Journal articles: 'Locating array'

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Qi, Zong Feng, Wen Jie Zhong, and Yu Tang. "Bipartite Locating Array." Acta Mathematica Sinica, English Series 36, no. 2 (January 15, 2020): 179–88. http://dx.doi.org/10.1007/s10114-020-8522-2.

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Fang, Li Qing, Hong Kai Wang, and Kai Chen. "Design of Passive Acoustic Location System Based on Double Arrays." Advanced Materials Research 490-495 (March 2012): 1857–61. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.1857.

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The biggest advantage passive acoustic positioning system based on single array is that it has high performance on orientation. However, its positioning error is usually larger. Locating based on multi-array not only gives more information to enhance the locating accurate, but also can eliminate the blind area generated by single array. So its locating performance is better than single-base array. In this paper, taking the system of double arrays for instance, built a passive acoustic positioning system, gave the plan of the system, and designed the tests to compare the accuracy between the single array and double arrays. According to the tests, it further verified that locating system based on double arrays has higher accuracy than the system of single array. And it also has high value engineering.

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Wang, Xing Wang, Bing Yi Sun, Bin Li, Li Li He, and Cheng Quan Hu. "An Acoustic Source Localization Method Based on Equal Distances Multi-Sensors Array." Applied Mechanics and Materials 214 (November 2012): 856–61. http://dx.doi.org/10.4028/www.scientific.net/amm.214.856.

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The traditional acoustic source is sensitive to time. A novel sound source location method using linear intersection spacing multi-sensors array is provided in this paper. Each array is composed of three spaced nodes, and least squares method is used to calculate the final position according to ternary array results. Multi-arrays method is more robust than the ternary one, and much wider scope is covered. Location scope extends from 120m to 800m when the relative positioning error is 10%. A multi-array group based on linear intersection sound source localization method is provided in this paper too. Experiment results show that the proposed method has higher precision on angle locating than distance locating.

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Fang, Li Qing, Hong Kai Wang, and Kai Chen. "Analysis of Directional Accuracy of Three Single Arrays." Advanced Materials Research 490-495 (March 2012): 1714–17. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.1714.

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Acoustic sensoxr array technology is the one of the key technology of passive acoustic detection technology, whether the single array has a good performance on direction will directly affect the accuracy of the locating system. In order to choose the best single array on direction, in this paper, respectively selected representative plane array and spatial array from a number of typical single arrays to analyze, find out the advantages and disadvantages of two single arrays. On this basis, around the idea of integrating the advantage of symmetric spatial array and plane cross five-element array, according to characteristics of the structure of this two kinds of arrays to design a new locating model—spatial five-element array. And compared with two kinds of single array mentioned above, the results of comparison show that the locating accuracy of spatial five-elements array is superior to both kinds of mentioned, and have high engineering value.

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Fan, R. X., J. R. Miao, C. Zhao, and D. Xie. "Mismatch locating strategy of photovoltaic array." IOP Conference Series: Earth and Environmental Science 127 (March 2018): 012004. http://dx.doi.org/10.1088/1755-1315/127/1/012004.

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Cesbron, F., and R. Arnott. "Locating GSM mobiles using antenna array." Electronics Letters 34, no. 16 (1998): 1539. http://dx.doi.org/10.1049/el:19981090.

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Yin, Junhui, Chao Xiong, and Wenjie Wang. "Acoustic Localization for a Moving Source Based on Cross Array Azimuth." Applied Sciences 8, no. 8 (August 1, 2018): 1281. http://dx.doi.org/10.3390/app8081281.

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Acoustic localization for a moving source plays a key role in engineering applications, such as wildlife conservation and health protection. Acoustic detection methods provide an alternative to traditional radar and infrared detection methods. Here, an acoustic locating method of array signal processing based on intersecting azimuth lines of two arrays is introduced. The locating algorithm and the precision simulation of a single array shows that such a single array has good azimuth precision and bad range estimation. Once another array of the same type is added, the moving acoustic source can be located precisely by intersecting azimuth lines. A low-speed vehicle is used as the simulated moving source for the locating experiments. The length selection of short correlation and moving path compensation are studied in the experiments. All results show that the proposed novel method locates the moving sound source with high precision (<5%), while requiring fewer instruments than current methods.

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Buaka Muanke, Paulin, and Christopher Niezrecki. "Locating manatee position with an acoustic array." Journal of the Acoustical Society of America 119, no. 5 (May 2006): 3405. http://dx.doi.org/10.1121/1.4786762.

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Konishi, Tatsuya, Hideharu Kojima, Hiroyuki Nakagawa, and Tatsuhiro Tsuchiya. "Using simulated annealing for locating array construction." Information and Software Technology 126 (October 2020): 106346. http://dx.doi.org/10.1016/j.infsof.2020.106346.

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Werner, Claudia, and Erik H. Saenger. "Obtaining reliable source locations with time reverse imaging: limits to array design, velocity models and signal-to-noise ratios." Solid Earth 9, no. 6 (December 14, 2018): 1487–505. http://dx.doi.org/10.5194/se-9-1487-2018.

