基于矢量水听器的南海海洋背景噪声测试

Measurement of Background Noise of the South China Sea Based on Vector Hydrophone

矢量声压振速联合处理建立在信号的声压和振速相位基础上,海洋环境边界影响将改变矢量声场声压振速的幅度和相位特性.首先根据南海环境条件结合水下目标辐射噪声测量,采用声场矢量简正波理论估算海面非相干偶极子噪声和水下点声源矢量强度随深度的变化,然后设计了可用于深海海域噪声测量的矢量水听器测试系统,获取了南海海域典型深度上的背景噪声矢量强度并进行了特性分析.结果表明:深海背景噪声谱级在500 Hz以下基本上不随深度变化,在500 Hz^3 kHz频段浅深度背景噪声谱级略高于较深深度的背景噪声;振速垂直分量的背景噪声要小于声压和振速水平分量的噪声谱级.

The vector sound pressure and particle velocity combined treatment was established based on the signal sound pressure and particle velocity phase, but the surface and bottom will change amplitude and phase properties of sound pressure and velocity in vector fields. Firstly, according to the South China Sea environ- mental conditions combined with underwater target radiated noise measurement and used sound field vector normal mode theory to estimate the dipole sea incoherent noise and the underwater point source vector intensi- ty variation with depth. Secondly, noise measuring system based on vector was designed for noise measuring in deep sea and it was analyzed that typical depth ambient noise data was received by vector sensor system in South China Sea. It showed that the noise spectrum level of ambient noise below 500 Hz basically does not change with depth, the noise spectrum level of ambient noise from 500 Hz to 3 kHz at a shallow depth was higher than a deeper depth, the noise level of vertical velocity spectrum level of ambient noise was less than the sound pressure, horizontal particle velocity spectrum level in deep ocean.