The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
K T Wong - One of the best experts on this subject based on the ideXlab platform.
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Vector Cross Product direction finding with an electromagnetic Vector sensor of six orthogonally oriented but spatially noncollocating dipoles loops
IEEE Transactions on Signal Processing, 2011Co-Authors: K T Wong, Xin YuanAbstract:Direction-finding capability has recently been advanced by synergies between the customary approach of inter ferometry and the new approach of “Vector Cross Product” based Poynting-Vector estimator. The latter approach measures the incident electromagnetic wavefield for each of its six electromagnetic components, all at one point in space, to allow a Vector Cross-Product between the measured electric-field Vector and the measured magnetic-field Vector. This would lead to the estimation of each incident source's Poynting-Vector, which (after proper norm-normalization) would then reveal the corresponding Cartesian direction-cosines, and thus the azimuth-elevation arrival angles. Such a “Vector Cross Product” algorithm has been predicated on the measurement of all six electromagnetic components at one same spatial location. This physically requires an electromagnetic Vector-sensor, i.e., three identical but orthogonally oriented electrically short dipoles, plus three identical but orthogonally oriented magnetically small loops-all spatially collocated in a point-like geometry. Such a complicated “Vector-antenna” would require exceptionally effective electromagnetic isolation among its six component-antennas. To minimize mutual coupling aCross these collocated antennas, considerable antennas-complexity and hardware cost could be required. Instead, this paper shows how to apply the “Vector Cross-Product” direction-of-arrival estimator, even if the three dipoles and the three loops are located separately (instead of collocating in a point-like geometry). This new scheme has great practical value, in reducing mutual coupling, in simplifying the antennas hardware, and in sparsely extending the spatial aperture to refine the direction-finding accuracy by orders of magnitude.
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direction finding polarization estimation dipole and or loop triad s
IEEE Transactions on Aerospace and Electronic Systems, 2001Co-Authors: K T WongAbstract:This paper shows (1) how measurement of the three Cartesian components of the electrical-field or magnetic-field suffices for multisource azimuth/elevation direction finding and polarization estimation, and (2) how the Vector Cross-Product direction-of-arrival estimator is fully applicable even when the dipole triad is arbitrarily displaced from the loop triad.
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closed form direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector sensors at unknown locations
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a new closed-form ESPRIT-based algorithm for multisource direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector-sensors whose three-dimensional (3-D) locations need not be known. The Vector-sensor, already commercially available, consists of six colocated but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. ESPRIT exploits the nonspatial interrelations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-field Vector estimate produces an unambiguous estimate of that source's normalized Poynting Vector, which contains as its components the source's Cartesian direction cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme. This novel method maybe considered as a simplification and a refinement over Li's (1993) work.
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closed form direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector sensors at unknown locations
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a new closed-form ESPRIT-based algorithm for multisource direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector-sensors whose three-dimensional (3-D) locations need not be known. The Vector-sensor, already commercially available, consists of six colocated but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. ESPRIT exploits the nonspatial interrelations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-field Vector estimate produces an unambiguous estimate of that source's normalized Poynting Vector, which contains as its components the source's Cartesian direction cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme. This novel method maybe considered as a simplification and a refinement over Li's (1993) work.
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closed form direction finding with arbitrarily spaced electromagnetic Vector sensors at unknown locations
International Conference on Acoustics Speech and Signal Processing, 1998Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a novel closed-form ESPRIT-based algorithm for multi-source direction finding using arbitrarily spaced electromagnetic Vector-sensors whose locations need not be known. The electromagnetic Vector-sensor, already commercially available, consists of six co-located but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. In this novel algorithm, ESPRIT exploits the non-spatial inter-relations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-held Vector estimate: produces an unambiguous estimate of that source's normalized Poynting-Vector, which contains as its components the source's Cartesian direction-cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme.
Xin Yuan - One of the best experts on this subject based on the ideXlab platform.
