东中国海夏季海洋环境噪声特性分析

海洋环境噪声不仅是水中目标探测的背景干扰声场之一，还可用以反演海洋物理参数。文章基于实测东中国海某海区夏季海洋环境噪声数据，分析其时频特性、统计特性以及风关特性。研究结果表明，试验期间该海区100 Hz以下频段的海洋环境噪声级约为110 dB，频率为100和300 Hz的海洋环境噪声级分别服从自由度为8和6的卡方分布，频率为1 kHz和3 kHz的噪声级服从正态分布；海况对低频海洋环境噪声级概率分布无明显影响，但是对高频段噪声级正态分布的均值和方差会产生一定影响；随着频率的增加，海洋环境噪声级与风速对数间的相关系数逐渐增大，1 kHz以上相关系数在0.6～0.7之间；100 Hz以上频段的噪声谱级基本不随深度发生变化。文中的结果可以为水中目标的探测以及浅海海洋环境噪声的应用研究提供技术支持。

Analysis on the characteristics of ocean ambient noise in the East China Sea in summer

Ocean ambient noise is not only the interference acoustic field with respect to underwater targets detection, but also can be used to invert ocean physical parameters. Based on the ocean ambient noise data measured in a certain area of the East China Sea in summer, the time-frequency characteristics, statistical characteristics and wind-related characteristics of ocean ambient noise are analyzed in this paper. It is shown that during the experiment, the ocean ambient noise spectral level in the frequency band below 100 Hz is about 110 dB. The ocean ambient noise spectral levels at 100 and 300 Hz obey the chi-square distribution with degrees of freedom 8 and 6 respectively, and the noise spectral levels at 1 kHz and 3 kHz obey the normal distribution. Sea conditions have no significant effect on the probability distribution of low-frequency ocean ambient noise spectral levels, but have some effects on the mean and variance of the normal distribution of the noise spectral level in the high frequency range. As the frequency increases, the correlation coefficient between ocean ambient noise level and the logarithm of wind speed gradually increases, and the correlation coefficient above 1 kHz is between 0.6~0.7. The wind noise spectral level above 100 Hz basically does not change with depth. The results of this paper can provide technical support for the underwater target detection and the research on the application of ocean ambient noise in shallow seas.