基于光纤矢量水听器的浅海噪声矢量场特性研究

基于简正波理论分析了浅海噪声矢量场声压和质点振速的强度特性,仿真了浅海声压和质点振速的噪声强度在深度和频率上的变化特性,噪声矢量场强度特性仿真结果与实验测量结果一致。针对声场测量的有效性,给出了加速度通道自噪声谱级和灵敏度必须满足的关系式,并提出了降低自噪声对接收系统影响的两种措施。最后分析并对比了系统自噪声谱级和海洋环境噪声谱级,结果表明,声压通道的自噪声比环境噪声谱级低20 d B左右,Y通道和Z通道的自噪声比环境噪声低3.5 d B以上,X通道的自噪声谱级在200 Hz附近与环境噪声谱级最为接近,约比环境噪声低1.5 d B。

Study of vector noise field characteristics in shallow water by fiber optical vector hydrophone

Vector noise field characteristics in shallow water are analyzed with normal mode theory, and the intensity distributions of pressure and particle velocities in shallow water vector noise field are simulated, which are well in agreement with experiment results. The expressions of system noise intensity and sensitivity, which meet the validity of data record, are presented, and two methods of suppressing the influence of system noise on fiber-optical vector hydrophone system are also proposed. System noise and ambient noise are tested with the fiber-optical vector hydrophone system, and analyzed in different frequency bands. The result shows that the self-noise spectrum level in pressure channel is 20 dB lower than ambient noise level, and the self-noise spectrum levels in Y and Z acceleration channels are lower than ambient noise level by 3.5 dB more. While the self-noise spectrum level in X acceleration channel is nearest to ambient noise level at 200 Hz (about 1.5 dB lower).