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a multiscale sparse array of spatially spread electromagnetic Vector sensors for direction finding and polarization estimation
IEEE Access, 2018Co-Authors: Minglei Yang, Jin Ding, Baixiao Chen, Xin YuanAbstract:In this paper, a multiscale sparse array, which is composed of spatially-spread electromagnetic-Vector-sensors (SS-EMVSs), is proposed to estimate the direction-of-arrivals (DOA) and polarizations of multiple sources. The SS-EMVS is composed of three orthogonally oriented but spatially noncollocated dipoles to measure the electric field and three orthogonally oriented but spatially noncollocated loops to measure the magnetic field, simultaneously. In this paper, an array of SS-EMVSs is placed along the $y$ -axis, and this sparse array is composed of two sub-arrays, i.e. , the first $n_{1}$ SS-EMVSs with inter-sensor spacing $D_{1}$ , and the last $n_{2}$ SS-EMVSs with inter-sensor spacing $D_{2}$ , with $D_{2}=mD_{1}$ ; $m>1$ is an integer and $D_{1}$ is larger than a half-wavelength of the incident signal. Thereby, a multiscale sparse array is constructed, which is capable of providing high accuracy estimates of DOA and polarizations of multiple sources. The Vector-Cross-Product algorithm is used to obtain the unambiguous but low-accuracy estimations of direction cosines, and the different inter-sensor spacings are used to estimate high-accuracy but ambiguous estimations of direction cosines. Following this, a multiscale disambiguation algorithm is developed to obtain high-accuracy and unambiguous estimations of direction cosines, thus the elevation angles, azimuth angles, as well as the polarization parameters of multiple sources. Simulation results verify the superior performance of the proposed multiscale SS-EMVS array.
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corrections to Vector Cross Product direction finding with an electromagnetic Vector sensor of six orthogonally oriented but spatially noncollocating dipoles loops jan 11 160 171
IEEE Transactions on Signal Processing, 2014Co-Authors: Yang Song, Xin Yuan, Kainam Thomas WongAbstract:In the above paper (ibid., vol. 59, no. 1, pp. 160-171, Jan. 2011), written by the second and the third authors of this correction, the Monte Carlo simulations are incorrectly conducted in Section V and in Figs. 4-5, for the case of arbitrarily oriented array-axes. This erratum presents a correct algorithm and the correct simulation results, for the case of arbitrarily oriented array-axes. Also presented here will be some other miscellaneous corrections. The second and the third authors apologize for these errors.
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Corrections to “Vector Cross-Product Direction-Finding’ With an Electromagnetic Vector-Sensor of Six Orthogonally Oriented But Spatially Noncollocating Dipoles/Loops” [Jan 11 160-171]
IEEE Transactions on Signal Processing, 2014Co-Authors: Yang Song, Xin Yuan, Kainam Thomas WongAbstract:In the above paper (ibid., vol. 59, no. 1, pp. 160-171, Jan. 2011), written by the second and the third authors of this correction, the Monte Carlo simulations are incorrectly conducted in Section V and in Figs. 4-5, for the case of arbitrarily oriented array-axes. This erratum presents a correct algorithm and the correct simulation results, for the case of arbitrarily oriented array-axes. Also presented here will be some other miscellaneous corrections. The second and the third authors apologize for these errors.
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enhanced Vector Cross Product direction finding using a constrained sparse triangular array
EURASIP Journal on Advances in Signal Processing, 2012Co-Authors: Feng Luo, Xin YuanAbstract:A new configuration of sparse array is proposed in this article to estimate the direction-of-arrivals (DOAs) and polarizations of multiple sources. This constrained sparse array is composed of a dipole-triad, a loop-triad, and a single antenna, which can be a dipole, a loop, or a scalar-sensor. These three units comprise a triangular geometry in the space. This geometry creatively synergizes the conventional interferometry method based on the spatial phase-delay aCross displaced antennas, and the "Vector-Cross-Product" based on Poynting-Vector estimator to enhance the DOA estimation accuracy. The investigated algorithm based on this configuration adopts the "Vector-Cross-Product" DOA estimator to provide the coarse estimate and then derives the fine estimate by extracting the inter-sensor phase factors in the sparse array. Following this, the disambiguation approach is adapted to derive the unambiguous estimate, and this estimate is also fine in estimation resolution. The proposed configuration can extend the array aperture and also reduce the mutual coupling. The significant performance of the proposed sparse array composition is demonstrated by Monte Carlo simulations when the inter-sensor spacing far exceeds a half-wavelength.
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Vector Cross Product direction finding with an electromagnetic Vector sensor of six orthogonally oriented but spatially noncollocating dipoles loops
IEEE Transactions on Signal Processing, 2011Co-Authors: K T Wong, Xin YuanAbstract:Direction-finding capability has recently been advanced by synergies between the customary approach of inter ferometry and the new approach of “Vector Cross Product” based Poynting-Vector estimator. The latter approach measures the incident electromagnetic wavefield for each of its six electromagnetic components, all at one point in space, to allow a Vector Cross-Product between the measured electric-field Vector and the measured magnetic-field Vector. This would lead to the estimation of each incident source's Poynting-Vector, which (after proper norm-normalization) would then reveal the corresponding Cartesian direction-cosines, and thus the azimuth-elevation arrival angles. Such a “Vector Cross Product” algorithm has been predicated on the measurement of all six electromagnetic components at one same spatial location. This physically requires an electromagnetic Vector-sensor, i.e., three identical but orthogonally oriented electrically short dipoles, plus three identical but orthogonally oriented magnetically small loops-all spatially collocated in a point-like geometry. Such a complicated “Vector-antenna” would require exceptionally effective electromagnetic isolation among its six component-antennas. To minimize mutual coupling aCross these collocated antennas, considerable antennas-complexity and hardware cost could be required. Instead, this paper shows how to apply the “Vector Cross-Product” direction-of-arrival estimator, even if the three dipoles and the three loops are located separately (instead of collocating in a point-like geometry). This new scheme has great practical value, in reducing mutual coupling, in simplifying the antennas hardware, and in sparsely extending the spatial aperture to refine the direction-finding accuracy by orders of magnitude.
