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Journal articles on the topic 'Towed Array Model'

Author: Grafiati

Published: 6 September 2023

Last updated: 31 July 2025

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1

Sullivan, Edmund J. "Model‐based towed array processing." Journal of the Acoustical Society of America 101, no. 5 (1997): 3156. http://dx.doi.org/10.1121/1.419142.

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Sullivan, Edmund J., and Geoffrey S. Edelson. "Model‐based broadband towed‐array processing." Journal of the Acoustical Society of America 115, no. 5 (2004): 2577. http://dx.doi.org/10.1121/1.4784220.

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3

Jing, Yun, Rongjun Kang, Jian Ma, Sitong Liu, and Yongwei Liu. "Study on self-noise suppression technique inside towed line array." Journal of Physics: Conference Series 3007, no. 1 (2025): 012071. https://doi.org/10.1088/1742-6596/3007/1/012071.

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Abstract Towed line array is an important equipment for long-range detection, but its self-noise seriously affects detection performance. In this paper, a jet release method based on fish slime is proposed to reduce the hydrodynamic noise of towed arrays. The purpose of this method is to reduce the adverse effect of the turbulent pulsating pressure generated by high-speed towed arrays on self-noise and to solve the problem of target signal masking caused by water current noise. An annular nozzle is installed at the front end of the towed array, and slime is sprayed backwards to reduce the turb

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4

Sullivan, Edmund J., Dieter Brecht, and Leif Persson. "Model‐based towed array processor: Experimental results." Journal of the Acoustical Society of America 107, no. 5 (2000): 2890. http://dx.doi.org/10.1121/1.428744.

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5

Premus, Vincent E., Philip A. Abbot, Vitaly Kmelnitsky, Charles J. Gedney, and Ted A. Abbot. "A wave glider-based, towed hydrophone array system for autonomous, real-time, passive acoustic marine mammal monitoring." Journal of the Acoustical Society of America 152, no. 3 (2022): 1814–28. http://dx.doi.org/10.1121/10.0014169.

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An autonomous surface vehicle known as a wave glider, instrumented with a low-power towed hydrophone array and embedded digital signal processor, is demonstrated as a viable low-noise system for the passive acoustic monitoring of marine mammals. Other key design elements include high spatial resolution beamforming on a 32-channel towed hydrophone array, deep array deployment depth, vertical motion isolation, and bandwidth-efficient real-time acoustic data transmission. Using at-sea data collected during a simultaneous deployment of three wave glider-based acoustic detection systems near Stellw

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6

Jung, Youngcheol, Woojae Seong, Keunhwa Lee, and Seongil Kim. "A Depth-Bistatic Bottom Reverberation Model and Comparison with Data from an Active Triplet Towed Array Experiment." Applied Sciences 10, no. 9 (2020): 3080. http://dx.doi.org/10.3390/app10093080.

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In this paper, a depth-bistatic bottom reverberation model that employs the ray theory is presented. The model can be applied to an active towed array in the ocean. The reverberation time series are modeled under the depth-bistatic assumption and their Doppler shift is calculated based on the actual source–receiver geometry. This model can handle N × 2D range-dependent bathymetry, the geometry of a triplet array, and the Doppler motion of the source, targets, and receiver. The model predictions are compared with the mid-frequency reverberation data measured by an active triplet towed array dur

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Zhang, Dapeng, Bowen Zhao, and Keqiang Zhu. "Hydrodynamic Response of Ocean-Towed Cable-Array System under Different Munk Moment Coefficients." Sustainability 14, no. 3 (2022): 1932. http://dx.doi.org/10.3390/su14031932.

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The ocean towing system plays an important role in the ocean development process. The motion of a towed body is closely coupled with the motion of a towing cable. In this paper, the lumped mass method is used to discrete a towing cable into a lumped mass model. At the same time, on the basis of some assumptions, the relationship between the expression of Munk moments in the classical towed body kinematics and the expression of the Munk moments in the hydrodynamic analysis software OrcaFlex is established. Based on the above assumptions and the derivation, combined with the specific parameters

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Su, Zhaohua, Jie Zhuo, and Chao Sun. "Modeling and Data Analysis of Bistatic Bottom Reverberation from a Towed Horizontal Array." Remote Sensing 17, no. 2 (2025): 192. https://doi.org/10.3390/rs17020192.

