根据散斑统计性质测量运动速度的一种新方法

本文提出了一种根据散斑统计性质测量物体运动速度的新方法.在夫朗和费衍射区一点记录运动物体的漫射散斑场随时间的变化,并将记录时城信号作快速付氏变换,转换到频率域上,从功率谱宽度或其所覆面积可推算出物体运动速度.本文从理论上作了分析,推导出物体的运动速度和记录信号功率谱函数的简单关系.实验验证与理论分析吻合一致.该法可作实时测量.

An Method for Measuring Body Velocity By Using Statistical Properties of Laser Speckle

The variance of diffusing speckle field of moving objcct as time function in Fraunhofer zone is recorded. This recorded signal in time domain is translated to. power spectrum in frequency domain by FFT. The width or covered area of power spectrum can be used to describe the object velosity. In this paper, the simple relation between body velosity and power spectrum of recorded data is analized theoritically. The experimental results agree with theoritical analysis. This method can be used to high speed deformation and real time measurement in can uncontact way.