平面近场声全息信噪比估计方法研究

针对全息面复声压信噪比对声场重构结果影响较大、往往不能直接测量问题,采用二维小波分析方法进行全息面信噪比参数估计,分析小波函数、分解层级对信噪比估计准确性影响,明确二维小波分析的参数选取,并以受简谐激励作用的四周无限大障板简支钢板为对象进行辐射声场全息重构仿真分析。结果表明,信噪比参数对实现准确声场全息重构十分重要,用二维小波分析方法进行全息面信噪比参数估计有效且可行。     

Research on Patch Near-field Acoustic Holography Based on HELS Algorithm

A Patch NAH method based on HELS （helmhohz equation least-squares） algorithm is proposed for the measurement requirement of underwater large structures. This method chooses HELS algorithm to approximate the sound field completely, and calculates the sound field data outside the measurement region to enlarge the measurement aperture. It can reconstruct the sound field by the measurement data and the extrapolation data, through the reconstruction result it can be researched for the minimum measurement surface and the range of the extrapolation data in application. The paper analyzes the effect from the different measurement surfaces and different extrapolation ranges to the extrapolation data by simulations, and compares these reconstructed results with the conventional algorithm results. The simulation results indicate that the method can simplify the holographic measuring system, save the cost of the project and improve the accuracy of the sound field reconstruction, which can be effectively used for measuring and analyzing the underwater large structures.