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The spatial-temporal structures of bottom reverberation are associated with seafloor features. In a bistatic bottom reverberation experiment involving a vertical transmitting array and a towed horizontal receiving array, stable stripe structures were observed within the beam-time domain. In this study, a bistatic reverberation model based on ray theory is presented to interpret the experimental phenomena. The conventional empirical scattering function is primarily applicable to small grazing angles. Moreover, the regional segmentation method simulates reverberations across various receiving be

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9

Morten, Jan Petter, Jean-Michael Poudroux, and Rune Mittet. "A modeling study of augmenting coarse-grid 3D controlled-source electromagnetics with data from a towed receiver array." GEOPHYSICS 81, no. 1 (2016): E33—E42. http://dx.doi.org/10.1190/geo2014-0583.1.

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We have considered the simultaneous 3D inversion of controlled-source electromagnetic data from a towed receiver array and a coarse grid of stationary seabed receivers. Our 3D synthetic model demonstrated the sensitivity and effect on imaging of towed and seabed receiver data. The short-offset data from the towed receivers at 1–3 km offset are effective at resolving a shallow resistor at a 400-m burial depth. On the other hand, the data from the stationary seabed receivers have less noise and will resolve the 3D geometry of resistive structures buried at the 1–2 km depths typical of a hydrocar

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10

Hui, Juan, An Bang Zhao, Kun Ping Sun, Shao Juan Wen, and Jun Ying Hui. "The Simulation of Tow Ship Noise on Towed Linear Array." Advanced Materials Research 433-440 (January 2012): 2706–11. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.2706.

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Based on the acoustical properties of the tow ship noise, this paper studies the effect of tow ship noise on the towed linear array sonar system by computer simulation. The tow ship noise which is fairly approximate to the truth tow ship noise is obtained by the typical mathematical mode simulation firstly. Then the near-filed characteristics of the tow ship noise are simulated by using a simplified channel model. Finally, this thesis studies the interference of tow ship noise through beam-forming. The simulation describes acoustic characteristics of the tow ship noise well, and also provides

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11

Wang, Xuecheng, Xihai Jiang, and Bin Luo. "A method for suppressing strong near-field interference of large towed array." Journal of Physics: Conference Series 2990, no. 1 (2025): 012025. https://doi.org/10.1088/1742-6596/2990/1/012025.

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Abstract This paper addresses the challenge of diminished detection capabilities caused by strong near-field interference during the remote surveillance operations of large towed arrays. We introduce a method designed to suppress this near-field interference. By employing a spherical wave model to scan the near-field region, our approach obtains two-dimensional spatial spectrum estimations in terms of distance and azimuth, facilitating precise near-field localization. Utilizing the localization outcomes, we construct an orthogonal complementary projection space for the covariance matrix and pr

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Fan, Hailin, Wenxiang Nie, Shuai Yao, et al. "A high-order time-delay difference estimation method for signal enhancement in the distorted towed hydrophone array." Journal of the Acoustical Society of America 156, no. 3 (2024): 1996–2008. http://dx.doi.org/10.1121/10.0029021.

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In passive sonar systems, deviations from an ideal linear configuration can significantly impair the beamforming performance of towed hydrophone arrays. This paper presents a method aimed at improving the underwater acoustic signals in the presence of array distortion. The method is centered on a high-order time-delay difference estimation technique utilizing time-frequency autofocus. Initially, a detailed signal model is established that captures the distinctive characteristics of distorted arrays. Subsequently, an algorithm is introduced for high-order time-delay difference estimation to enh

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Barkley, Yvonne M., Eva-Marie Nosal, and Erin M. Oleson. "Model-based localization of deep-diving cetaceans using towed line array acoustic data." Journal of the Acoustical Society of America 150, no. 2 (2021): 1120–32. http://dx.doi.org/10.1121/10.0005847.

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14

Ellis, D. D. "Shallow water reverberation: normal-mode model predictions compared with bistatic towed-array measurements." IEEE Journal of Oceanic Engineering 18, no. 4 (1993): 474–82. http://dx.doi.org/10.1109/48.262297.

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15

Zhang, Yuhang, Jianbo Ju, and Siqing Wang. "Research on the performance of multi-base buoy arrays under the condition of on-called anti-submarine and warship-helicopter cooperation." MATEC Web of Conferences 232 (2018): 04033. http://dx.doi.org/10.1051/matecconf/201823204033.

