The multi-valued Bartlett (MVB) processor is useful for determining the locations of multiple acoustic sources in the ocean [J. Acoust. Soc. Am. 97, 235-241 (1995)]. This approach was originally applied to a vertical ...
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The multi-valued Bartlett (MVB) processor is useful for determining the locations of multiple acoustic sources in the ocean [J. Acoust. Soc. Am. 97, 235-241 (1995)]. This approach was originally applied to a vertical line array of hydrophones. The application to a rectangular array is explored here. The MVB processor is an eigen-processor that is based on the eigenvectors of the covariance matrix. It is multi-valued in the sense that an ambiguity surface is constructed for each member of a subset of the eigenvectors that correspond to the largest eigenvalues. The motivation for the approach is the fact that energy from different sources tends to partition into different eigenvectors. One of the advantages of the MVB processor on a rectangular array is that it is possible to determine if the partitioning is favorable without computing replica fields, which is often the most time-consuming task of matched-field processing computations. Examples are presented to illustrate the capabilities and limitations of the approach.
In order to efficiently estimate the angle of arrival (AOA) information from the closely located signal sources, in this paper, we introduce a cascade AOA estimation technique based on the CAPON and beamspace Multiple...
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ISBN:
(纸本)9788957083048
In order to efficiently estimate the angle of arrival (AOA) information from the closely located signal sources, in this paper, we introduce a cascade AOA estimation technique based on the CAPON and beamspace Multiple Signal Classification (MUSIC) algorithms. First, the cascade approach estimates AOA groups consisting of multiple AOAs using CAPON, and then estimates the individual AOA in the AOA group using beamspace MUSIC. In this paper, we employ the rectangular array anttena for the cascade algorithm.
In three-dimensional (3D) medical ultrasound imaging with two-dimensional (2D) arrays, sparse 2D arrays have been studied to reduce the number of active channels. Among them, sparse 2D arrays with regular or uniform a...
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In three-dimensional (3D) medical ultrasound imaging with two-dimensional (2D) arrays, sparse 2D arrays have been studied to reduce the number of active channels. Among them, sparse 2D arrays with regular or uniform arrangements of elements have advantages of low side lobe energy and uniform field responses over the entire field of view. This paper presents two uniform sparse array models: sparse rectangular arrays (SRAs) on a rectangular grid and sparse spiral arrays (SSAs) on a sunflower grid. Both arrays can be easily implemented on the commercially available or the custom-made arrays. To suppress the overall grating lobe levels, the transmit (Tx) and receive (Rx) array pairs of both the array models are designed not to have grating lobes at the same locations in the Tx/Rx beam patterns, for which the theoretical design rules are also proposed. Computer simulation results indicate that the proposed array pairs for both the SRAs and the SSAs achieve peak grating lobe levels below -40 dB using about a quarter of the number of elements in the dense rectangular array while maintaining similar beam widths to that of the dense array pair.
This paper describes the performance of robust rectangular antenna array beamformer using new variable loading technique against steering vector error. Steering vector error is an important factor for practical implem...
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ISBN:
(纸本)9781728149349
This paper describes the performance of robust rectangular antenna array beamformer using new variable loading technique against steering vector error. Steering vector error is an important factor for practical implementation of the beamformer and the outcome of the paper shows that the robust beamformer performs well at erroneous and error free condition. rectangular array is essential for the modern space limited situation where the array can scan around 360 degrees and required less space for array elements positioning. The result of the technique is compared with other published loading technique applied to rectangular array.
This paper aims at investigating the feasibility of ranging and positioning in millimeter (mm)-level accuracy by adopting millimeter-wave and 3D massive antenna array. The agent is equipped with massive phased uniform...
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ISBN:
(纸本)9781538624111
This paper aims at investigating the feasibility of ranging and positioning in millimeter (mm)-level accuracy by adopting millimeter-wave and 3D massive antenna array. The agent is equipped with massive phased uniform rectangular array (URA) and multiple anchors are considered in localization networks to pursue a higher accuracy, where a far-field environment is assumed for phased massive URA. Fundamental limits of both time-based ranging and positioning are derived by Cramer-Rao bound (CRB), where the relationship between the fundamental bound of range estimation and that of position estimation is theoretically clarified. Numerical results show that the proposed scenario achieves a precise mm-level accuracy for ranging and positioning.