M D Zoltowski - One of the best experts on this subject based on the ideXlab platform.
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closed form direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector sensors at unknown locations
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a new closed-form ESPRIT-based algorithm for multisource direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector-sensors whose three-dimensional (3-D) locations need not be known. The Vector-sensor, already commercially available, consists of six colocated but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. ESPRIT exploits the nonspatial interrelations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-field Vector estimate produces an unambiguous estimate of that source's normalized Poynting Vector, which contains as its components the source's Cartesian direction cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme. This novel method maybe considered as a simplification and a refinement over Li's (1993) work.
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closed form direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector sensors at unknown locations
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a new closed-form ESPRIT-based algorithm for multisource direction finding and polarization estimation with arbitrarily spaced electromagnetic Vector-sensors whose three-dimensional (3-D) locations need not be known. The Vector-sensor, already commercially available, consists of six colocated but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. ESPRIT exploits the nonspatial interrelations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-field Vector estimate produces an unambiguous estimate of that source's normalized Poynting Vector, which contains as its components the source's Cartesian direction cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme. This novel method maybe considered as a simplification and a refinement over Li's (1993) work.
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closed form direction finding with arbitrarily spaced electromagnetic Vector sensors at unknown locations
International Conference on Acoustics Speech and Signal Processing, 1998Co-Authors: K T Wong, M D ZoltowskiAbstract:This paper introduces a novel closed-form ESPRIT-based algorithm for multi-source direction finding using arbitrarily spaced electromagnetic Vector-sensors whose locations need not be known. The electromagnetic Vector-sensor, already commercially available, consists of six co-located but diversely polarized antennas separately measuring all six electromagnetic-field components of an incident wavefield. In this novel algorithm, ESPRIT exploits the non-spatial inter-relations among the six unknown electromagnetic-field components of each source and produces from the measured data a set of eigenvalues, from which the source's electromagnetic-field Vector may be estimated to within a complex scalar. Application of a Vector Cross-Product operation to this ambiguous electromagnetic-held Vector estimate: produces an unambiguous estimate of that source's normalized Poynting-Vector, which contains as its components the source's Cartesian direction-cosines. Monte Carlo simulation results verify the efficacy and versatility of this innovative scheme.
David Brie - One of the best experts on this subject based on the ideXlab platform.
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A generalized acquisition scheme for Vector Cross-Product direction finding with spatially spread Vector-sensor component
2013Co-Authors: Yazid Merah, Sebastian Miron, David BrieAbstract:In this paper we propose a generalized non-collocated electromagnetic (EM) Vector-sensor configuration allowing the use of the Vector Cross-Product direction finding scheme. We provide a sufficient condition ensuring identifiability of source DOA parameters and propose a novel algorithm allowing the DOA estimation for inter-antenna spacing larger than lambda/2. The effectiveness of the proposed approach is illustrated by numerical simulations.
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a generalized acquisition scheme for Vector Cross Product direction findingwith spatially spread Vector sensor components
International Conference on Acoustics Speech and Signal Processing, 2013Co-Authors: Yazid Merah, Sebastian Miron, David BrieAbstract:In this paper we propose a generalized non-collocated electromagnetic (EM) Vector-sensor configuration allowing the use of the Vector Cross-Product direction finding scheme. The presented work extends the results and the philosophy of [1] to a more general array configuration. We provide a sufficient condition ensuring identifiability of source DOA parameters and propose a novel algorithm allowing the DOA estimation for inter-antenna spacing larger than λ/2. The effectiveness of the proposed approach is illustrated by numerical simulations.
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ICASSP - A generalized acquisition scheme for Vector Cross-Product direction findingwith spatially spread Vector-sensor components
2013 IEEE International Conference on Acoustics Speech and Signal Processing, 2013Co-Authors: Yazid Merah, Sebastian Miron, David BrieAbstract:In this paper we propose a generalized non-collocated electromagnetic (EM) Vector-sensor configuration allowing the use of the Vector Cross-Product direction finding scheme. The presented work extends the results and the philosophy of [1] to a more general array configuration. We provide a sufficient condition ensuring identifiability of source DOA parameters and propose a novel algorithm allowing the DOA estimation for inter-antenna spacing larger than λ/2. The effectiveness of the proposed approach is illustrated by numerical simulations.
