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2020 International Conference on Electronics, Communications and Information technology, CECIT 2020

作者： Wang, Zhizhuan Zhang, Mingwei Li, Ling Li, Guijuan Chen, Yunfei Zhang, Xuegang Science and Technology on Underwater Test and Control Laboratory Dalian China

Buoys are generally difficult to anchor in Deep-sea environment, at the same, due to the influence of long-term in the ocean environment, the location relationship between each other buoys will change, which may cause the traditional predicted method of buoy system trapped in losing efficacy. This paper researched on the problem of the buoy baseline length vary positioning method applicability, on the basis of this study, focused on the theoretical analysis and simulation of applicability to different positioning method. Following this, a realtime positioning method based on vector buoys system in deep sea is presented. Covered the applicability shortage of traditional underwater acoustic passive positioning, used multiple vector buoys to locate the target jointly, and provide a theory basis for real-time positioning function of vector buoys in engineering. The simulation results show that this method is feasible and effective. © Published under licence by IOP Publishing Ltd.

关键词： Buoys

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Experimental Analysis of Statistical Property of Low Frequency Reverberation Envelope in Shallow Water

Experimental Analysis of Statistical Property of Low Frequen...

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2021 OES China Ocean Acoustics, COA 2021

作者： Cao, Feng Zhang, Xuegang Han, Jing Lv, Shuai Dalian Scientific Test and Control Technology Institute Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

Reverberation is the main background interference of active detection and identification, which is produced with active signal emission. It is traditionally assumed as a combination signal of a large amount of random scatters at the receiving hydrophone which leads to a Gaussian-distributed time-domain signal and a Rayleigh-distributed envelope following the central limit theorem. However, with the advent of high-resolution active sonar systems, the target-like scatter signals namely clutter arising from fluctuation or variety in seafloor or hydrographic would produce the non-Rayleigh reverberation with longer tail and it is a main factor restricting the active sonar long-range detection. Aiming at this phenomenon, the Rayleigh distribution model and two typical non-Rayleigh statistical models-the Weibull distribution and the K distribution model are studied using the low-frequency reverberation test data (signal center frequency at 420Hz) obtained from a typical shallow-water environment in the northern South China Sea. Based on the measured multi-sample reverberation data, the probability density distributions of different signal forms reverberation are calculated respectively. The parameters of different models are estimated by the method of moments (MOM) to perform the theory simulation and curve fitting, and then the correlation between data processing and model simulation results are calculated. Comparative analysis based on the experiments shows that the pulse length of transmitting signal has an important effect on the statistical characteristics of the reverberation in shallow water, which is reflected in the fact that the envelope distribution of short pulse-width reverberation presents stronger non-Rayleigh properties compared with long pulse-width reverberation. In addition, the long-range reverberation present stronger non-Rayleigh properties fitting with the non-Rayleigh models well relative to the short-range reverberation. The effect of frequency for

关键词： Reverberation

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Influences and Modification of Random Errors in Amplitude and Phase on the Fidelity of Vessel Radiated Noise Power Spectrum with Array

Influences and Modification of Random Errors in Amplitude an...

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2021 OES China Ocean Acoustics, COA 2021

作者： Yang, Wang Yan-Sen, Liu Gui-Juan, Li Dalian Scientific Test and Control Technology Institute Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

In the acquisition of vessel radiated noise characteristics based on acoustic array, element failure or acoustic propagation or other reasons will cause the random errors in amplitude and phase of each channel signal, and lead to vessel radiated noise power spectrum acquired by beam-forming. In order to modify this error, based on mathematical model, the difference between mean power spectrum of all channel signals and power spectrum of beam-forming with random errors in amplitude and phase was analyzed, and a correction method for power spectrum amplitude was established. The simulation results show that the effect of errors in phase is much greater than the errors in amplitude, and the correction method in this paper can effectively reduce the beam-forming power spectrum amplitude error. And the analysis results of measured data show that, taking the mean power spectrum of all channel signals as the reference, the error before correction was 3dB~5dB, and the corrected error was 1dB~3dB, meeting the error range requirements. © 2021 IEEE.

关键词： Random errors

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A Discrimination Method between Surface and Submerged Targets based on Frequency Diversity Wavenumber Domain Features

A Discrimination Method between Surface and Submerged Target...