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Abstract. Time reverse imaging (TRI) is evolving into a standard technique for locating and characterising seismic events. In recent years, TRI has been employed for a wide range of applications from the lab scale, to the field scale and up to the global scale. No identification of events or their onset times is necessary when locating events with TRI; therefore, it is especially suited for locating quasi-simultaneous events and events with a low signal-to-noise ratio. However, in contrast to more regularly applied localisation methods, the prerequisites for applying TRI are not sufficiently known.To investigate the significance of station distributions, complex velocity models and signal-to-noise ratios with respect to location accuracy, numerous simulations were performed using a finite difference code to propagate elastic waves through three-dimensional models. Synthetic seismograms were reversed in time and reinserted into the model. The time-reversed wave field back propagates through the model and, in theory, focuses at the source location. This focusing was visualised using imaging conditions. Additionally, artificial focusing spots were removed using an illumination map specific to the set-up. Successful locations were sorted into four categories depending on their reliability. Consequently, individual simulation set-ups could be evaluated by their ability to produce reliable source locations.Optimal inter-station distances, minimum apertures, relations between the array and source locations, heterogeneities of inter-station distances and the total number of stations were investigated for different source depths and source types. Additionally, the accuracy of the locations was analysed when using a complex velocity model or a low signal-to-noise ratio.Finally, an array in southern California was investigated regarding its ability to locate seismic events at specific target depths while using the actual velocity model for that region. In addition, the success rate with recorded data was estimated.Knowledge about the prerequisites for using TRI enables the estimation of success rates for a given problem. Furthermore, it reduces the time needed to adjust stations to achieve more reliable locations and provides a foundation for designing arrays for applying TRI.

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ZHOU, Wu-Jie, De-Ping ZHANG, and Bao-Wen XU. "Locating Error Interactions Based on Partial Covering Array." Chinese Journal of Computers 34, no. 6 (September 6, 2011): 1126–36. http://dx.doi.org/10.3724/sp.j.1016.2011.01126.

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Hiranaka, Yukio, and Hiro Yamasaki. "LOCATING GAS SOURCES USING A GAS SENSOR ARRAY." Analytical Sciences 7, Supple (1991): 1565–68. http://dx.doi.org/10.2116/analsci.7.supple_1565.

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Zhang, Xiaojun, Xiyuan Kang, Xin Chen, Zhuoshan Geng, Liming Fan, Quan Zheng, Hua Lv, and Chong Kang. "Experimental Study on the Aperture of Geomagnetic Location Arrays." Journal of Sensors 2019 (March 7, 2019): 1–12. http://dx.doi.org/10.1155/2019/7491871.

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A method of locating a magnetic target based on geomagnetic total field is proposed. In the method, a conjugate gradient algorithm is introduced to eliminate the time-varying and uneven spatial distribution of geomagnetic total field. Then a structure of the measuring array of geomagnetic total field is designed. In the measuring array, the array aperture is a primary factor for the conjugate gradient algorithm. To determine an optimal aperture, we analyze the relationship between the array aperture and the localization accuracy. According to the localization theory based on geomagnetic total field, we simulate the process of determining an optimum array aperture. Based on the simulation, we propose the basis and principle of determining the optimum array aperture. To prove it, we use optically pumped magnetometers with different array apertures to carry out the experiments of locating a car in a suburb. Through the experiment, we get the experimental relationship between apertures and location accuracy. And the relationship agrees with the theory. The result shows that the method is feasible to determine the optimum aperture.

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Ramachandran, Rakesh C., Ganesh Raman, and Robert P. Dougherty. "Noise Source Localization Using a Compact Phased Array: Studies on a Full Scale Wind Turbine in a Wind Farm." Wind Engineering 36, no. 5 (October 2012): 589–604. http://dx.doi.org/10.1260/0309-524x.36.5.589.

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Locating the dominant noise sources on a wind turbine is an important problem in designing and developing low noise wind turbines. Previously very large microphone arrays were used to locate these sources. The primary focus of this paper is to show that using a compact and mobile microphone array with advanced beamforming algorithms, the noise sources can be successfully located and quantified. The results from the qualification experiments on the microphone array conducted in laboratory using synthetic noise sources show the differences between the various beamforming algorithms used in this study (both frequency and time domain algorithms). The initial experimental results on a full scale wind turbine reveal that it is indeed possible to locate the noise sources using a compact microphone array by successfully locating the two dominant noise sources on the wind turbine namely, aerodynamic noise near the blade tip and mechanical noise from nacelle.

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Chen, Peng-An, Hsiao-Fei Liu, and Kun-Mao Chao. "CNVDetector: locating copy number variations using array CGH data." Bioinformatics 24, no. 23 (November 7, 2008): 2773–75. http://dx.doi.org/10.1093/bioinformatics/btn517.

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Saribudak, Mustafa, Dale F. Rucker, and Allan Haas. "Electrical Resistivity Imaging near Abandoned Steel Oil Wells: Five Case Studies, USA." Journal of Environmental and Engineering Geophysics 25, no. 4 (December 2020): 545–56. http://dx.doi.org/10.32389/jeeg20-048.