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In order to improve the performance of traditional on-called Anti-submarine, the method of combining the towed sonar and helicopter deployment with traditional buoy arrays for multi-base searching is proposed. Combining the acoustics principle and the actual movement characteristics of warships and helicopters, model of naval movement and multi-base passive circular buoy arrays,square buoy arrays, and triangle buoy arrays deployed by a helicopter were established. The Monte Carlo method was used to simulate and analyse the effect of the initial distance from the call point, the initial positio

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Relano, R.-Jay S., Kate G. Francisco, Ronnie S. Concepcion II, et al. "SpeedX: Smart Speed Controller Model of Towed Subterranean Imaging System for Resistivity Data Distortion Reduction Using Computational Intelligence." Journal of Advanced Computational Intelligence and Intelligent Informatics 27, no. 1 (2023): 3–11. http://dx.doi.org/10.20965/jaciii.2023.p0003.

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Land surveying has been one of the core operations in performing underground imaging. It is known that dynamic and continuous resistivity readings were employed through this technique using the array of capacitive electrodes being towed with a light vehicle. However, the main challenge in doing subsurface surveying is the change in speed of the system when there are inevitable obstacles and sloping road surfaces. To address it, this study will develop prediction models using different computational intelligence such as multigene symbolic regression genetic programming (MSRGP), regression-based

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17

Sonnemann, Tim, Jan Dettmer, Charles W. Holland, and Stan Dosso. "Trans-dimensional Inversion in two spatial dimensions for geoacoustic parameters." Journal of the Acoustical Society of America 152, no. 4 (2022): A185. http://dx.doi.org/10.1121/10.0015972.

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We test a series of model parametrizations to invert a two-dimensional (2-D) seabed transect going from simple fixed-dimensional to more complex trans-dimensional configurations. Inverting spherical-wave reflection coefficient datasets independently as one-dimensional layered models for a 2-D section is less efficient than applying a more parsimonious 2-D parametrization while also carrying out full uncertainty quantification. We approach the problem by proposing different fixed and dynamically inferred parametrization schemes, and discuss implementation, computational cost and resulting accur

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18

Díaz Charris, Vladimir, and Juan A. Contreras Montes. "Design and development of route planner for Unmanned Surface Vehicles." Ciencia y tecnología de buques 11, no. 21 (2017): 89. http://dx.doi.org/10.25043/19098642.151.

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This paper describes the development of a route planner for Unmanned Surface Vehicles (USVs) focused on the study of an operational scenario for a specific mission – Anti-Submarine Warfare (ASW). Through the design and implementation of a simulation model, the effect of the different factors that particularly influence ASW is analyzed, such as search pattern, speed and sensor type; dipping sonar or towed array sonar (TAS). By obtaining a measurement of effectiveness, the USV’s response in the deployment of this type of mission can be defined using time to detect the threat in a search area, as

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19

Han, Songtong, Xiaoli Rong, Leixiang Bian, Mingyou Zhong, and Lining Zhang. "The Application of Magnetometers and Electromagnetic Induction Sensors in UXO Detection." E3S Web of Conferences 131 (2019): 01045. http://dx.doi.org/10.1051/e3sconf/201913101045.

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This paper introduces the physical model of unexploded ordnance (UXO) in the magnetization process and the formula derivation of the magnetic dipole model. The application of magnetometers and electromagnetic induction sensors in the detection of UXO is introduced. The magnetometers introduce the total field measurements technology of the CS optical-pump marine magnetometer and the MagSTAR (Magnetic Scalar Triangulation and Ranging) gradient detection technology. The electromagnetic induction sensors introduce the working theories and the popular product models of Geophex company and Geonics L

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Billings, Stephen, and Laurens Beran. "Optimizing electromagnetic sensors for unexploded ordnance detection." GEOPHYSICS 82, no. 3 (2017): EN25—EN31. http://dx.doi.org/10.1190/geo2016-0232.1.

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Time-domain electromagnetic (TEM) instruments are the predominant geophysical sensor for detection of buried unexploded ordnance (UXO). Detection surveys commonly use towed TEM sensor arrays to acquire a digital map for target detection. We use a dipolar model to predict a detection threshold for a UXO at a specified clearance depth, given an arbitrary sensor geometry. In general, the minimum target response is obtained for a horizontally oriented target. We find that for multistatic sensors, the minimum response can also depend on the azimuth of the target. By considering the statistics of th

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21

Schinault, Matthew E., Max Radermacher, Jesse Segel, and Purnima Ratilal. "Optimizing hydrophone-preamplifier systems: Theoretical design, computational analysis, and experimental validation for towed array applications." Journal of the Acoustical Society of America 155, no. 3_Supplement (2024): A349—A350. http://dx.doi.org/10.1121/10.0027792.

