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论述了ＤＦＴ连续性，并推出ＤＦＴ谱的插值公式。提出了通过迭代确定ＤＦＴ的幅值极大值以寻找信号参数，并编制出寻找ＤＦＴ幅值峰值的抛物线迭代程序，该迭代只需几步即可得到相当准确的频率。考察了ＤＦＴ的频率分辨力和精度。比较了窗函数对ＤＦＴ精度影响，指出全景分析时采用汉宁窗，而局部分析时采用矩形窗。
Discusses the DFT continuity and introduces the interpolation formula of DFT spectrum. It is proposed to find out the signal parameters by iteratively determining the maximum value of the DFT amplitude and to develop a parabolic iterative procedure for finding the peak amplitude of the DFT. The iteration can obtain a fairly accurate frequency in just a few steps. Investigated the DFT frequency resolution and accuracy. The influence of window function on the accuracy of DFT is compared. It is pointed out that the Hanning window is used in the panoramic analysis and the rectangular window is used in the local analysis.