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Abandoned wells may act as conduits for the contamination of groundwater by oil field brines and other pollutants. The steel casings of abandoned wells eventually develop leaks, which if not properly plugged, can allow pollutants to reach freshwater aquifers that supply drinking water. Resistivity surveys were conducted in the vicinity of five abandoned oil wells in order to characterize the near-surface geology and to determine the effects of the steel casings and potential leakage. The arrays consisted of dipole-dipole (DD) and inverse Schlumberger (SLB) arrays. The effects from steel cased wells can manifest as low resistivity anomalies in the vicinity of the casings, depending on proximity of the line to the well, well location along the line, and the specific array used. These features appear as vertical, circular, elliptical, and bell-like anomalies. However, in some instances with the SLB array, the data appear not to be affected by the presence of steel casings. This observation is significant because resistivity surveys utilizing the SLB array can provide reliable information on near-surface geology next to abandoned wells, and horizontal and vertical extension of brine impacted areas due to leaking abandoned oil wells. The DD array, on the other hand, is better at locating potentially hidden abandoned wells but interpreting subsurface structure or contamination with the array is more difficult.

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Chen and Shin. "An Improved Impact Source Locating System Using FBG Rosette Array." Sensors 19, no. 16 (August 7, 2019): 3453. http://dx.doi.org/10.3390/s19163453.

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For structures vulnerable to foreign object impact damages, it would be desirable to detect and locate any occurrence of such impacts. This can be achieved by monitoring the stress waves generated by an impact together with certain source localization algorithms. Being small, electromagnetic influence immune and durable, Fiber Bragg grating (FBG) sensors are advantageous for this task. One drawback of FBGs for this purpose is their uneven directional sensitivity, which limits its localization ability to within 50° on either side of the fiber axis. Beyond this range, the signal is too weak and masked by noises and the location errors increase abruptly. Two approaches have been tested on a 0.8 m × 0.8 m × 6 mm plate for possible improvement on the system accuracy: firstly, an interrogation scheme with stronger light source intensity and steeper edge filter is employed to enhance the signal-to-noise ratio and system sensitivity; secondly, rosettes with two orthogonal FBGs are cascaded together to replace single FBGs to alleviate the directional sensitivity problem. It was found that a four-fold increase in signal to noise ratio contributed by stronger light source does improve the location accuracy, but only marginally. For the rosette approach, the relative positions of the Bragg wavelength of the FBGs and the light source spectrum are crucial to accuracy. Three different wavelength configurations have been tested and the reasons for their success or failure are discussed. It was shown that with an optimal wavelength configuration, the rosette array can virtually extend the good location accuracy to all over the plate.

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Li, Hongyi, and Lupei Zhu. "Locating Small Aftershocks Using a Small-Aperture Temporary Seismic Array." Pure and Applied Geophysics 168, no. 10 (November 10, 2010): 1707–14. http://dx.doi.org/10.1007/s00024-010-0213-y.

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Wang, Ke, Facundo Bob Varela, and Mike Yongjun Tan. "An Array of Multielectrodes for Locating, Visualizing, and Quantifying Stray Current Corrosion." Corrosion 74, no. 10 (June 24, 2018): 1093–101. http://dx.doi.org/10.5006/2828.

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An array of multielectrode corrosion probes, designed based on a series of coupled wire beam electrodes (WBEs), has been devised as a new tool for locating, visualizing, and quantifying the effects of stray currents on buried pipeline corrosion. It has been demonstrated in laboratory simulation experiments that this WBE probe array is capable of detecting stray current corrosion affected sites along a pipeline, visualizing stray current corrosion patterns and corrosion rates, and evaluating the efficiency of cathodic protection against stray current corrosion. Based on these results, two applications of this WBE probe array have been proposed for stray current corrosion survey and monitoring.

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Fang, Zhou, and Peter W. Tse. "Demagnetization-based axial magnetized magnetostrictive patch transducers for locating defect in small-diameter pipes using the non-axisymmetric guided wave." Structural Health Monitoring 18, no. 5-6 (March 5, 2019): 1738–60. http://dx.doi.org/10.1177/1475921719833471.

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The propagation of the non-axisymmetric guided wave in the small-diameter pipe is complicated, which makes the circumferential position of the defect difficult to be determined. This article reports on the design of a segmented axially magnetized magnetostrictive patch transducer array for efficient transduction of non-axisymmetric L(M,2) modes to determine defect’s axial and circumferential positions in the small-diameter pipe. First, the background of the magnetostrictive patch transducer and non-axisymmetric guided wave in the pipe was presented. Moreover, the theoretical background to the influence of the length-to-width ratio of the magnetized rectangular patch on the demagnetizing factors was introduced. Second, the method of the pipe health monitoring using the designed segmented axially magnetized magnetostrictive patch transducer array was proposed. Third, the most suitable multi-belts of the flexible printed coils were chosen to provide the dynamic magnetic field by the comparison experiments. Then the signal amplitudes of the segmented axially magnetized magnetostrictive patch transducer array with different length–width ratios of magnetostrictive materials were compared with each other to prove the principle of demagnetization. Another two magnetostrictive patch transducer arrays employing permanent magnets were compared with the proposed segmented axially magnetized magnetostrictive patch transducer array. The experiments of pipe health monitoring were carried out to prove that the proposed method can realize pipe health monitoring over time. Fourth, the defect orientation experiments in a 304 stainless steel pipe with 48 mm inner diameter and 2 mm thickness were performed using the proposed segmented axially magnetized magnetostrictive patch transducer array at 650 kHz. The prediction of the circumferential position of the defects correlated well with the defect’s true location through matching the angular profiles of the experimental results and the modulated numerical analysis for several axial distances. The experimental results for the segmented axially magnetized magnetostrictive patch transducer array demonstrated that the proposed segmented axially magnetized magnetostrictive patch transducer array could potentially be applied to detect the axial and circumferential positions of the defect in a small-diameter pipe.