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Hydrophone response parameters greatly influence the design of pre-amplifier and analog to digital conversion (ADC) components. Here, we show a comprehensive methodology for the modeling of hydrophone response, focusing on the theoretical, computational, and experimental approach for low and high frequency SONAR applications. Theoretical calculation of hydrophone response based on electromechanical properties is compared with Finite Element Analysis (FEA) and experimental measurement. An electrical equivalent hydrophone simulator Butterworth-Van Dyke (BVD) circuit is constructed based on admit

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22

Sonnemann, Tim, Jan Dettmer, Charles W. Holland, and Stan Dosso. "High-resolution transdimensional geoacoustic inversion using autonomous underwater vehicle data." Journal of the Acoustical Society of America 152, no. 4 (2022): A146. http://dx.doi.org/10.1121/10.0015845.

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We invert reflection coefficient measurements of muddy sediment layers along a 12-km seabed transect on the Malta Plateau in the Mediterranean Sea using 1711 source transmissions recorded on a 32-element linear hydrophone array with both source and array towed by an autonomous underwater vehicle. Trans-dimensional Bayesian inference using reversible jump Markov chain Monte Carlo sampling is applied to obtain posterior probability densities of the number of homogeneous sediment layers, their depths, and their geoacoustic parameters. The forward sediment acoustics model is based on the grain-she

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23

Ellis, Dale D., Jie Yang, John R. Preston, and Sean Pecknold. "A Normal Mode Reverberation and Target Echo Model to Interpret Towed Array Data in the Target and Reverberation Experiments." IEEE Journal of Oceanic Engineering 42, no. 2 (2017): 344–61. http://dx.doi.org/10.1109/joe.2017.2674106.

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24

Zha, Zijie, Xi Yan, Xiaobin Ping, Shilong Wang, and Delin Wang. "Deblurring of Beamformed Images in the Ocean Acoustic Waveguide Using Deep Learning-Based Deconvolution." Remote Sensing 16, no. 13 (2024): 2411. http://dx.doi.org/10.3390/rs16132411.

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A horizontal towed linear coherent hydrophone array is often employed to estimate the spatial intensity distribution of incident plane waves scattered from the geological and biological features in an ocean acoustic waveguide using conventional beamforming. However, due to the physical limitations of the array aperture, the spatial resolution after conventional beamforming is often limited by the fat main lobe and the high sidelobes. Here, we propose a method originated from computer vision deblurring based on deep learning to enhance the spatial resolution of beamformed images. The effect of

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Schinault, Matthew E., and Purnima Ratilal. "An end-capped lead zirconate titanate broadband hydrophone theoretical calculation and electroacoustic measurement for towed array applications." Journal of the Acoustical Society of America 152, no. 4 (2022): A296. http://dx.doi.org/10.1121/10.0016333.

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Hydrophone transducers for towed array applications require low self-noise, small form factor and a linear frequency response below 50 kHz for general purpose long-range ocean sensing. The design specification for this hydrophone application has several aspects including acoustic sensitivity, frequency response, dissipation factor, and physical size. A comprehensive noise model informs filter design for pre-amplifiers after the piezoelectric element. Theoretical calculation of pressure to voltage conversion is made here by estimating the Free-Field Voltage Sensitivity (FFVS) using methods from

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Kamal, Ashley, and Madeline Miller. "Shallow water acoustic spatial coherence." Journal of the Acoustical Society of America 151, no. 4 (2022): A138. http://dx.doi.org/10.1121/10.0010905.

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The understanding and ability to predict acoustic spatial coherence in dynamic ocean environments is limited, as it depends on many small scale physical processes. Development and validation of theoretical models requires the assessment of coherence in diverse ocean conditions. We compute spatial coherence measures for the SwellEx-96 experiment and evaluate the functional dependence of coherence on frequency in a shallow water environment. The acoustic signals are low-frequency multi-tones (50–400 Hz) transmitted from a ship-towed source and received on horizontal bottom-mounted arrays deploye

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Gagnon, R. "Physical Model Experiments to Assess the Hydrodynamic Interaction Between Floating Glacial Ice Masses and a Transiting Tanker." Journal of Offshore Mechanics and Arctic Engineering 126, no. 4 (2004): 297–309. http://dx.doi.org/10.1115/1.1835986.

