傅里叶变换求取叠栅条纹微小位移的精度分析

提出了借助于傅里叶变换提取叠栅条纹相位分布的途径来获得条纹微小位移量的方法中，图像的截断必然会产生频谱泄漏，从而引入数据处理的误差。详细分析了傅里叶变换中频谱泄漏产生的原因及其对测量误差的影响，提出了图像处理时，通过外插值将截断区域延拓为叠栅条纹周期整数倍时可以减小甚至忽略频谱泄漏所引起的相位计算误差，并对此进行了数值模拟以及初步的实验验证，证实了该方法的有效性，为叠栅偏折法应用于微细尺度流动与传热的实验研究提供了有效的技术途径。

Analysis of Measurement Accuracy for Mini-displacement of Moiré Fringe by Fourier Transform

A new data processing method by means of Fourier transform has been developed. In Fourier transform, frequency leakage will surely be caused because of the space-limited extension of fringe pattern in Fourier transform. It will cause measurement error. The reason why frequency leakage is caused is analyzed, the corresponding numerical simulation is presented in detail, and the preliminary experiment is carried out. On the basis of the analysis, the numerical simulation and the experiment, it is proposed that external interpolation continuation of the fringe pattern to any integer times will greatly improve the measurement accuracy. The data processing method will promote the application of moiré deflectometry in micro-scale heat transfer and flow measurement.