A Method for Estimating the Distance of Near-Ocean-Bottom Sources by Combining VLF Underwater Acoustic Field and Scholte Wave Field

2018 5th International Conference on Coastal and Ocean Engineering

Zhao, Han^1 ; Sun, Guiqing^1 ; Zhu, Hanhao^2 ; Yuan, Junxin^1

Institute of Marine Information Science and Technology, Ocean College, Zhejiang University, Zhoushan, China^1

Zhejiang Ocean University, Zhoushan, China^2

关键词: Finite element simulations;    Near field effect;    Passive detection;    Polarization characteristics;    Position information;    Propagation delays;    Under-water sound source;    Very low frequency;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/171/1/012009/pdf
DOI  :  10.1088/1755-1315/171/1/012009

来源: IOP

【 摘 要 】

In order to solve the problems of passive detection of very-low-frequency (VLF) underwater sound sources, this paper proposes a method of estimating sound source distance based on combining underwater sound field and Scholte wave field. VLF sources near the ocean bottom generate the sound field in the water, then seismic waves are excited by the of near-field effect. The surface wave propagating along the ocean bottom interface is the Scholte wave. By deploying a hydroacoustic&seismic-wave joint detection system on the ocean bottom, the acoustic field and the Scholte wave field excited by the source can be collected. Due to the different physical properties of water acoustics and Scholte waves, the Scholte waves can be distinguished by analysing the polarization characteristics of the captured signals. Due to the different velocity between the underwater acoustics and Scholte waves, the propagation delays to the joint detection system are also different, and the delay difference can be obtained by the correlation method. Combined with the surrounding parameters, the distance of the target source can be determined. Theoretical analysis and finite element simulation experiments show that this method can estimate the position information of near-ocean-bottom VLF underwater sources in the ideal case.