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An array of nine fabricated models comprised of three different shapes, with three model sizes for each shape, has been utilized in tow tank tests to investigate the hydrodynamic interaction between glacial ice masses and a transiting tanker. A generic model tanker was towed past free-floating ice mass models at various speeds and proximities. The ice masses were either spherical, pyramidal or cylindrical in shape. The influence of waves of various periods and wave heights was also investigated. Sway and surge of the ice masses in response to the tanker passage were measured as the primary ind

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Zhao, Meng, Wenbo Wang, Qunyan Ren, Haiyan Ni, Xu Xiao, and Li Ma. "Modified you-only-look-once model for joint source detection and azimuth estimation in a multi-interfering underwater acoustic environment." Journal of the Acoustical Society of America 153, no. 4 (2023): 2393. http://dx.doi.org/10.1121/10.0017828.

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The you-only-look-once (YOLO) model identifies objects in complex images by framing detection as a regression problem with spatially separated boundaries and class probabilities. Object detection from complex images is somewhat similar to underwater source detection from acoustic data, e.g., time-frequency distributions. Herein, YOLO is modified for joint source detection and azimuth estimation in a multi-interfering underwater acoustic environment. The modified you-only-look-once (M-YOLO) input is a frequency-beam domain (FBD) sample containing the target and multi-interfering spectra at diff

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Edwards, R. N. "Two‐dimensional modeling of a towed in‐line electric dipole‐dipole sea‐floor electromagnetic system: The optimum time delay or frequency for target resolution." GEOPHYSICS 53, no. 6 (1988): 846–53. http://dx.doi.org/10.1190/1.1442519.

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Towed in‐line transient electric dipole‐dipole systems are being used to map the electrical conductivity of the sea floor. The characteristic response of a double half‐space model representing conductive seawater and less conductive crustal material to a dipole‐dipole system located at the interface consists of two distinct parts. As time in the transient measurements progresses, two changes in field strength are observed. The first change is caused by the diffusion of the electromagnetic field through the resistive sea floor; the second is caused by diffusion through the seawater. The charact

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30

Swidinsky, Andrei, and R. Nigel Edwards. "Joint inversion of navigation and resistivity using a fixed transmitter and a towed receiver array: a transient marine CSEM model study." Geophysical Journal International 186, no. 3 (2011): 987–96. http://dx.doi.org/10.1111/j.1365-246x.2011.05104.x.

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Weglein, Arthur B., and Bruce G. Secrest. "Wavelet estimation for a multidimensional acoustic or elastic earth." GEOPHYSICS 55, no. 7 (1990): 902–13. http://dx.doi.org/10.1190/1.1442905.

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A new and general wave theoretical wavelet estimation method is derived. Knowing the seismic wavelet is important both for processing seismic data and for modeling the seismic response. To obtain the wavelet, both statistical (e.g., Wiener‐Levinson) and deterministic (matching surface seismic to well‐log data) methods are generally used. In the marine case, a far‐field signature is often obtained with a deep‐towed hydrophone. The statistical methods do not allow obtaining the phase of the wavelet, whereas the deterministic method obviously requires data from a well. The deep‐towed hydrophone r

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Riss, Joëlle, Juan Luis Fernández-Martínez, Colette Sirieix, Ouassima Harmouzi, Antoine Marache, and Ali Essahlaoui. "A methodology for converting traditional vertical electrical soundings into 2D resistivity models: Application to the Saïss basin, Morocco." GEOPHYSICS 76, no. 6 (2011): B225—B236. http://dx.doi.org/10.1190/geo2010-0080.1.

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We demonstrated a simple methodology for the reinterpretation of sets of electrical vertical soundings and the production of 2D resistivity models. The method is applied to the northern central part of the subsiding Saïss basin (Morocco) where a series of vertical electrical soundings (VES) were acquired in 1982 and 1984, using the Schlumberger array with current electrodes semispacings between 3 and 3000 m. We describe a methodology used to estimate and sample apparent resistivities collected from traditional single soundings acquired by using a Schlumberger configuration. We then construct a

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Zhu, Chuanqi, Shiliang Fang, Qisong Wu, Liang An, Xinwei Luo, and Hongli Cao. "A Time-Frequency Joint Time-Delay Difference Estimation Method for Signal Enhancement in the Distorted towed Hydrophone Array." Remote Sensing 13, no. 22 (2021): 4586. http://dx.doi.org/10.3390/rs13224586.