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Liu, Zhihong, Xilong Zhang, Zunmin Liu, Chuijie Yi, and Ming Ma. "A Partition Spatial Filtering Method for Acoustic Array Configuration." Shock and Vibration 2021 (February 11, 2021): 1–18. http://dx.doi.org/10.1155/2021/6682923.

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Acoustic array is a ubiquitous tool for locating and quantifying sound sources. However, its effectiveness depends greatly on the array configuration. This paper presents an array configuration method to enhance array performance, especially on the spatial resolution and the Doppler effect correction. The problem of array configuration is formulated into a position matrix determined by introducing partition spatial filtering. Irregular coaxial ring grid spacings and partition filtering conditions are suggested to control array spatial resolution. Geometrical parameters and performance indicators are constructed to quantify the relationships between the array configuration and performance. Based on these quantitative relations, the spatial variation of the array beam pattern and the Doppler effect has got adaptive adjustment. In particular, an adaptive partition algorithm is proposed to reduce computation time. The performance of the method is examined numerically and experimentally, which is compared with the other methods. The results provide the method to guide the design of a 64-microphone optimized array with high performance (1.8° spatial angle resolution and 40% Doppler frequency correction over the bandwidth from 800 Hz to 3000 Hz) and fast computing speed (18 s array generated time for 2000 arrays). Furthermore, an unusual feature of the method is that it can be utilized in the case when the source moves at a nonconstant velocity.

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Zhang, Cui Qing, Zhi Ying Gao, Yongyan Chen, Wen chun Lv, Jin xia Chen, and Yuntao Liu. "Experimental locating of rotor sound source using a compact microphone array." Journal of Renewable and Sustainable Energy 12, no. 5 (September 2020): 053303. http://dx.doi.org/10.1063/5.0003236.

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Duncan, Peter M., and Leo Eisner. "Reservoir characterization using surface microseismic monitoring." GEOPHYSICS 75, no. 5 (September 2010): 75A139–75A146. http://dx.doi.org/10.1190/1.3467760.

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Microseismic monitoring of reservoir processes can be performed using surface or near-surface arrays. We review the published technical basis for the use of the arrays and the historical development of the method, beginning with locating earthquakes through geothermal exploration to the growing field of hydraulic-fracture monitoring. Practical considerations for the array deployment and data processing are presented. The road ahead for the technology includes a move toward life-of-field buried arrays as well as opportunities for extended interpretation of the data, particularly inversion for source-mechanism estimation and measurement of anisotropy in the monitored subsurface.

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Chen, Huawei, and Junwei Zhao. "On locating low altitude moving targets using a planar acoustic sensor array." Applied Acoustics 64, no. 11 (November 2003): 1087–101. http://dx.doi.org/10.1016/s0003-682x(03)00073-2.

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Ding, Hao, Yumei Bao, Qi Huang, Chunxiao Li, and Guozhong Chai. "Three-dimensional localization of point acoustic sources using a planar microphone array combined with beamforming." Royal Society Open Science 5, no. 12 (December 2018): 181407. http://dx.doi.org/10.1098/rsos.181407.

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This paper presents a beamforming-based acoustic imaging (BBAI) method employing a two-dimensional (2D) microphone array that not only can locate an acoustic source in the XY plane parallel to the array, but can also identify the distance between the source and array in the Z direction, denoted as the source depth, and thus provides three-dimensional (3D) localization ability. In this method, the acoustic field is reconstructed on virtual XY planes at different distances along the Z direction. The source depth is then determined according to the virtual plane providing the maximum response of the acoustic field. The location of the source in the X and Y directions of the identified virtual plane can then be easily determined based on the standard beamforming principles of a planar array. The proposed BBAI method is evaluated based on simulations involving single- and multiple-point sources, and corresponding experimental evaluations are similarly conducted in an anechoic chamber. Both simulation and experimental results demonstrate that the proposed method is capable of locating acoustic sources in 3D space.

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Zhu, Guolei, Yingmin Wang, and Qi Wang. "Research on Accurate Ultrasonic Positioning Error under the Special Environment." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 36, no. 3 (June 2018): 496–501. http://dx.doi.org/10.1051/jnwpu/20183630496.

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This paper studies how to achieve the accurate position by an ultrasonic positioning system, which is for locating the autonomous vehicle in a special giant spherical container. A localization method using the least squares with a plane array which consists of four elements is proposed, the reason that causes the location error is analysed, and the relationship among the target distance and the array shape and the error of the ultrasonic positioning system is studied by Monte Carlo simulations. Finnally, in order to verify the positioning effect, the positioning experiment is done in an anechoic tank, the experimental results shown that when the ranging error is less than 20 mm, the positioning accuracy of x-y plane is less than about 30 mm.

