基于激光干涉式水听器的近海海洋环境噪声测量研究

Offshore marine ambient noise measurement based on laser interferometer hydrophone

在迈克尔逊干涉原理的基础上设计了激光干涉式水听器,通过跟踪补偿的方式提高了水听器的抗干扰能力。通过对水听器声压误差进行分析,认为振动膜是声压误差的主要来源,且可以通过振动膜材料的选择得到一定程度上的消除。在某近海海域获得的实测数据表明,水听器对噪声声压的测量精度较高,具有良好的频率响应能力,与理论模型的对比实验也一定程度上验证了数据的准确性。在近海海域,风成噪声和船只辐射噪声是海洋环境噪声测量的主要噪声源。在此,对3种风速下测得的海洋环境噪声谱级进行了计算,并与Knudsen曲线进行了比对,结果显示,测量数据与Kundsen曲线拟合度较好,经测量,船只辐射噪声主要集中在350~500Hz频率范围内。

Sound pressure is an important parameter for marine ambient noise monit oring.A laser interferometric hydrophone is designed based on Michelson interferometry to measure the offshore sound pressure of marine ambient noise.By tracking compensation method,the immunity from interference of the hydrophone is improved to some extent.Error analysis based on field data shows that the vibrating membran e is the main source of the sound pressure errors,which can be eliminated to a certain extent by appropriate vi brating membrane materials selection and optical-path optimization design.Offshore data show that hydropho ne pressure measurement is of high precision,and with a satisfactory frequency response.Comparative experiments w ith theoretical models can also verify the accuracy of the data.In coastal waters,wind noise and ship radiate noise are the main sources of marine ambient noises.Here,marine am bient noise spectra under three different wind speeds are calculated,and Kundsen curves are compared. Results show that measured data and Kundsen curve fitting are better both in trend and value,and the static noise source model is prevalence of a difference of about 20dB.In addition,the measurement of vessel radiation noise is mainly concentrated in frequency range of 350-500Hz.