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To acquire the enhanced underwater ship-radiated noise signal in the presence of array shape distortion in a passive sonar system, the phase difference of the line-spectrum component in ship-radiated noise is often exploited to estimate the time-delay difference for the beamforming-based signal enhancement. However, the time-delay difference estimation performance drastically degrades with decreases of the signal-to-noise ratio (SNR) of the line-spectrum component. Meanwhile, although the time-delay difference estimation performance of the high-frequency line-spectrum components is generally s

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Hefner, Brian T., Jie Yang, and Dajun Tang. "Environmentally constrained modeling of mid-frequency transmission loss and reverberation measured during the Target and Reverberation Experiment 2013." Journal of the Acoustical Society of America 151, no. 4 (2022): A138—A139. http://dx.doi.org/10.1121/10.0010908.

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The goal of the Target and Reverberation Experiment (TREX13) was to make contemporaneous measurements of mid-frequency (1.5–4 kHz) transmission loss and reverberation with extensive environmental measurements so detailed model/data comparison can be achieved and important environmental factors can be identified for different applications. APL-UW collaborated with ARL-Penn State, led by John R. Preston, to deploy the Five Octave Research Array (FORA) on a “clothesline” about 2.1 m above the seafloor. This fixed-source/receiver configuration helped eliminate uncertainties from the motion of a to

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Kukshtel, Natalie, Andone C. Lavery, and Ying-Tsong Lin. "Acoustic propagation through a biological deep scattering layer at the New England shelf break." Journal of the Acoustical Society of America 155, no. 3_Supplement (2024): A99. http://dx.doi.org/10.1121/10.0026941.

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The New England Shelf Break is a dynamic ocean environment with strong spatial variability due to complex physical processes and interactions with warm core rings originating from the Gulf Stream. An acoustic autonomous underwater vehicle (AUV) was deployed in the New England Shelf Break Acoustics (NESBA) experiment in May 2021 to investigate environmental variability and its effect on sound propagation. The AUV system was comprised of a modified REMUS 600 vehicle with a hull-mounted 3.5 kHz transducer, a downward-facing EK80 echosounder, and a towed linear hydrophone array. Shipboard EK80 dat

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Li, Nansong, Minghui Zhang, and Bo Gao. "Horizontal Correlation of Long-Range Bottom Reverberation in Shallow Sloping Seabed." Journal of Marine Science and Engineering 9, no. 4 (2021): 414. http://dx.doi.org/10.3390/jmse9040414.

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The performance of active sonar detection systems is seriously affected by the reverberation at the bottom of the waveguide in shallow water. In order to improve the performance of active sonar detection, it is necessary to understand the horizontal correlation of shallow-water bottom reverberation in active towed-array processing technology. However, the current research on the spatial correlation of reverberation is mainly based on vertical correlation, little work has been done on the horizontal correlation characteristics of long-distance seabed reverberation, and there is no support from

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Jung, Youngcheol, and Keunhwa Lee. "Observation of the Relationship between Ocean Bathymetry and Acoustic Bearing-Time Record Patterns Acquired during a Reverberation Experiment in the Southwestern Continental Margin of the Ulleung Basin, Korea." Journal of Marine Science and Engineering 9, no. 11 (2021): 1259. http://dx.doi.org/10.3390/jmse9111259.

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We observed a distinct drop-off region in the bearing-time record of acoustic reverberation data acquired from the south-western continental margin of the Ulleung Basin, East Sea, in the summer of 2015. 3 kHz continuous waves with pulse lengths of 0.1, 0.3, and 1.0 s were used as source pulses, with an R/V Cheonghae vessel towing a variable depth source and a triplet towed array toward the deep sea from shallow water. The observed pattern changed as the R/V Cheonghae moved across the continental slope further into the sea. This pattern arises as a result of the downward-refracted beams in the

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Amundsen, Lasse, Ørjan Pedersen, Are Osen, Johan O. A. Robertsson, and Martin Landrø. "Broadband seismic over/under sources and their designature-deghosting." GEOPHYSICS 82, no. 5 (2017): P61—P73. http://dx.doi.org/10.1190/geo2016-0512.1.