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Nakatani, Hayato, Talieh Hajzargarbashi, Kaita Ito, Tribikram Kundu, and Nobuo Takeda. "Locating Point of Impact on an Anisotropic Cylindrical Surface Using Acoustic Beamforming Technique." Key Engineering Materials 558 (June 2013): 331–40. http://dx.doi.org/10.4028/www.scientific.net/kem.558.331.

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A beamforming array technique with four sensors is applied to a cylindrical geometry for detecting point of impact. A linear array of acoustic sensors attached to the plate record the waveforms of Lamb waves generated at the impact point with individual time delay. A beamforming technique in conjunction with an optimization scheme that incorporates the direction dependent guided Lamb wave speed in cylindrical plates is developed. The optimization is carried out using the experimentally obtained wave speed as a function of propagation direction. The maximum value in the beamforming plot corresponds to the predicted point of impact. The proposed technique is experimentally verified by comparing the predicted points with the exact points of impact on a cylindrical aluminum plate and a cylindrical composite shell. For randomly chosen points of impact the beamforming technique successfully predicts the location of the acoustic source.

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Youhuan, NING, and ZHANG Wenbin. "Research on Locating Algorithm of Unmanned Airport Source Based on Array Detecting Line." Journal of Physics: Conference Series 1325 (October 2019): 012153. http://dx.doi.org/10.1088/1742-6596/1325/1/012153.

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Duan, Chenglong, David Lumley, and Hejun Zhu. "Estimation of micro-earthquake source locations based on full adjoint P and S wavefield imaging." Geophysical Journal International 226, no. 3 (June 3, 2021): 2116–44. http://dx.doi.org/10.1093/gji/ggab203.

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SUMMARY Locating micro-earthquakes with high resolution and accuracy is a challenge for traveltime inversion, which has uncertainty on the order of a Fresnel zone (many wavelengths). We develop a wave-equation imaging method to increase resolution and reduce location errors to less than a wavelength, but requires very densely deployed receiver arrays with wide aperture and considerable computational cost. Instead of using acoustic data or direct P wave arrivals only, we use elastic multicomponent data and present a new method that uses the full P and S adjoint wavefields to image the microseismic source locations. We separate the P and S waves from the data, and extrapolate the P and S wavefields of each receiver subarray by solving the P and S adjoint wave equations in parallel. We formulate three source imaging conditions by multiplying over subarrays the adjoint P wavefield (IP), S wavefield (IS) and cross-correlated P and S wavefields (IPS). We perform numerical experiments on the highly realistic SEG SEAM4D reservoir model using surface acquisition array geometries. Results for 2-D and 3-D microseismic source estimations show clean images without noisy artefacts at shallow depths. In particular, IPS provides the highest resolution source location image, while IP is limited by the P wavelength and IS is influenced by small coda artefacts. The major-axis alignment and resolution of the source location image are determined by the hypocentral location with respect to the receiver array and illumination-angle coverage, respectively. We discuss the impacts of S-wave attenuation and frequency bandwidth on the source location images. Noise tests indicate that the imaging results are relatively insensitive to ambient noise, as is observed for the surface monitoring data. Using smoothed velocity models, the imaging results are similar to the results using the true realistically heterogeneous velocity model. The 90 per cent confidence ellipse of the source location due to Gaussian-distributed velocity errors shows a larger depth error as the source becomes deeper, while the horizontal error does not change as much.

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Lee, Jong-Hwan, Jeung-Min Joo, Kichul Kim, Jung-Hoon Lee, and Young-Ju Park. "Practical Consideration Factors to Design Array Configuration of Direction Finding System for Airborne Signal Intelligence." Security and Communication Networks 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/9185760.

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Airborne signal intelligence (SIGINT) systems must be capable of locating radio signal sources. Direction finding (DF) to support this capability is an important factor. There are some practical considerations to be taken when designing the array configuration of a DF system for airborne SIGINT systems. This paper summarizes the practical factors when designing the array configuration of the DF system for airborne SIGINT. In particular, it focuses on four areas: antenna consideration factors when installing the DF system for airborne SIGINT from a practical point of view, array configuration methods for airborne communications intelligence and electronic intelligence, and a numerical analysis to select the optimum antenna position for airborne SIGINT.

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Cabieces, Roberto, Frank Krüger, Araceli Garcia-Yeguas, Antonio Villaseñor, Elisa Buforn, Antonio Pazos, Andrés Olivar-Castaño, and Jaime Barco. "Slowness vector estimation over large-aperture sparse arrays with the Continuous Wavelet Transform (CWT): application to Ocean Bottom Seismometers." Geophysical Journal International 223, no. 3 (September 9, 2020): 1919–34. http://dx.doi.org/10.1093/gji/ggaa427.

