnetic sensor for locating Land Mines
International Conference on Multimedia Information Networking and Security, 1998Co-Authors: Waymond R Scott, Christoph T Schroeder, James S MartinAbstract:A hybrid technique is presented that simultaneously uses both electromagnetic and acoustic waves in a synergistic manner to detect buried Land Mines. The system consists of an electromagnetic radar and an acoustic source. The acoustic source causes both the mine and the surface of the earth to be displaced. The electromagnetic radar is used to detect these displacements and, thus, the mine. To demonstrate the viability of this technique, an experimental system has been constructed. The system uses an electrodynamic transducer to induce an acoustic surface wave, a tank filled with damp sand to simulate the earth, a simulated mine, and a radar to measure the vibrations. The technique looks promising; we have been able to detect both simulated antipersonnel Mines and antitank Mines buried in damp sand from the experimental results obtained with the system.
G D Larson - One of the best experts on this subject based on the ideXlab platform.
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ultrasonic displacement sensor for the seismic detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: James S Martin, Douglas Fenneman, Waymond R Scott, G D Larson, Fabien T Codron, Peter H Rogers, George S MccallAbstract:A system is under development that uses seismic surface waves to detect and image buried LandMines. The system, which has been previously reported in the literature, requires a sensor that does not contact the soil surface. Thus, the seismic signal can be evaluated directly above a candidate mine location. The system can then utilize small amplitude and non-propagating components of the seismic wave field to form an image. Currently, a radar-based sensor is being used in this system. A less expensive alternative to this is an ultrasonic sensor that works on similar principles to the radar but exploits a much slower acoustic wave speed to achieve comparable performance at an operating frequency 5 to 6 decades below the radar frequency. The prototype ultrasonic sensor interrogates the soil with a 50 kHz acoustic signal. This signal is reflected from the soil surface and phase modulated by the surface motion. The displacement can be extracted from this modulation using either analog or digital electronics. The analog scheme appears to offer both the lowest cost and the best performance in initial testing. The sensor has been tested using damp compacted sand as a soil surrogate and has demonstrated a spatial resolution and signal-to-noise ratio comparable to those that have been achieved with the radar sensor. In addition to being low-cost, the ultrasonic sensor also offers the potential advantage of penetrating different forms of ground cover than those that are permeable to the radar signal. This is because density and stiffness contrasts mediate ultrasonic reflections whereas electromagnetic reflection is governed by dielectric contrast.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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technical issues associated with the detection of buried Land Mines with high frequency seismic waves
International Conference on Multimedia Information Networking and Security, 2002Co-Authors: Seungho Lee, Waymond R Scott, James S Martin, G D Larson, George S MccallAbstract:An array of radars is developed as a stand off sensor for use in elastic/seismic mine detection systems. The array consists of N radar sensors which operate independently to sense the displacement of the surface of the earth due to elastic waves propagating in the earth. Each of the sensors consists of a lens-focused, conical, corrugated, horn antenna and a homodyne radar. The focused antenna allows the sensor to have greater standoff than with the previous unfocused antenna while maintaining the spatial resolution required for a mine detection system. By using an array of N sensors instead of a single sensor, the scan rate of the array is improved by a factor of N. A theoretical model for the focused antenna is developed and an array of two radars is developed and used to validate the theoretical model. This array is tested in both the experimental and the field models for the elastic mine detection system. Results from both systems are presented.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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elastic waves interacting with buried Land Mines a study using the fdtd method
IEEE Transactions on Geoscience and Remote Sensing, 2002Co-Authors: C T Schroder, Waymond R Scott, G D LarsonAbstract:A three-dimensional (3-D) finite-difference model for elastic waves in the ground has been developed and implemented. The model has been created to supplement the development of a sensor that uses elastic waves to detect buried Land Mines. The model is used to investigate the propagation characteristics of elastic waves in the ground and to explore the interaction of elastic waves with buried Land Mines. When elastic waves interact with a buried mine, a strong resonance occurs at the mine location. The resonance can be used to enhance the mine's signature and to distinguish the mine from clutter. Results presented in this paper explain the features of elastic wave propagation in the ground and show the interaction of elastic waves with both an anti-personnel mine and an anti-tank mine.
-
simultaneous use of elastic and electromagnetic waves for the detection of buried Land Mines
International Conference on Multimedia Information Networking and Security, 2000Co-Authors: Waymond R Scott, G D Larson, James S MartinAbstract:A hybrid technique has been developed that uses both electromagnetic and elastic waves in a synergistic manner to detect buried Land Mines. The system consists of a moving electromagnetic radar and a stationary elastic-wave source. The source generates elastic waves in the earth. These waves interact with the buried mine and cause both the mine and the earth to be displaced. Because the mechanical properties of the mine are different from those of the earth, the displacements in the region of interaction are distinct from those associated with the free-field propagation of the waves. The radar is used to detect displacement and, thus, the mine. Initial investigations have demonstrated the feasibility of this scheme under controlled conditions. The current experimental effort if focused on understanding and overcoming the issues associated with using the system in field conditions.
