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Study on a Novel combined Fiber Optic Vector Hydrophone

Author: WangFuYin
Tutor: XiongShuiDong；LuoHong
School: National University of Defense Science and Technology
Course: Optical Engineering
Keywords: Vector Hydrophone Fiber-optic hydrophone Differential pressure Standing wave tube
CLC: TB565.1
Type: Master's thesis
Year: 2011
Downloads: 36
Quote: 0
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Abstract

Fiber vector hydrophone as a new kind of underwater acoustic sensor relative to the traditional scalar hydrophone demonstrated many advantages, various types of fiber optic vector hydrophone endless stream. States also have to carry out the fiber vector hydrophone into array technology, but more research is concentrated in the shore-based array, towed array applications, factors such as jitter and variable-speed drag force on the cable fiber vector hydrophone the special requirements, to carry out the optical fiber vector hydrophone towed array can be used to reduce the axial acceleration sensitivity is of great significance. The paper analyzes the characteristics and technical requirements of the fiber vector hydrophone towed array, integrated differential fiber vector hydrophone with vibration of the advantages and disadvantages of fiber optic vector hydrophone, an axial pressure differential radial Forking combination vector the hydrophone structure, and theoretical and experimental research. The main research content and results are as follows: 1, working mechanism and the basic structure of the differential pressure fiber vector hydrophone study. Thin shell theory of the air cavity structure sound pressure sensitivity of the sensing primitives theoretical analysis and parametric design, developed on the basis of the two axial differential pressure sensing primitives, the test phase of the sound pressure sensitivity with the theoretical analysis. the results are basically the same, the error is less than 3 dB. Modular fiber vector hydrophone system design, the design of the optical system structure based on the the dual interferometer one-dimensional differential pressure and demodulation system, a working band, and noise performance analysis, also pointed out that two sound pressure sensing primitives spacing required less than λmin / 7, under which determine the the modular fiber vector hydrophone overall package size, a combination of vector hydrophone system after the completion of the two-dimensional structure with vibration parameters design production and integration. 3, the vector of modular fiber optic hydrophone plane traveling wave field and standing wave field test study analyzed two the pressure sensing primitive sensitivity differences and measurement error on the the Differential Pressure fiber vector hydrophone phase sensitivity and directivity of the sound pressure, and in the standing wave tube performance test, the test results show that at 20 ~ 1250 Hz frequency band, the combination vector hydrophone each axis having a frequency response more consistent with the theoretical curve characteristics, two with vibration shaft and differential pressure axis at 1000 Hz sound pressure phase sensitivity respectively of -153.0 dB -149.9 dB and -147.4 dB re rad / μPa, the differential pressure shaft measured 80 ~ 630 Hz four frequency points on the directivity with the pit depth of more than 35 dB. The test results show that the pressure-difference of the background noise, the pressure-difference of the noise floor with respect to the single pressure sensor primitives reduces aliasing into sampling the relaxation peak of the pass band of 10 dB, reduced by 20 dB or more. Proposed a combination of vector hydrophone axis axial acceleration response of the test methods and test results show that, except a small number of frequencies, the combination of vector hydrophone axis is less than -10 dB re rad / g and the axial acceleration crosstalk, visible anti-axial acceleration performance relative to the three-dimensional with vibration structure has obvious advantages, there are huge potential applied to the towed array.

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CLC: > Industrial Technology > General industrial technology > Acoustic engineering > Underwater Acoustics > Underwater acoustic instruments and equipment > Underwater acoustic transducer , the hydrophone
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