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Broadband underwater target echo detection based on signal spectral irregularity feature

Journal of Southeast University(English Edition) 2018年第2期34卷 147-155页

作者： Chen Yunfei Li Sheng Jia Bing Wang Zhenshan Li Guijuan School of Naval Architecture Dalian University of TechnologyDalian 116024China Science and Technology on Underwater Test and Control Laboratory Dalian 116013China

For the detection of underwater target echo under strong interferences,the modulation feature of direct echo signal and reverberation spectrum are characterized by the signal spectral irregularity feature,and the relationship between signal spectral irregularity and target physical properties is theoretically formed.A novel method of broadband underwater target echo detection under reverberation based on the signal spectral irregularity characteristics is *** proposed method has the capability of discriminating between the direct target echo signal from *** results of complex underwater target broadband acoustic scattering show that the echo can be detected even with the signal to reverberation ratio(SRR)below-10 dB by the proposed method based on the spectral irregularity(SI)*** corresponding sea experimental results also show that echo can be detected when the SRR is below 0 *** effectiveness and correctness of the proposed method are verified both in simulated data and in real data in sea experiment.

关键词： echo reverberation signal spectral irregularity

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Mechanism and influence of removing algae with chlorine dioxide treatment for ship ballast water

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IOP Conference Series: Materials Science and Engineering 2019年第2期631卷

作者： Linan Jia Dawen Jiao Yin Yue Xiaotao Shi Lin Sun Science and Technology on Underwater Test and Control Laboratory Dalian China

This study aims at examining the performance of the ClO2 on treating ballast water of Dalian new port area foreign trade oil pool in the cases of different experimental parameters, and Cylindrospermopsis raciborskii (CR), Gymnodinium catenatum (GC) and Gymnodinium cf. mikimotoi (GCM) are used for this experiment. The results shows that under certain test condition, the removal rates are in proportion to the dosage of ClO2 and reaction time, and inversely proportion to pH value, humic acid and ammonia nitrogen content. Accordingly, on operating at the optimal dosage of ClO2 and parameters of experiment, this process is proven to be an effective technology to remove these three algae and organic compounds in ballast water. In ballast water, the removal ability of ClO2 for these three algae is less sensitive to pH value, humic acid and ammonia nitrogen content than to ClO2 dosage and reaction time. Removing GC, GCM and CR with ClO2 are attributed to the second order reaction. Investigating the performance of such process, could serve to develop management strategies that enable mitigating the impacts of harmful substance in ballast water and help improving and ensuring quality of ballast water.

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Design of marine environmental noise signal generation system based on MATLAB, LabVIEW and FPGA

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Journal of Physics: Conference Series 2019年第1期1303卷

作者： Feng Gao Chunxia Meng Key Laboratory for Underwater Test and Control Technology Dalian 116013 China

Marine environmental noise is a background interference field produced by various underwater sound sources. The characteristics of marine environment vary with time, place and frequency. In order to simulate the marine environmental noise signals with different time-frequency characteristics, a real-time generating system of marine environmental noise signals is designed based on MATLAB, LabVIEW and FPGA. According to the probability distribution of the measured frequency characteristics of marine environmental noise, the random signals with specific frequency response are calculated and generated in real time and continuously. The pool test results show that the signal generation system has the characteristics of stable real-time calculation and signal generation. Based on the marine environmental noise signal generation system designed in this paper, time-domain waveforms with specific spectrum characteristics are generated, which will provide technical support for the research of random signal processing algorithm under laboratory conditions and the performance analysis of underwater acoustic equipment under different marine background conditions.

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Analysis on ship through signature of shallow inshore based on single hydrophone

Analysis on ship through signature of shallow inshore based ...

引用

2017 International Conference on Computer technology, Electronics and Communication, ICCTEC 2017

作者： Liu, Yanqiong Sheng, Xueli Xia, Chunyan Zhu, Shicai Zhang, Yu Chen, Guangfu Qin, Tongji Li, Li Luo, Fangfang Dalian Scientific Test and Control Technology Institute Dalian China Science and Technology on Underwater Acoustic Laboratory Harbin Engineering University Harbin China

ISBN: (纸本)9781538657843

For detection of shallow water channel, it needs to study the target characteristics in shallow water. As an important feature of the ship, ship through signature is simulated by the model of three highlights. In this model, this paper analyzes the effect of the source size and the working frequency band on the through signature curve. And it gets the through signature curve in shallow water and the relation between source size, speed and through signature by analysis of measured data, which effectively verifies the correctness of the simulation model. © 2017 IEEE.

关键词： Ships

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A research on blind area of random layout units for localization

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Journal of Physics: Conference Series 2019年第1期1303卷

作者： Zhizhuan Wang Ling Li Guijuan Li Yang Wang Science and Technology on Underwater test and Control Laboratory Binhai Street 16 Zhongshan Section Dalian city 116013 China

Acquisition distance information of the underwater target is very important to evaluate the target noise level, so it is necessary to do some research on the passive localization method for the underwater target. In this paper, the multi-hydrophone units model is used to passively achieve target localization information in the underwater environment; the accurate DOA estimation and ranging calculation method are presented. The localization blind area problem with different units models is discussed. The blind area problem caused by traditional passive localization model (three units) is solved by the method with four random units, which can locate the underwater unpredictable target in arbitrary direction.