In order to efficiently estimate the angle of arrival (AOA) information from the closely located signal sources, in this paper, we introduce a cascade AOA estimation technique based on the CAPON and beamspace Multiple...
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ISBN:
(纸本)9781538653890;9788957083048
In order to efficiently estimate the angle of arrival (AOA) information from the closely located signal sources, in this paper, we introduce a cascade AOA estimation technique based on the CAPON and beamspace Multiple Signal Classification (MUSIC) algorithms. First, the cascade approach estimates AOA groups consisting of multiple AOAs using CAPON, and then estimates the individual AOA in the AOA group using beamspace MUSIC. In this paper, we employ the rectangular array anttena for the cascade algorithm.
Antenna array of two dipole antennas made of copper has been designed and analyzed for 0.1 THz frequency in this work for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{w...
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Antenna array of two dipole antennas made of copper has been designed and analyzed for 0.1 THz frequency in this work for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\frac{3\lambda }{4}$$\end{document} and d=lambda\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\lambda$$\end{document}, where lambda is the wavelength. Antenna length is lambda 2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{\uplambda }{2 }$$\end{document} and width is lambda 200.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{\uplambda }{200} .$$\end{document} Range of azimuth angle is [- 180 degrees-180 degrees] and elevation angle is [- 90 degrees-90 degrees]. Variation in correlation of power transmitted from first port to second port (S21) has been analyzed changing tilt variation of second dipole, inter element spacing and frequency. optimization of results antenna gain has been achieved as 5.41dBi and 6.35dBi for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\frac{3\lambda }{4}$$\end{document} and d=lambda\documentcla
James et al. have introduced a variant of P systems called parallel contextual array insertion deletion P system and studied some of its properties. The family of array languages generated by this variant of PCAIDPS i...
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James et al. have introduced a variant of P systems called parallel contextual array insertion deletion P system and studied some of its properties. The family of array languages generated by this variant of PCAIDPS includes families of array languages like recognisable picture languages (REC) and context-sensitive matrix languages L(CSMG). In this paper we show that another interesting family L(CF : RIR) of Siromoney matrix languages is included in the family of array languages generated by PCAIDPS with two membranes. [GRAPHICS] .
Siromoney et al. introduced Siromoney matrix grammars (1973) which are of sequential-parallel type in the sense that first a horizontal string of nonterminals is derived sequentially by applying the horizontal product...
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ISBN:
(纸本)9783030510015;9783030510022
Siromoney et al. introduced Siromoney matrix grammars (1973) which are of sequential-parallel type in the sense that first a horizontal string of nonterminals is derived sequentially by applying the horizontal production rules and then vertical productions are applied in parallel to get the intended two-dimensional picture. In 1999, Radhakrishnan et al. introduced and studied a variant of Siromoney matrix grammars called (X:Y)MG where X, Y is an element of {Context - Free(CF), Regular(R)}. James et al. in 2018 introduced Parallel Contextual array Insertion Deletion Grammar (PCAIDG) to generate two-dimensional array languages using insertion and deletion operations and parallel contextual mappings. In this paper, we prove that this family of languages generated by PCAIDGs properly includes the family (CF : CF) ML.
3D ultrasound imaging with 2D transducer arrays of large number of elements suffers from high hardware and computational complexity. In order to reduce the number of active channels, various sparse 2D array designs we...
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ISBN:
(纸本)9781728145969
3D ultrasound imaging with 2D transducer arrays of large number of elements suffers from high hardware and computational complexity. In order to reduce the number of active channels, various sparse 2D array designs were presented. However, the proposed designs so far have either irregular element distribution that cannot guarantee uniformity among the scan lines or lack of analysis. In this study, a generalized sparse rectangular array (SRA) is presented, and a design rule that avoids common grating lobes of the transmit and receive SRA pairs is derived by analyzing the beam patterns. The continuous wave (CW) and pulsed wave responses of the SRA pairs are simulated to verify the proposed design rule.
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