能量法估计全息面信噪比研究

Estimation of the signal to noise ration in the planar acoustical holography based on energy method

在近场声全息技术中,全息面信噪比是一个非常重要的参数,但无法直接测量得到。为了解决该问题,给出了基于能量法的波数域内信噪比估值公式,并根据该公式分析估值误差的来源,指出全息面采样间隔对估值具有重要影响。为了判别估值是否准确,提出了选取全息面不同区域的数据进行重复估计的判别方法。当估值不准确时,指出可以通过减小全息面采样间隔来降低估值误差。仿真给出满足不同误差条件的不同采样间隔所对应的最大信噪比估值,可作为实际应用中的参考。

The signal to noise ratio （SNR） is a very important parameter in theplanar acoustical holography. However, it can＇t be determined directly. To solve the problem, a formula in ＇-space＇ is given based on theenergy method. According to the formula, the sampling interval has a great influence on the SNR estimation value. To determine the accuracy of the estim- ation value, the measurement data on the different areas of the holography surface is chosen to estimate. When the result is not accurate, the estimation value can be improved by decreasing the sampling interval. The maximum estimation value is given in different estimation precision and different sampling interval to provide a reference for practical applications.