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SUMMARY This work presents a new methodology designed to estimate the slowness vector in large-aperture sparse Ocean Bottom Seismometer (OBS) arrays. The Continuous Wavelet Transform (CWT) is used to convert the original incoherent traces that span a large array, into coherent impulse functions adapted to the array aperture. Subsequently, these impulse functions are beamformed in the frequency domain to estimate the slowness vector. We compare the performance of this new method with that of an alternative solution, based on the Short-/Long-Term Average algorithm and with a method based on the trace envelope, with the ability to derive a very fast detection and slowness vector estimation of seismic signal arrivals. The new array methodology has been applied to data from an OBS deployment with an aperture of 80 km and an interstation distance of about 40 km, in the vicinity of Cape Saint Vincent (SW Iberia). A set of 17 regional earthquakes with magnitudes 2 < mbLg < 5, has been selected to test the capabilities of detecting and locating regional seismic events with the Cape Saint Vincent OBS Array. We have found that there is a good agreement between the epicentral locations obtained previously by direct search methods and those calculated using the slowness vector estimations resulting from application of the CWT technique. We show that the proposed CWT method can detect seismic signals and estimate the slowness vector from regional earthquakes with high accuracy and robustness under low signal-to-noise ratio conditions. Differences in epicentral distances applying direct search methods and the CWT technique are between 1 and 21 km with an average value of 12 km. The backazimuth differences range from 1° to 7° with an average of 1.5° for the Pwave and ranging from 1° to 10° with an average of 3° for the Swave.

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Sarwar, Mirza Saquib, Yuta Dobashi, Claire Preston, Justin K. M. Wyss, Shahriar Mirabbasi, and John David Wyndham Madden. "Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array." Science Advances 3, no. 3 (March 2017): e1602200. http://dx.doi.org/10.1126/sciadv.1602200.

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Zhang, Qiang, Chengrong Li, Shusheng Zheng, Haiyang Yin, Yanbang Kan, and Jun Xiong. "Remote detecting and locating partial discharge in bushings by using wideband RF antenna array." IEEE Transactions on Dielectrics and Electrical Insulation 23, no. 6 (December 2016): 3575–83. http://dx.doi.org/10.1109/tdei.2016.005747.

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Ding, Liang, Qin-ya Liu, Er-gen Gao, Wei Qian, and Shou-cai Sun. "Locating microseismic sources based upon L-shaped single-component geophone array: A synthetic study." Journal of Central South University 27, no. 9 (September 2020): 2711–25. http://dx.doi.org/10.1007/s11771-020-4493-9.

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Pelled, O., S. Tsroya, U. German, G. Haquin, and Z. B. Alfassi. "Locating a “hot spot” in the lungs when using an array of four HPGe detectors." Applied Radiation and Isotopes 61, no. 2-3 (August 2004): 107–11. http://dx.doi.org/10.1016/j.apradiso.2004.03.029.

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Zheng, Sifa, Feng Xu, Xiaomin Lian, Yugong Luo, Diange Yang, and Keqiang Li. "Generation method for a two-dimensional random array for locating noise sources on moving vehicles." Noise Control Engineering Journal 56, no. 2 (2008): 130. http://dx.doi.org/10.3397/1.2920703.

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Cao, Aimin, and Barbara Romanowicz. "Locating scatterers in the mantle using array analysis of PKP precursors from an earthquake doublet." Earth and Planetary Science Letters 255, no. 1-2 (March 2007): 22–31. http://dx.doi.org/10.1016/j.epsl.2006.12.002.

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THOMSON, DAVID J., and GORDON R. EBBESON. "A PE-BASED APPROACH TO MODAL DECOMPOSITION AND SOURCE LOCALIZATION." Journal of Computational Acoustics 02, no. 03 (September 1994): 231–50. http://dx.doi.org/10.1142/s0218396x94000166.

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Matched mode processing is an efficient alternative to matched field processing for locating a source in an acoustic waveguide. The successful application of this method relies on the accurate modal decomposition of the pressure data received on a vertical line array. From the modes that can be resolved by a given array aperture, the source range is determined from modal phases, whereas the source depth is determined from the mode shapes. In this paper, we describe a decomposition method based on the parabolic equation (PE) propagation model for recovering this modal information from vertical array data and which can be used to localize an underwater source by the matched mode processing method. We apply our PE-based decomposition/localization scheme to several benchmark problems involving a narrowband acoustic source operating in a shallow water environment.

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39

Yan, Shuan, Hongyong Yuan, Yan Gao, Boao Jin, Jennifer M. Muggleton, and Lizheng Deng. "On Image Fusion of Ground Surface Vibration for Mapping and Locating Underground Pipeline Leakage: An Experimental Investigation." Sensors 20, no. 7 (March 29, 2020): 1896. http://dx.doi.org/10.3390/s20071896.

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This paper is concerned with imaging techniques for mapping and locating underground pipeline leakage. Ground surface vibrations induced by the propagating axisymmetric wave can be measured by an array of acoustic/vibration sensors, with the extraction of magnitude information used to determine the position of leak source. A method of connected graph traversal is incorporated into the vibroacoustic technique to obtain the spatial image with better accuracy compared to the conventional magnitude contour plot. Measurements are made on a dedicated cast iron water pipe by an array of seven triaxial geophones. The spectral characteristics of the propagation of leak noise signals from underground water pipes to the ground surface are reported. Furthermore, it is demonstrated that suspicious leakage areas can be readily identified by extracting and fusing the feature patterns at low frequencies where leak noise dominates. The results agree well with the real leakage position in the underground pipeline.

