Research On Adaptive Beamforming Algorithm Of Parametric Sonar

Beam former is the core part of parametric array sonar. Adaptive beam forming algorithm is proposed from beam forming, whose purpose is to improve the performance of detecting and identifying of parametric array sonar. Marine resources are rich. Because the underwater detection technology is not mature enough, the exploration and exploitation of marine are not taken seriously. With the continuous development of electronic technology, parametric array technology being mature. Parametric array sonar can be able to complete the underwater target detection and identification. Because of using adaptive beam forming algorithm to the parametric array sonar, the reception of the echo signal processing is more accurate. This thesis main contents four parts.Firstly, this paper analyzes the parametric array sonar shallow acoustic environment model. It analyzes desired signal how to pass the underwater acoustic channel. Typical shallow sound field model is established to explore the most important sound field environment’s interference, noise and reverberation. At the same time, through environmental model, this thesis analyzes underwater acoustic channel of the parametric array sonar signal propagation.Then according to the basic principles of beam forming, this paper explores the conventional beam former with adaptive beam former of difference and contact. Using MATLAB simulation analysis of various arrays, to explore the advantages and disadvantages between different arrays. This work is the premise of adaptive beam synthesis algorithm designing. Specific algorithm requires an array with a specific order.Then from the classic beam former adaptive algorithm, this thesis delve into the advantages and disadvantages of the various algorithms. Focus on the minimum mean square error algorithm, RLS algorithm and direct matrix inversion(DMI) algorithm. Using MATLAB computer simulation analysis, this paper analyzes convergence, stability and so on.Finally, based on special underwater acoustic environment of parametric array sonar, and the best features of arrays, this paper designs adaptive beam former. The actual project, adaptive beam former is ultimately converge to the optimum processor and real-time changing according to the environment. The received signal is a low frequency and small signal. Therefore, based on the classic adaptive algorithm and improving algorithm, this thesis can deal reception of such signal.