提高FFT法测量等距干涉条纹频率精度的一种简便方法

A Method for Improving Precision in Determining Interference Fringe Frequence with FFT

ＦＦＴ频谱分析技术用于测试等距直线干涉条纹的频率时，要求数据截断长度等于干涉条纹周期的整数倍，才能得到准确的测量值，这条件在实际测试中很难满足，本文给出一种方法，可不用考虑该条件，只利用ＦＦＴ的结果就能很方便地得到与连续富里叶变换相一致的干涉条纹频率值。

A method for determining a frequency of equidistant and straight interference fringes is presented, which is based on corrected peak position of discrete spectrum of the fringe patterns when a spatial truncation length of data isn't integer times of a period of the interference fringes. The results of computer simulation showed the frequency value from this method proposed to be right, it is as good as which from FT.