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IEEE International Conference on Power, Intelligent Computing and Systems (ICPICS)

作者： Cao Lin Shi Min Science and Technology on Underwater Test and Control Laboratory Dalian China Navy Academic of Armor Beijing China

ISBN: (纸本)9781728137216

In view of how to effectively detect a complete pulse period and the echo signal without triggering information and the fixed pulse cycle, this paper proposed a real-time detection algorithm of echo signal and developed a detection software of echo signal on the platform of Visual C++. First of all, the relative frequency domain energy detection algorithm was adopted to detect a pulse cycle through the adaptive threshold. Then, the echo signal was detected by the copy correlation algorithm. At last, the results were visualized in real time for the users. The experiment of the algorithm showed that the software can detect the complete pulse cycle and echo signal, and the performance of the system is quite stable.

关键词： Real-time systems Detection algorithms Correlation Frequency-domain analysis Software Message systems Image edge detection

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Envelope Phase Shift Feature Extraction of underwater Target Echo

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Journal of Physics: Conference Series 2020年第1期1438卷

作者： Yong, Jintao Chen, Yunfei Zhang, Yang Jia, Bing Li, Guijuan Science and Technology on Underwater Test and Control Laboratory Dalian China

Aiming at the problem of target classification with different physical property parameters, the phase characteristics of echo envelope associated with different physical property parameters are studied, and the feature extraction method of the phase shift characteristics of the target echo envelope is established. The extraction method and the feature resolution performance of the phase shift characteristics of echo envelope are verified by the water-tank test of cylindrical targets with different materials and finite length. The experimental results of the underwater cylindrical target echo show that the feature of target echo envelope phase shift has significant difference with the change of target material, structure and radial scale. The phase shift feature of underwater target echo envelope has good performance for targets with different physical property parameters.

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Echo signal simulation system

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Journal of Physics: Conference Series 2020年第1期1633卷

作者： Feng Gao Yang Zhang Zhenshan Wang Guijuan Li Science and Technology on Underwater Test and Control Laboratory Dalian China

In order to meet the demand of realistic simulation for complex target echo signal in water, the indirect method of frequency domain is employed to simulate the target echo signal in this paper. The plate element method is first used to forecast complex target echo characteristics in typical water. After generating frequency response function data, the data is imported into the echo signal simulation system. The system adopts FPGA real-time signal processing system based on PXIe bus. It receives hydrophone output signal by A/D sampling, extracts the incident acoustic signal and makes frequency domain transformation. After multiplying the transformed signal and frequency response function, scattering echo spectrum is obtained. And then the time domain transformation is made to get the time series of the echo signal. The series is loaded into the transmitting transducer by the power amplifier and the echo signal is simulated. The system has the high fidelity of the model, stable and reliable hardware system, and software system for easy operation.

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The effect of ocean turbulence on acoustic propagation in shallow water

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IOP Conference Series: Earth and Environmental Science 2020年第1期580卷

作者： Jing Han Xuegang Zhang Zhongpeng Wu Feng Cao Science and Technology on Underwater Test and Control Laboratory Dalian China 116013

This work devoted to research the temperature and salinity distribution in ocean turbulence. The sound velocity when ocean turbulence presented was calculated by the function relation between temperature, salinity, depth and sound velocity. The sound transmission loss was calculated when the ocean turbulence was presented or not and compared them. The sound field fluctuation resulted by ocean turbulence was analyzed. It was very significant to comprehend the mechanism and variation rule of ocean turbulence. Thus it was further study the effect of ocean turbulence on acoustic propagation. As an example, there was thermocline in the ocean water. The sound transmission loss was calculated when presented ocean turbulence or not. It analyzed the effect of ocean turbulence on acoustic propagation. The sound field fluctuation caused by ocean turbulence could reach 8dB.

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Numerical Analysis on Target Strength of the Filled Spherical Elastic Shell

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IOP Conference Series: Materials Science and Engineering 2020年第1期813卷

作者： Bing Jia Jihui Wang Guijuan Li Yunfei Chen Science and Technology on Underwater Test and Control Laboratory Dalian Liaoning China

In this paper, the acoustic target strength of spherical shells in water with internal fillers is calculated by using the normal series expansion method, and the effects of metal and non-spherical shell materials, size factors and different fillers on the target strength of spherical shells are analyzed. The results show that for different elastic shell parameters, the influence of the acoustic characteristics of the internal filler on the target strength is quite different. For non-metallic sound transmission spherical shells filled with fluid, only when the sound velocity difference between the filler and the water medium is large, the target strength is greatly improved compared with the corresponding rigid sphere, and the shell size parameters have little effect on the target strength. However, for metal spherical shells with internal fillers, the material and size factors of the shell have a greater impact on its target strength, and the sensitivity to sound velocity mismatch inside and outside the shell is relatively small.

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Image Encryption Using Fractional Order Linear-Nonlinear Chaos

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Journal of Physics: Conference Series 2020年第1期1438卷

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

A fractional order chaos system is first designed. It is a linear-nonlinear hybrid using fractional order logistic map. The fractional order chaos system is closer to the real nature phenomena and has better cryptography features than the integer order chaotic systems in dynamics, such as larger range of key space and almost no periodic windows in bifurcation diagrams. Then, we propose an image encryption scheme employing the superior chaotic features of the fractional order chaos system. Which chaotic sequences generated are used for permutation and addition/subtraction operation of encryption depends on the plaintext image. Security analysis and test results indicate that our encryption scheme has a high efficiency and superior security.

