超声散斑相关法测量转角的相关性研究

Correlation of rotating angle measurement by the ultrasonic speckle correlation method

对于在用超声散斑相关法测量时,转角对不同强度散斑的影响及散斑场相关性和转角之间的关系做了研究。为了分析界面位移前后,不同照射区域对散斑振幅是如何影响的,文中把超声照射区域化为M个反射基元,利用大量反射基元的统计规律,推导出了散斑形貌误差和统计误差对散斑场的影响关系,这个关系就是散斑的振幅越大,受转角大小的影响就越小;转角越大统计误差对散斑强度的影响就越大。为了验证这个结论作者建立了实验系统,实验结果显示理论分析是正确的。

This paper studies the effect of rotating angle on speckle＇s intensity and the relationship between ultrasonic speckle correlation and the rotating angle by ultrasonic speckle correlation method. In order to make clear how the changed area influences the amplitude of the speckle, the irradiated area is divided into M reflecting element. From the statistical principle of large number reflecting element, it is studied that how the speckle profile error and the statistical error influence the speckle＇s field. It is found that： as the intensity of speckles increases, the influence of profile error on the speckle＇s field decreases; as the rotation angle increases, the influence of the statistical error on the speckle＇s intensity increases. An experimental system is established for verifying the above conclusion, the experimental results show the theoretical analysis is correct.