针对窗口傅里叶变换和连续小波变换方法对于低速缓变过程速度分辨不足的缺点，提出了一种基于傅里叶变换的位移模式数据处理新方法。该方法不是通过分析信号频率获得速度，而是采用改进的傅里叶变换方法直接分析信号相位得到位移，进而求导得到速度信息。用新方法对电炮平面碰撞实验数据进行处理，很好地反映了铁样品的低压弹塑性过程。新方法不仅充分利用了原始数据的信息量，而且在低速段具有较高的速度分辨能力，可以作为窗口傅里叶变换方法和连续小波变换方法的有益补充。

The short time Fourier transform (STFT) and continuous wavelet transform (CWT) cannot resolve slowly varying velocity at low velocity stage in most photonic Doppler velocimetry (PDV) data. A new analysis method based on Fourier transform is presented to overcome this shortcoming. Instead of extracting the frequency of interference signal for velocity analysis, the new method uses a modified Fourier transform to analysis the phase of signal, and converts phase to displacement or velocity. The validity of the proposed method is examined in experimental data of a plate- impact experiment, which distinguishes the elastic- plastic properties of Fe sample. The method not only uses all sampling points of the raw data, but also has a higher velocity resolutions especially for low velocity stage. The method is a supplement to STFT and CWT method.