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Kennett, Michael I. "A Possible Radio-Echo Method of Locating Englacial and Subglacial Waterways." Annals of Glaciology 13 (1989): 135–39. http://dx.doi.org/10.1017/s0260305500007771.

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An array of radio echoes has been collected on Storglaciären in Sweden and used in an aperture-synthesis experiment. The digitized echoes were combined in a computer with suitable time shifts to focus on regions beneath the ice surface. The positions of six individual englacial cavities have been found, and the echoes from them isolated for interpretation. By performing the aperture synthesis with data sets from three different antenna configurations, information on the cavity shapes and orientations has been derived. At least five of the cavities are believed to be water-filled, and may be parts of an englacial drainage system. The technique could be applied to the problem of finding the principal water channel(s) in or under a glacier. Successful location would be of considerable importance in the planning of subglacial water intakes for hydro-electric power production.

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Kennett, Michael I. "A Possible Radio-Echo Method of Locating Englacial and Subglacial Waterways." Annals of Glaciology 13 (1989): 135–39. http://dx.doi.org/10.3189/s0260305500007771.

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An array of radio echoes has been collected on Storglaciären in Sweden and used in an aperture-synthesis experiment. The digitized echoes were combined in a computer with suitable time shifts to focus on regions beneath the ice surface. The positions of six individual englacial cavities have been found, and the echoes from them isolated for interpretation. By performing the aperture synthesis with data sets from three different antenna configurations, information on the cavity shapes and orientations has been derived. At least five of the cavities are believed to be water-filled, and may be parts of an englacial drainage system. The technique could be applied to the problem of finding the principal water channel(s) in or under a glacier. Successful location would be of considerable importance in the planning of subglacial water intakes for hydro-electric power production.

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42

Hu, Gangyi, Shaojie Chen, Chaofeng Chen, Shuangmiao Zhai, and Shaoping Zhou. "An improved discrete elliptic imaging algorithm based on guided waves for defect localisation in curved plates." Insight - Non-Destructive Testing and Condition Monitoring 61, no. 11 (November 1, 2019): 656–62. http://dx.doi.org/10.1784/insi.2019.61.11.656.

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Many effective image-based algorithms are available for detecting and locating defects in flat plate-like structures. However, there are few studies on image-based algorithms for curved plate structures. An improved method is proposed in this article, which is based on the discrete elliptic imaging algorithm and the improved signal normalisation method. To verify its effectiveness, experiments using a circular array are conducted on curved plates with different degrees of bending. The experimental results show that the improved method can accurately locate defects in curved plates and, compared with the original discrete elliptic imaging algorithm, its range of error in locating a single defect is reduced from 20.2-33.3 mm to 2.7-5.1 mm.

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Cui, Ke, Zhongjie Ren, Jieyu Qian, Wenjun Peng, and Rihong Zhu. "Precisely Automatic Time Window Locating for an Interferometric Fiber-Optic Sensor Array Based on a TDM Scheme." Sensors 18, no. 10 (October 19, 2018): 3548. http://dx.doi.org/10.3390/s18103548.

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Interferometric fiber-optic sensors are often organized in the form of large-scale arrays by lending the technique of time division multiplexing (TDM) to reduce the system cost. Discriminating the time windows for different sensor units is the prerequisite to successfully demodulate the sensing message, but it traditionally calls for a very time-consuming manual calibration process. To combat this problem, a novel automatic time window locating method is proposed in this paper. It introduces the concept of shape function and carries out the cross-correlation operation between the shape function and the sensor signal. The shape function is defined as the function whose curve profile reflects the main data characteristics of the sensor signal. The time window information is then extracted from the correlation result. This whole process is carried out automatically by the interrogation controller of the sensor system without any manual intervene. Experiments are conducted to validate this method. The proposed method can greatly reduce the complexity of locating time windows in large-scale TDM sensor arrays, and make the practical use of the TDM scheme much more convenient.

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Hirabayashi, Nobuyasu. "Real-time event location using model-based estimation of arrival times and back azimuths of seismic phases." GEOPHYSICS 81, no. 2 (March 1, 2016): KS25—KS40. http://dx.doi.org/10.1190/geo2014-0357.1.

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I have devised a real-time procedure for locating events using an estimation method that analyzes arrival times and back azimuths of phases. The new procedure is applicable to data acquired by local array receivers, such as those used in single-well monitoring as well as by dense receiver networks, and also to noisy waveforms, such as those observed in hydraulic fracturing monitoring if the signal-to-noise ratio is greater than approximately 6 dB. The new procedure uses coalescence microseismic mapping to obtain predictions of arrival times. Based on these predictions, arrival times were estimated by picking the maximum of the ratio of the short-term average to the long-term average of a characteristic function computed for waveforms in an appropriate time window. The estimated arrival times were used in a probabilistic location method, and the probability density function (PDF) of the event location was generated. To locate events for a local array of receivers, the PDFs of event back azimuths obtained using polarizations were combined with the traveltime data to remove directional ambiguities. I have developed this method to generate the PDF of event back azimuths using the average of polarization misfits, which are the differences of the measured and computed polarizations for trial event locations, weighted by the signal-to-noise ratio. Synthetic and field data examples of single-well monitoring of hydraulic fracturing, which required the estimation of event back azimuths in addition to arrival times, were evaluated to determine the effectiveness of the new procedure.