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2021 OES China Ocean Acoustics, COA 2021

作者： Li, Peng Dalian Scientific Test and Control Technology Institute Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

The discrimination between surface and submerged targets is one of the research focuses of passive sonar target recognition. In this paper, a discrimination method based on frequency diversity in wavenumber domain is proposed. The energy distribution in frequency-wavenumber domain is extracted by horizontal array modal beamforming method, and the wavenumber domain information of each frequency point is coherently superimposed to obtain the frequency diversity wavenumber domain eigenvalue. According to the prior knowledge of environment and the normal mode acoustic field simulation method, the decision threshold of discrimination can be generated. Based on the comparison between the eigenvalues of frequency diversity wavenumber domain and the decision threshold, the surface and submerged targets resolution of passive horizontal array is obtained. Simulation results show that the proposed method can effectively extract the frequency diversity wavenumber characteristics of target radiated noise in 96m and 192m horizontal array aperture, which can be used for engineering discrimination of surface and submerged targets. © 2021 IEEE.

关键词： Eigenvalues and eigenfunctions

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Experimental and Simulation Research on Flow Noise of underwater High Speed Vehicles

Experimental and Simulation Research on Flow Noise of Underw...

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2021 OES China Ocean Acoustics, COA 2021

作者： Wang, Youzhi Jia, Lianhui Guo, Xinyu Dalian Scientific Test and Control Technology Institute Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781728181905

In this paper, the mechanism and characteristics of underwater high-speed vehicle flow noise are studied by experimental and simulation methods. The experiment was carried out in a gravity-type low-noise water tunnel of Harbin Engineering University. The radiation noise of the model under multiple incoming flow velocities was measured. At the same time, combined with the PIV particle tracing technology, the sound position and mechanism of underwater targets were further explored. Then establish the same model through CATIA and use ANSYS software to establish the flow field and sound field calculation models respectively, and simulate the flow noise of the model at different flow speeds. Finally, the experimental data and the simulation data are compared and analyzed. The results show the flow noise of the target increases with the increase of the flow velocity, and the turbulent velocity and pulsating pressure at the head of the model are higher, followed by the tail, and the convective noise in the middle section contributes less. © 2021 IEEE.

关键词： Flow velocity

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Impact of Evaporation Duct on Electromagnetic Wave Propagation During a Typhoon

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Journal of Ocean University of China 2022年第5期21卷 1069-1083页

作者： WANG Shuwen YANG Kunde SHI Yang YANG Fan ZHANG Hao School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Ocean Acoustics and Sensing Northwestern Polytechnical UniversityMinistry of Industry and Information TechnologyXi’an 710072China National Key Laboratory of Underwater Information Processing and Control Xi’an 710072China

The evaporation duct,a result of evaporation from the ocean,is a region above the sea surface in which radio waves are refracted *** duct has strong effects on microwave *** cause huge anomalies in marine meteorological parameters that influence the evaporation duct distribution and structure,which in turn affects the propagation of electromagnetic(EM)***,EM wave propagation under the typhoon process has seldom been ***,taking Typhoon Phanfone(201929)as an example,this study uses a dataset from the European Centre for Medium-Range Weather Forecasts,combined with the Naval Atmospheric Vertical Surface Layer Model and the parabolic equation model,to study the evaporation duct’s impact on EM wave propagation during a *** spatial and temporal path loss distributions reveal that large amounts of EM wave energy are emitted from the evaporation duct when the EM wave passes through a typhoon *** average,a typhoon eye causes an approximately 20 dB increase in path loss for EM wave propagation at low antenna ***,the effects of a typhoon eye on EM wave propagation at different signal frequencies and antenna heights are *** results show that a typhoon has a larger impact on EM wave propagation with low signal frequency and high antenna height.

关键词： evaporation duct typhoon ECMWF wave glider electromagnetic wave propagation

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Full-Space Beam Scanning Antenna Based on Spoof Surface Plasmon Polaritons

Full-Space Beam Scanning Antenna Based on Spoof Surface Plas...

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2023 International Applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Wu, Zhicheng Kong, Xianglin Wang, Jun Xu, Ruofeng Zhao, Lei Xu, Yinfang School of Information and Control Engineering China University of Mining and Technology Xuzhou China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (纸本)9781733509657

In this paper, a full-space beam scanning antenna based on spoof surface plasmon polaritons (SSPPs) is proposed. The proposed antenna is composed of a SSPPs loaded by the varactor diodes and periodic metallic patches. The periodic patches can transform the slow waves from SSPPs into fast waves, and the cutoff frequency can be reconfigured by changing the capacitance of the varactor diode, which will make the radiation angle of the beam change within a fixed frequency. Simulation results show that the radiation angle ranges from -90° to 90° at 9 GHz. © 2023 Applied Computational Electromagnetics Society (ACES).

