傅里叶分析方法是信号分析的最基本方法，傅里叶变换是傅里叶分析的核心，通过它把信号从时间域变换到频率域，进而研究信号的频谱结构和变化规律。-Fourier analysis is the most basic method of signal analysis, Fourier transform is a Fourier analysis of the core, through which the signal　the time domain to the frequency domain, and then study the spectral structure and changes of the signal.