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Shehadeh, M., J. A. Steel, and R. L. Reuben. "Acoustic Emission Source Location for Steel Pipe and Pipeline Applications: The Role of Arrival Time Estimation." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 220, no. 2 (May 1, 2006): 121–33. http://dx.doi.org/10.1243/095440806x78829.

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Acoustic emission (AE) can be generated by a number of different fault conditions in pipes, including localized fluid-mechanical disturbances, such as local impingement or erosion, growing fatigue cracks or crack face rubbing, external impacts and leaks, each of which may have its own temporal and frequency characteristics. In this paper, a linear array of sensors is applied with the ultimate aim of locating and reconstituting the time-domain and frequency-domain signatures of AE sources in pipes. Experiments have been carried out with a simulated source on sections of line pipe and process pipe using a linear array. The acquired signals have two identifiable components and methods are demonstrated for separating these components automatically and determining their group velocities. A range of techniques, including a wavelet transform technique, a cross-correlation technique, and a filtering and thresholding technique are applied to obtain arrival times for various modes of the signal. Finally, methods are proposed for giving automatic source location in large length-diameter ratios with an accuracy of better than 5 per cent.

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Ryberg, T., Ch Haberland, G. S. Fuis, W. L. Ellsworth, and D. R. Shelly. "Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique." Geophysical Journal International 183, no. 3 (October 14, 2010): 1485–500. http://dx.doi.org/10.1111/j.1365-246x.2010.04805.x.

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Barlow, Jay, Emily T. Griffiths, and Holger Klinck. "Estimating geo-position and depth of echo-locating beaked whales using an array of drifting recorders." Journal of the Acoustical Society of America 141, no. 5 (May 2017): 3605. http://dx.doi.org/10.1121/1.4987717.

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48

Ge, Chang. "Numerical Simulation of Vibration Deflection Effects on the Energy Efficiency of Ultrasonic Transducer for Sonochemistry." Mathematical Problems in Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/591352.

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The energy efficiency of ultrasound transducers for sonochemistry applications was studied from the point of view of vibration deflection effects of different transducer structures, including the configurations of rectangular plate, cylindrical shell, triangular strip array, rectangular strip array, and pentagonal strip array. It was found that the deflections are not uniform over the transducer surface with the maximum deflection locating at the geometry center of transducers. The simulated maximum deflection of rectangular plate results in the value of2.5×10-16, which is larger than the maximum deflection of cylindrical shell with the value of2×10-16. This finding suggests that the envelope deflection volume of two transducers has significant difference, which has been neglected in the design and selection of ultrasound transducer. For this reason, a quantitative index involving the envelope deflection volume was proposed to compare the efficiency of ultrasound transducers. Based on the simulation results, the triangular strip array transducer structure with higher ultrasound generation efficiency was proposed, which was also theoretically validated by the MATLAB simulation.

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Peng, Jiansheng, Yiyong Huang, and Guan Luo. "Robot Path Planning Based on Improved A* Algorithm." Cybernetics and Information Technologies 15, no. 2 (June 1, 2015): 171–80. http://dx.doi.org/10.1515/cait-2015-0036.

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AbstractDue to the characteristic that A* algorithm takes a long time when traversing an OPEN table and a CLOSED table, an improved method is proposed that is a new way of array storing in an OPEN table and a CLOSED table. Compared to the original A* algorithm, the way of array storing accesses the array elements by locating the number ranks each time you visit a specified element, which can be done by only one operation. The original A* algorithm requires the traverse of multiple nodes in order to find a specified element. The experimental results show that the comparison of the improved A* algorithm with the original A* algorithm shows that the operating efficiency is improved by more than 40%. Based on the improved A* algorithm the method preserves the advantages of the original A* algorithm, improving the operating efficiency of A* algorithm.

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Ni, Shuyan, Jianhua Cui, Naiping Cheng, and Yurong Liao. "Detection and elimination method for deception jamming based on an antenna array." International Journal of Distributed Sensor Networks 14, no. 5 (May 2018): 155014771877446. http://dx.doi.org/10.1177/1550147718774466.

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A global positioning system is an important way of locating an aircraft, while deception jamming can affect the positioning accuracy of such navigation. Considering this, a detection and elimination method for deception jamming is proposed based on a specially designed array for the aircraft. The jamming is detected by comparing the double-difference observation of the carrier phases of two different signals to a certain threshold derived according to the measurement errors of the receiver. To estimate the jamming direction with high accuracy, meanwhile considering the feasibility of airborne installation, a novel configurated array combining medium-length baseline with short baseline is designed, and a fast method to solve the integer ambiguity is discussed. After jamming detection, the nulling of the array beam is pointed to the jamming source through the orthogonal vector weighting to suppress jamming. The validity of the method is verified by computer simulations.

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Journal articles on the topic 'Locating array'

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