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Experimental Study on Acoustic Attenuation of Bubble Wake

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IOP Conference Series: Materials Science and Engineering 2020年第6期780卷

作者： Jing Han Shuai Lv Zhongpeng Wu Mingwei Zhang Jin Bai Science and Technology on Underwater Test and Control Laboratory Dalian Liaoning 116013 China

When ship sails on the water surface, it will form a wake containing a large number of bubbles for different scales. The existence of bubbles will cause the attenuation of sound waves. In this paper, bubbles with different sizes are generated in the pool by using ceramic tube array. An experimental study on the acoustic attenuation characteristics of sound waves in bubbles was carried out for still water, small bubbles, medium-sized bubbles and large bubbles. Through experimental research, it is found that the existence of bubbles makes the acoustic signal decay obviously. At different frequencies, bubbles decay more than 10dB relative to still water. Large bubbles have the strongest attenuation effect on acoustic signals, averaging over 20dB. The medium and small bubbles are similar to the attenuation of the acoustic signal. The acoustic signal intensity in static water and different scale bubbles is basically the same as the frequency.

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Analysis of Influence Degree of Hydrological Parameters for Wave Induction Electric Field

Analysis of Influence Degree of Hydrological Parameters for ...

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IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Pei Cui Jun Shao Shaojie Pang Science and Technology on Underwater Test and Control Laboratory Dalian Scientific Test and Control Technology Institute Dalian China

ISBN: (纸本)9781538653746

The underwater electromagnetic field of marine environment is the background for the underwater vehicle to complete underwater electromagnetic communication. The characteristics of the electromagnetic field of marine environment directly affect the quality of underwater electromagnetic communication. And as the main source of the electromagnetic field of marine environment, the wave induced electromagnetic field is an important research object for domestic and foreign relevant personnel. Because of its complicated production mechanism, many hydrological parameters affect its amplitude distribution. The hydrological impact parameters of it are combed based on the analysis results of wave induced electric field theory in this paper. Combined with the actual hydrological parameter values, we determined the degree of influence of each hydrological parameter in the wave induced electric field and gave the key parameters affecting its amplitude. The research results of this paper can provide references for the establishment of wave induced electric field observation methods and statistical models. Based on the research results of this paper, the amplitude and spatial variation of underwater electric field in different depths under different hydrological parameters can be determined. The conclusions can provide reference information for electromagnetic communication frequency and depth selection of underwater vehicle.

关键词： Electric fields Magnetic fields Surface waves Sea surface

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Comparative Analysis of Contribution Degree of Environmental Parameters in Wave Induced Magnetic Field

Comparative Analysis of Contribution Degree of Environmental...

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IEEE International Conference on control Science and Systems Engineering (CCSSE)

作者： Pei Cui Junjun Lv Jun Shao Shaojie Pang Science and Technology on Underwater Test and Control Laboratory Dalian China Dalian Scientific Test and Control Technology Institute Dalian China

ISBN: (纸本)9781538678886

Wave induced magnetic field is the main field source form in the natural electromagnetic field. It is the object of study and calculation by geophysicists in various countries. Each of the environmental parameters in the wave induced magnetic field contributes differently to the amplitude of the field source. In this paper, based on the theoretical model of wave induced magnetic field and the variation of the main environmental parameters of offshore waters in China, the contribution of each environmental parameter to the amplitude of the induced magnetic field of the waves is calculated. By classifying environmental parameters, we extract its key parameters. The research results of this paper will provide support for the design of underwater magnetic field observation methods in the marine environment and its characteristics prediction. In addition, based on the theoretical model and analysis results, the range of magnetic field amplitude induced by the waves can be estimated, and the spatial variation of amplitudes in different sea areas can be effectively predicted based on the acquired environmental parameters in a number of unknown sea areas. The research results can also provide theoretical support for marine environmental monitoring, exploration of seabed mineral deposits, and electromagnetic communication of underwater vehicles.

关键词： Magnetic fields Surface waves Sea surface Conductivity Electromagnetic fields

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Modeling of Radiated Noise Passing Characteristic for Ship in Different Marine Environments

Modeling of Radiated Noise Passing Characteristic for Ship i...

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2018 3rd International Conference on Modelling, Simulation and Applied Mathematics(MSAM 2018)

作者： Liang Zhang Chunxia Meng Dalian Institute of Measurement and Control Technology Science and Technology on Underwater Test and Control Laboratory

The ship radiated noise is used as information sources of passive detection and classification, at the same time, the realistic simulation of ship radiated noise signals is an effective way to deceive the passive acoustic detection equipment. In this paper, we analyze a large amount of near field radiation noise data under the same conditions for a certain type of ship, and obtain the statistical characteristics of the radiated noise spectrum;a set of random numbers satisfying this statistical feature was generates using a probability density function to describe the spectrum of the underwater noise source. Use it as an input signal to the filter, an ocean channel filter with arbitrary acoustic velocity profile was established on ray acoustics, and the Fourier synthesis algorithm was used to reconstruct the passing characteristics of the radiated noise signal received by the hydrophone at any depth in a typical shallow sea and deep sea. Finally, the effectiveness of the reconstructed radiated noise waveform is analyzed. The results show that the correlation between the reconstructed signal and the measured ship signal in the frequency domain is greater than 0.8. The modeling method in this paper is very important for the analysis of underwater acoustic signals in the laboratory environment.

关键词： marine environment radiated noise for ship passing characteristic

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