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The source depth influences the frequency band of seismic data. Due to the source ghost effect, it is advantageous to deploy sources deep to enhance the low-frequency content of seismic data. But, for a given source volume, the bubble period decreases with the source depth, thereby degrading the low-frequency content. At the same time, deep sources reduce the seismic bandwidth. Deploying sources at shallower depths has the opposite effects. A shallow source provides improved high-frequency content at the cost of degraded low-frequency content due to the ghosting effect, whereas the bubble peri

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Yang, Fujin, Yuhuai Ni, Tao Hu, and Licheng Lu. "Accurate prediction of signal waveform in the convergence zone of the South China Sea based on frequency shift compensation ." Journal of the Acoustical Society of America 154, no. 4_supplement (2023): A357. http://dx.doi.org/10.1121/10.0023789.

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In a deep-sea environment in the South China Sea, a towed sound source is near the surface, and the acoustic signal is received by the vertical array of submersible buoys. The correlation values between the predicted and the measured signal waveform of the first two convergence zones (CZs) are poor, both below 0.5. The sea condition of the test area is good, the hydrological environment changes little in the horizontal direction. The analysis shows that when the underwater acoustic waveform is predicted, due to the relative motion of the transmitting and receiving elements, the channel dispers

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Lewis, B. T. R., and H. Jung. "Attenuation of refracted seismic waves in young oceanic crust." Bulletin of the Seismological Society of America 79, no. 4 (1989): 1070–88. http://dx.doi.org/10.1785/bssa0790041070.

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Abstract It is commonly observed in seismic refraction experiments over young oceanic crust that refracted energy is concentrated in the 10 to 15 Hz band, even though the source may have far greater bandwidth. We apply spectral ratio methods to data from a midwater hydrophone array towed 10 km from the Juan de Fuca ridge and confirm that the impulse response of the crust to refracted energy has a peak near 10 Hz. This peak appears to result from a combination of two factors that produce attenuation. One is related to the large velocity gradient in the upper crust caused by crack closure with i

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Hughes, Larry J. "Mapping contaminant-transport structures in karst bedrock with ground-penetrating radar." GEOPHYSICS 74, no. 6 (2009): B197—B208. http://dx.doi.org/10.1190/1.3223312.

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Ammonium perchlorate, a risk to human health, was used formerly to manufacture rocket fuel at the Naval Weapons Industrial Reserve Plant (NWIRP) McGregor, McLennon County, Texas. Perchlorate exists in several groundwater contaminant plumes, whose geometries were suspected to be influenced by transmissive bedrock structures. To identify these possible contaminant-transport pathways, a towed-array ground-penetrating radar (GPR) system was used to acquire 118 line-km of data across [Formula: see text] of the property. The shallow geology consists of bedrock limestone overlain by [Formula: see tex

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Keller, Ray, Lance Davidson, Anna Edlund, et al. "Mechanisms of convergence and extension by cell intercalation." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 355, no. 1399 (2000): 897–922. http://dx.doi.org/10.1098/rstb.2000.0626.

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The cells of many embryonic tissues actively narrow in one dimension (convergence) and lengthen in the perpendicular dimension (extension). Convergence and extension are ubiquitous and important tissue movements in metazoan morphogenesis. In vertebrates, the dorsal axial and paraxial mesodermal tissues, the notochordal and somitic mesoderm, converge and extend. In amphibians as well as a number of other organisms where these movements appear, they occur by mediolateral cell intercalation, the rearrangement of cells along the mediolateral axis to produce an array that is narrower in this axis a

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Gray, D. A., B. D. O. Anderson, and R. R. Bitmead. "Towed array shape estimation using Kalman filters-theoretical models." IEEE Journal of Oceanic Engineering 18, no. 4 (1993): 543–56. http://dx.doi.org/10.1109/48.262304.

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Wang, Fei, Ke Du, Jingjiang Sun, Fuyun Huang, and Zhenghui Xiong. "Shaking Table Array Tests of an Ultra-High-Voltage Cup-Type Transmission Tower-Line System." Shock and Vibration 2019 (December 11, 2019): 1–20. http://dx.doi.org/10.1155/2019/2350675.

