Effect And Conrrection Of Internal Waves On Multibeam Sounding

Our sea area is relatively large, and has through the long north and south coastline and rich marine resources. The development and utilization of modern marine high-tech and the development and utilization of high-tech marine equipment have provided the premise and guarantee for the development of marine resources. However, the development and utilization of marine resources in China still focus on coastal development and the innovation and support of marine science in China Lack of capacity, technological level limits the development of marine resources development activities.Multibeam sounding technique is the main technical means of using underwater topography to measure the propagation characteristics of sound waves in water. The acoustic bending refraction caused by the change of sound velocity of water is an important source of error that affects its sounding accuracy. The internal waves is a kind of gravity wave which exists widely in the coastal waters of our country, and its amplitude can reach several meters to tens of meters. The common wavelength is between tens of meters and tens of kilometers. Between the floating frequency and the inertia frequency. When the ocean internal waves occur, the huge energy they carry will lead to a higher flow rate of seawater, which will not only pose a serious threat to the offshore oil drilling platform and the underwater submarine, but also the intense density of the surface The speed of sound has changed. Therefore, it is urgent and necessary to study the influence of internal waves on the multi-beam sounding accuracy and explore the error correction method. It is urgent and necessary to invert the inner wavelength and propagation direction of the ocean by improving the accuracy and efficiency of multi-beam sounding.In this paper, the numerical simulation method is used to simulate the vertical displacement and inclination of the velocity of the acoustic velocity when the internal waves is measured. Then, the influence mechanism of the internal wave on the propagation path of the multi-beam acoustic line is analyzed. Based on the analysis of DEM characteristics and submarine terrain fluctuation law, the method of retrieving the approximate propagation information, such as the propagation direction,wavelength and amplitude of the ocean internal wave from the DEM of the seabed, is presented and verified. The ocean internal wave approximation parameter is used to construct the internal wave function, and the acoustic line is re-tracked three-dimensional. The more accurate submarine DEM is used to invert the more accurate ocean wave parameters. The ocean internal wave parameters also weaken the influence of internal waves on multibeam sounding.