Kainam Thomas Wong - One of the best experts on this subject based on the ideXlab platform.
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A Six-Component Vector Sensor Comprising Electrically Long Dipoles and Large Loops— To Simultaneously Estimate Incident Sources’ Directions-of-Arrival and Polarizations
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Salman Khan, Kainam Thomas WongAbstract:An “electromagnetic Vector sensor” (EMVS) comprises three orthogonal dipoles and three orthogonal loops, all in spatial collocation. The former triplet aims to directly measure the $3 \times 1$ electric-field Vector ${\mathbf{e}} $ , whereas the latter triplet aims to directly measure the $3 \times 1$ magnetic-field Vector ${\mathbf{h}} $ . Their Vector Cross Product $ {\mathbf{e}} \times {\mathbf{h}} $ would yield the incident source’s Poynting Vector, which specifies the incident wavefield’s propagation direction. In reality, all these are only an idealization. Instead, a real-world dipole triad’s measurement could equal the incident ${\mathbf{e}} $ , only if the dipoles were electrically short (i.e., with an electrical length of $({L}/{\lambda }) ). Likewise, a practical loop triad’s measurement could equal the incident ${\mathbf{h}} $ , only if the loops were electrically small (i.e., with an electrical circumference of $2 \pi ({R}/{\lambda }) ). However, such short dipoles and small loops would be electromagnetically inefficient receivers. For a practical dipole that is electrically long , its measurement equals not the incident wavefield’s ${\mathbf{e}} $ but a Vector dot Product between: 1) the incident wave’s ${\mathbf{e}}$ and 2) that dipole antenna’s “effective length” Vector (which depends on that dipole’s $({L}/{\lambda })$ and orientation). An analogous complexity exists for a practical loop that is electrically large . For such practical dipoles and loops, the aforementioned Vector-Cross-Product would fail to yield the Poynting Vector, hence it would inaccurately estimate the direction-of-arrival. Instead, this article will advance a new closed-form algorithm to simultaneously estimate an incident source’s direction-of-arrival and polarization, despite the practical dipoles’/ loops’ mathematically complicated gain/phase responses as described earlier, but without any prior knowledge of the dipoles’ electric length $({L}/{\lambda })$ nor the loops’ electric radius $({R}/{\lambda })$ .
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corrections to Vector Cross Product direction finding with an electromagnetic Vector sensor of six orthogonally oriented but spatially noncollocating dipoles loops jan 11 160 171
IEEE Transactions on Signal Processing, 2014Co-Authors: Yang Song, Xin Yuan, Kainam Thomas WongAbstract:In the above paper (ibid., vol. 59, no. 1, pp. 160-171, Jan. 2011), written by the second and the third authors of this correction, the Monte Carlo simulations are incorrectly conducted in Section V and in Figs. 4-5, for the case of arbitrarily oriented array-axes. This erratum presents a correct algorithm and the correct simulation results, for the case of arbitrarily oriented array-axes. Also presented here will be some other miscellaneous corrections. The second and the third authors apologize for these errors.
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Corrections to “Vector Cross-Product Direction-Finding’ With an Electromagnetic Vector-Sensor of Six Orthogonally Oriented But Spatially Noncollocating Dipoles/Loops” [Jan 11 160-171]
IEEE Transactions on Signal Processing, 2014Co-Authors: Yang Song, Xin Yuan, Kainam Thomas WongAbstract:In the above paper (ibid., vol. 59, no. 1, pp. 160-171, Jan. 2011), written by the second and the third authors of this correction, the Monte Carlo simulations are incorrectly conducted in Section V and in Figs. 4-5, for the case of arbitrarily oriented array-axes. This erratum presents a correct algorithm and the correct simulation results, for the case of arbitrarily oriented array-axes. Also presented here will be some other miscellaneous corrections. The second and the third authors apologize for these errors.
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Direction finding/polarization estimation-dipole and/or loop triad(s)
IEEE Transactions on Aerospace and Electronic Systems, 2001Co-Authors: Kainam Thomas WongAbstract:This paper shows (1) how measurement of the three Cartesian components of the electrical-field or magnetic-field suffices for multisource azimuth/elevation direction finding and polarization estimation, and (2) how the Vector Cross-Product direction-of-arrival estimator is fully applicable even when the dipole triad is arbitrarily displaced from the loop triad.