Shallow Water Multibeam Sounder Digital Model Design And Simulation

Ocean takes up70%of the Earth’s surface. Along with the expansive growth of the world’s population, the shortage of land resource becomes increasingly severe. Thus, ocean exploration and study as well as the exploitation and utilization of ocean resources are drawing more and more attention from countries worldwide. In human’s ocean activity of exploitation and utilization, ocean surveying plays a significant role as a foundation. It can be said that multi-beam sounding device is the most effective ocean sounding device for ocean surveying. At present, there are three common methods for data processing of submarine topography including ex-post processing, tracking and interaction. Now, though good softwares are provided for image post-processing, they lack real time performance, unable to satisfy the requirements of some high real-time operations. Though the tracking method shows some real-time performance, it cannot diversify the expression types of real-time sounding data or fully display the information. Interaction means realizing real-time expression in the process when topographic data are dynamically emerging; meanwhile, the conditions for the emergence of topographic data can be altered through interactive operation, and besides, problems can be directly modified in the uninterrupted process while finding out the problems timely. Now, research institutes at home and abroad have made many explorations on the research of multi-beam sounding system, but the system is only designed with the functions of sonar device control, real-time data collection and simple display of real-time data, which stays at the experimental stage basically. In particular, no complete display and control system is designed for the multisource and numerous real-time data and the complicated working mechanism of multi-beam sonar system in deep water。This paper makes an in-dept study on the drawbacks of multi-beam sonar display and control system at home and abroad. First, restricted by experimental conditions, the emission of multi-beam and the modeling of echo signal are invisible. In combination with acoustics knowledge and based on the basic theory of multi-beam, this paper builds the models for the emission of multi-beam, the transmission path in the sea, sea noise, and bottom reverberation, and meanwhile carries out3D visible display. Second, the major task is to make improvements in man-machine interaction in the process of real-time information collection by software. Usually, for the operations of some projects, it is necessary to search for objects in certain characteristic shapes on the seabed, such as unexploded torpedo and the sunken ships. Because of good interactive performance, the first scanning can be roughly carried out by slightly magnifying the angle of beam emission to find out several suspected points based on display results. Afterwards, the scanning angle of suspected points can be reduced to realize accurate scanning by way of frequency range favorable for small angle scanning. This will thus decrease the computational burden as well as equipment complexity and cost, and speed up the scanning.The experiment result shows the primitive3D submarine topography. It turns out that the topographical restoration can find the objects in certain characteristic shapes in a real-time and effective way.