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Grzegorczyk T.M.,Delpsi LLC | Barrowes B.,United States ERDC Cold Regions Research and Engineering Laboratory | George D.,G and G science Inc | Shubitidze F.,Dartmouth College | O'Neill K.,United States ERDC Cold Regions Research and Engineering Laboratory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Dynamic data from the MetalMapper electromagnetic induction sensor are analyzed using a fast inversion algorithm in order to obtain position information of buried anomalies. After validating the algorithm by comparing static and dynamic inversions from reference measurements at Camp San Luis Obispo, the algorithm is applied to realistic dynamic measurements from Camp Butner. A sequence of 939 data points are inverted as the MetalMapper travels along a calibration lane, flagging a few positions as corresponding to buried anomalies. An a posteriori comparison with field plots reveals a good agreement between the flagged positions and the field peak values, suggesting the efficacy of the algorithm at detecting a large variety of anomalies from dynamic data. © 2011 SPIE. Source


Shubitidze F.,Dartmouth College | Barrowes B.,United States ERDC Cold Regions Research and Engineering Laboratory | Shamatava I.,Sky Research, Inc. | Fernandez J.P.,Dartmouth College | O'Neill K.,United States ERDC Cold Regions Research and Engineering Laboratory
SEG Technical Program Expanded Abstracts | Year: 2011

The orttho-normalized volume magnetic source technique (ONMVS) [1] is applied to Camp Butner, NC, live-site UXO MetalMapper data inversion and subsurface metallic target discrimination. The ONVMS model can be considered as a generalized surface dipole model, and in fact reverts to the point dipole model as a limiting case. The method is based on the assumption that a collection of scatterers can be replaced with a set of magnetic dipole sources, distributed over a volume. These sources mimic the eddy currents and thereby the magnetic response that are induced on the targets by the primary magnetic field, and that in turn establish the observable secondary field. In this study, twenty-four hundred anomalies were processed. The anomaly sets included three types of UXOs: M48 Fuze, 105 mm and 37 mm projectiles. The effective total ONVMS amplitudes were used to discriminate UXO's from metallic clutter. The amplitudes of the total ONVMS were determined for each anomaly along three orthogonal axes by inverting MetalMapper data using the combined ONVMS and differential evolution algorithm. The inverted anomalies were ranked as UXO and non-UXO targets and submitted to the Institute for Defense Analyses (IDA) for independent scoring. The independent scoring results that are presented here, suggest that the ONVMS technique has the potential to improve UXO classification. © 2011 Society of Exploration Geophysicists. Source


Grzegorczyk T.M.,Delpsi LLC | Barrowes B.,United States ERDC Cold Regions Research and Engineering Laboratory | Shubitidze F.,Dartmouth College | Shubitidze F.,Sky Research, Inc. | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The detection of unexploded ordnance (UXO) in the electromagnetic induction regime often suffers from a low signal to noise ratio due to the strong decay of the magnetic field. As a result, a deep UXO may be overshadowed by smaller yet shallower metal items which render the classification of the main target challenging. It is therefore desirable to have the ability to model the various sources of noise and to include them in a detection algorithm. Toward this effect, we investigate here Kalman and extended Kalman filters for the inversion of UXO polarizabilities and positions, respectively, within a dipole model approximation. Inherent to the method, our analysis is based on the assumption of Gaussian noise distribution, which is often reasonable. Results are shown on both synthetic and TEMTADS data which have been purposely corrupted with noise. In particular, the situation of a main target in the presence of dense clutter is investigated, whereby the clutter is composed of 16 nosepieces buried close to the sensor. © 2010 Copyright SPIE - The International Society for Optical Engineering. Source


Shamatava I.,Sky Research, Inc. | Shamatava I.,Dartmouth College | Shamatava I.,Delpsi LLC | Shubitidze F.,Sky Research, Inc. | And 8 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Discrimination studies carried out on TEMTADS and Metal Mapper blind data sets collected at the San Luis Obispo UXO site are presented. The data sets included four types of targets of interest: 2.36'' rockets, 60-mm mortar shells, 81-mm projectiles, and 4.2'' mortar items. The total parameterized normalized magnetic source (NSMS) amplitudes were used to discriminate TOI from metallic clutter and among the different hazardous UXO. First, in object's frame coordinate, the total NSMS were determined for each TOI along three orthogonal axes from the training data provided by the Strategic Environmental Research and Development Program (SERDP) along with the referred blind data sets. Then the inverted total NSMS were used to extract the time-decay classification features. Once our inversion and classification algorithms were tested on the calibration data sets then we applied the same procedure to all blind data sets. The combined NSMS and differential evolution algorithm is utilized for determine the NSMS strengths for each cell. The obtained total NSMS time-decay curves were used to extract the discrimination features and perform classification using the training data as reference. In addition, for cross validation, the inverted locations and orientations from NSMS-DE algorithm were compared against the inverted data that obtained via the magnetic field, vector and scalar potentials (HAP) method and the combined dipole and Gauss-Newton approach technique. We examined the entire time decay history of the total NSMS case-by-case for classification purposes. Also, we use different multi-class statistical classification algorithms for separating the dangerous objects from non hazardous items. The inverted targets were ranked by target ID and submitted to SERDP for independent scoring. The independent scoring results are presented. © 2010 Copyright SPIE - The International Society for Optical Engineering. Source


Shubitidze F.,Dartmouth College | Shubitidze F.,Sky Research, Inc. | Shamatava I.,Dartmouth College | Shamatava I.,Sky Research, Inc. | And 6 more authors.
Proceedings of International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, DIPED | Year: 2012

The ortho-normalized volume magnetic source (ONVMS) technique is applied to a new time domain EMI instrument called portable decoupled electromagnetic induction sensor (PEDEMIS); The system provides multiple deployment options (carted or carried); multimode operation (detection, interrogation, deep detection, wide interrogation); multi static data that is collected with flexible, decoupled and detachable sensors with precise positioning. In this paper we first describe the geometries of the PEDEMIS transmitters and receivers, then present the procedures to model the way they establish primary fields and measure subsurface responses, and, finally, illustrate the comparisons between modeled and actual data. © 2012 Pidstryhach Institute of Applied Problem. Source

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