关键词： Scanning antennas

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Adaptive cubature Kalman filter with the estimation of correlation between multiplicative noise and additive measurement noise

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Chinese Journal of Aeronautics 2022年第5期35卷 40-52页

作者： Quanbo GE Zhongcheng MA Jinglan LI Qinmin YANG Zhenyu LU Hong LI School of Electronics and Information Engineering Tongji UniversityShanghai 201804China Institute of Systems Science and Control Engineering School of AutomationHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Industrial Control Technology and the College of Control Science and EngineeringZhejiang UniversityHangzhou 310027China Jiangsu Key Laboratory of Meteorological Observation and Information Processing Nanjing University of Information Science and TechnologyNanjing 210044China Chinese Flight Test Establishment Xi’an 710089China

Mobile robots are often subject to multiplicative noise in the target tracking tasks,where the multiplicative measurement noise is correlated with additive measurement *** this paper,first,a correlation multiplicative measurement noise model is *** is able to more accurately represent the measurement error caused by the distance sensor dependence ***,the estimated performance mismatch problem of Cubature Kalman Filter(CKF)under multiplicative noise is *** improved Gaussian filter algorithm is introduced to help obtain the CKF algorithm with correlated multiplicative *** practice,the model parameters are unknown or inaccurate,especially the correlation of noise is difficult to obtain,which can lead to a decrease in filtering accuracy or even *** address this,an adaptive CKF algorithm is further provided to achieve reliable state estimation for the unknown noise correlation coefficient and thus the application of the CKF algorithm is ***,the estimated performance is analyzed theoretically,and the simulation study is conducted to validate the effectiveness of the proposed algorithm.

关键词： Adaptive CKF Correlated noise Estimation accuracy Multiplicative noise Performance analysis Target tracking

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Construction of Acoustic Dipole and Its Performance Verification test in Shallow Water

Construction of Acoustic Dipole and Its Performance Verifica...

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2021 OES China Ocean Acoustics, COA 2021

作者： Chunxia, Meng Xiaoyuan, Li Zhongcheng, Ma Feng, Cao Hang, Su Science and Technology on Underwater Test and Control Laboratory DaLian China Dalian Scientific Test and Control Technology Insititute DaLian China

ISBN: (纸本)9781728181905

The complex underwater noise field is formed in the process of the ship's constant volume sound source sailing. Due to the large number of machinery and equipment on the ship, and the navigation state of the ship on the sea is easy to change, these factors make it difficult to obtain the low-frequency radiated noise characteristics of the ship in a stable state. Therefore, it is an effective way to understand and master the characteristics of low-frequency underwater radiated noise field by using directional sound source in controllable state. Dipole transducer is a typical directional sound source with horizontal or vertical octagonal directivity, which is widely used in seismic and logging research. However, few dipole transducers are used in underwater acoustic research. The reason is: the directional emission of underwater acoustic low-frequency transducer is a big problem in the current transducer design. The directional emission technology of low-frequency dipole transducer is related to the distance / wavelength of the radiation surface. Because the position relationship of the radiation surface is fixed, it can only form the ideal directivity at a specific frequency. This brings great inconvenience to the application of underwater acoustic low- frequency dipole transducer. Firstly, the mathematical model of sound field radiated by acoustic dipole is established;then, the common non-directional low-frequency sound source is used to construct an acoustic dipole source. By adjusting the distance between two low-frequency sound sources, low-frequency dipole signals with different frequencies can be emitted. The lake test results show that the maximum difference of horizontal directivity of dipole source is less than 0.5dB and the depth of concave point is more than 21dB;finally, the test scheme in shallow water is designed, and the low-frequency narrow-band signals of 63Hz and 80Hz are emitted by the acoustic dipole source in uniform towing state, and the receiv

关键词： underwater acoustics

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Coupled analysis of Braceless semi-submersible offshore wind turbine under different water depths 32nd

Coupled analysis of Braceless semi-submersible offshore wind...

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32nd International Ocean and Polar Engineering Conference, ISOPE 2022

作者： Zhou, Zhimin Wang, Xianzhi Zhou, Xiangbo Qiao, Dongsheng Yan, Jun Ning, Dezhi Science and Technology on Underwater Test and Control Laboratory the 760th Research Institute of China Shipbuilding Industry Corporation Dalian China State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian China

ISBN: (纸本)9781880653814

Braceless semi-submersible floating offshore wind turbine (FOWT) is subjected to environmental loads during its service, and the different combinations of wind, wave, and current environmental loads have different contributions to the motion responses of the offshore wind turbine platform. Under the different water depth of 100m, 150m, 200m, the time domain motion response calculation model of floating wind turbine platform was established, and the corresponding time-domain motion of wind turbine platform with six degrees of freedom and the mooring line tension were analyzed. The results show that the maximum motion response and mooring line tension are all in line with the engineering requirements. The results of this study provide reference for further research on the design of mooring system. © 2022 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Semisubmersibles

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