Fast Fourier Transform | SpringerLink

The “Fast Fourier Transform,” referred to as the “FFT,” is a computational tool that facilitates signal analysis, such as Power Spectral Analysis, by means of digital computers. The FFT is a method for efficiently computing the Discrete Fourier Transform (DFT) of a digitized time series or discrete data samples. The FFT takes advantage of the symmetrical properties of periodic sinusoidal waveforms. Before development of the FFT, transformation of signals into the frequency domain was done by the standard trigonometric Fourier Series computational procedures.