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Modulation feature of underwater target broadband echo spectrum 7

Modulation feature of underwater target broadband echo spect...

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7th IEEE International Conference on Signal Processing, Communications and Computing, ICSPCC 2017

作者： Fei, Chen-Yun Li-Sheng Yan, Xia-Chun Jia-Bing Juan, Li-Gui School of Naval Architecture Dalian University of Technology Dalian China Science and Technology on Underwater Test and Control Laboratory Dalian China

ISBN: (纸本)9781538631409

Characteristics of elastic scattering wave depend on target elastic properties, the extraction of elastic wave characteristics is always difficult in underwater target detection by active sonar. Based on the modulation characteristics of broadband echo spectrum produced by target geometry scattering and elastic scattering, the modulation feature of echo spectrum was proposed and studied, expressing how underwater target properties effect on scattering wave spectrum. A sea testing of scaled benchmark and rock broadband acoustic scattering were conducted to verify the theoretical predication, which showed that targets of different properties could be well classified by the modulation feature of echo spectrum. © 2017 IEEE.

关键词： Modulation

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Numerical simulation of underwater acoustical field with directional sources based on the normal modes model

Numerical simulation of underwater acoustical field with dir...

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2017 International Conference on Electronic Information technology and Computer Engineering (EITCE 2017)

作者： Wang Jihui Wang Zhenshan Jia Bing Science and Technology on Underwater Test and Control Laboratory

In this paper, beamforming and normal modes method are combined to calculate the underwater acoustical field. Firstly, beamforming technology is used to form directional sources by controlling the phase and relative amplitude. Secondly, considering the ocean speed, surface and bottom boundary, the point source sound field is calculated based on the normal modes model. Then underwater acoustical field with directional sources is achieved by adding all point source field. Taken the 11 elements vertical linear array as an example, the special directional source is formed by chebyshev amplitude weighting, and then underwater acoustical field is calculated in the Munk profile of different grazing angles. The results indicate that beam grazing angle is very essential to its sound field, and changing the grazing angle can enhance the sound intensity of the shadow zone correspondingly.

关键词： Numerical simulation of underwater acoustical field with directional sources based on the normal modes model

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High selectivity reconfigurable filters with controlled channel bandwidth

High selectivity reconfigurable filters with controlled chan...

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IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP)

作者： S. F. Peik J. Jiang R. R. Mansour Science and Technology on Underwater Test and Control Laboratory Dalian China

In this paper, we present the design of a novel class of reconfigurable filters allowing a control of bandwidth and maintaining a high Q in all configured states. The concept can be applied to any type of filters including planar, waveguide as well as FBAR filters. The proposed filters have the potential to replace large numbers of fixed filters by a single tunable design. The key idea is to combine high-Q un-tuned resonators with a set of tunable resonators. The selected bands can be controlled by proper placement of fixed transmission zeros generated by the high-Q resonators. The combination allows a highly selective filter response with flat pass-band for all states. Measurements on a planar microstrip filter verify the concept.

关键词： Resonators Tuning Microwave filters Microwave communication Bandwidth Filtering theory

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Numerical analysis on target strength of the air filled cylindrical elastic shell

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Journal of Physics: Conference Series 2018年第3期1087卷 032034-032034页

作者： Wang, Jihui Li, Guijuan Jia, Bing Wang, Zhenshan Wang, Rui Science and Technology on Underwater Test and Control Laboratory Dalian China

Aimed at simulating the air filled finite cylindrical shell target strength, the numerical calculation method of scattering form function and target strength is given in this paper using the theory of Stanton T K. Cylindrical shells of different material properties, thickness, length are calculated, and the results indicate that factor of the material property and dimension is very important. Compared with other kinds of material properties, the gum rubber cylindrical shell has much more greater target strength for low frequency. Factors of radius and thickness have big effect to its fundamental resonance and the choice should be made in accordance with the actual needs. The numerical study provides theoretical basis and design reference for engineering application.

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The Study of Ocean Ambient Noise Reconstruction in Low and Medium Frequency Bands

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IOP Conference Series: Materials Science and Engineering 2018年第1期428卷

作者： Zhang Liang Wen Fengdan Meng Chunxia Han Jing Science and Technology on Underwater Test and Control Laboratory Dalian 116013 China

Ocean ambient noise is the general background of the sea, the sources of which is highly variable, the generated noise signal is random, it changes with time and space. It is usually considered that ocean ambient noise is a special random process with certain power spectrum, so the broadband stationary random process can be used for fitting the continuous spectral noise. This paper carried out statistical analysis on sample data obtained by continuous observation in one day, and then the statistic characteristics of ambient noise frequency spectrum in low and medium frequency bands can be calculated. Generating filter with specific frequency response based on the probability density function of sound pressure level in each frequency randomly, and ocean ambient noise is reconstructed effectively by Gaussian white noise passing the filter above. The simulation results have important implication for low and medium frequency underwater acoustic signal analysis in lab conditions, and it is helpful to test the performance of platform in the oceanic background.

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