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Ultra-high-voltage (UHV) cup-type transmission towers supported with long-span transmission lines are unavoidably subjected to the coupling action between the towers and the transmission lines. Therefore, investigating how tower-line coupling affects UHV cup-type transmission towers is important. In this study, three shaking table array tests of an UHV cup-type transmission tower-line system were carried out to investigate the dynamic characteristics of the coupling action between the towers and transmission lines based on the following four comparative models: a single-tower model, a single-t

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Ma, Lun, Pierre-Luc Delafin, Panagiotis Tsoutsanis, Antonis Antoniadis, and Takafumi Nishino. "Blade-Resolved CFD Simulations of a Periodic Array of NREL 5 MW Rotors with and without Towers." Wind 2, no. 1 (2022): 51–67. http://dx.doi.org/10.3390/wind2010004.

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A fully resolved (FR) NREL 5 MW turbine model is employed in two unsteady Reynolds-averaged Navier–Stokes (URANS) simulations (one with and one without the turbine tower) of a periodic atmospheric boundary layer (ABL) to study the performance of an infinitely large wind farm. The results show that the power reduction due to the tower drag is about 5% under the assumption that the driving force of the ABL is unchanged. Two additional simulations using an actuator disc (AD) model are also conducted. The AD and FR results show nearly identical tower-induced reductions of the wind speed above the

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Zhang, Ya Xin, Qi Gao, and Xiao Zi Xu. "The Strength Reliability Analysis at Connecting Region of Cylinder and Skirt of Coke Tower Based on Stochastic Finite Element." Key Engineering Materials 620 (August 2014): 431–36. http://dx.doi.org/10.4028/www.scientific.net/kem.620.431.

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In this paper, Based on the original operating parameters of the Coke tower which works in the PetroChina Dushanzi Petrochemical Corp, and the skirt - tower body support section as the research object, using stochastic finite element method and Monte Carlo method, 60 groups of pressure, temperature are extracted randomly as variables in the original operating parameters curve, the change of the distribution function of temperature and pressure are analysed and established, and 200 groups of random pressure, temperature variable array is produced based on this; The maximum stress in dangerous s

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Xue, Zhaoxuan, Xingang Zhang, Jian Hou, and Xi Liu. "Optimization Design of Feed Tower for High-frequency Band Multi-beam Antenna on Satellite." Journal of Physics: Conference Series 2383, no. 1 (2022): 012049. http://dx.doi.org/10.1088/1742-6596/2383/1/012049.

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Aiming at the layout of a certain feed array for multi-beam antenna on satellite, a feed tower design method based on 3D printing technology is proposed. This design method uses aluminum alloy 3D printing to form the main support structure under the premise of avoiding the installation holes and layout positions, and adopts the combination of the main structure of the honeycomb lattice and the local solid structure to reduce the structural quality. The mechanical analysis and optimization of the design model are carried out by combining the actual test data of the mechanical test plate and ANS

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Lu, Nan-You, Lance Manuel, Patrick Hawbecker, and Sukanta Basu. "A Simulation Study on Risks to Wind Turbine Arrays from Thunderstorm Downbursts in Different Atmospheric Stability Conditions." Energies 14, no. 17 (2021): 5407. http://dx.doi.org/10.3390/en14175407.

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Thunderstorm downbursts have been reported to cause damage or failure to wind turbine arrays. We extend a large-eddy simulation model used in previous work to generate downburst-related inflow fields with a view toward defining correlated wind fields that all turbines in an array would experience together during a downburst. We are also interested in establishing what role contrasting atmospheric stability conditions can play on the structural demands on the turbines. This interest is because the evening transition period, when thunderstorms are most common, is also when there is generally ack

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YIN Jingwei, YIN Jiarui, CAO Ran, HUANG Chunlong, and LI Li. "A target depth estimation method in shallow water based on matched normal mode intensity." Acta Physica Sinica 74, no. 14 (2025): 0. https://doi.org/10.7498/aps.74.20250419.

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A novel target depth estimation method based on normal mode intensity match is proposed for shallow water environment using horizontal array to overcome the performance degradation observed in conventional approaches under seabed parameters mismatch condition. First, horizontal wavenumbers and normal mode intensities are estimated through wavenumber domain beamforming. Second, modal function of normal mode inversion is performed by solving the modal function characteristic equation through finite difference method. Third, the match degree between inverted and estimated normal mode intensities

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Li, Xinyu, Xiangqian Zhu, Mingqi Sun, et al. "Surrogate model-based optimization of drogue dimensions and towing operations to straighten deep-towed nonuniform arrays." Ocean Engineering 299 (May 2024): 117321. http://dx.doi.org/10.1016/j.oceaneng.2024.117321.

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