Fast Fourier Transform

An algorithm, or digital calculation routine, that efficiently calculates the discrete Fourier transform from the sampled time waveform. In other words it converts, or "transforms" a signal from the time domain into the frequency domain.

Applications

Historical Notes

  1. 1965 Tukey and Cooley publish a paper introducing the "Fast Fourier Transform" algorithm.

Bins

The individual frequencies at which the amplitudes are calculated, commonly called lines.

Line Spacing

The frequency difference between two adjacent bin centers or lines.

Narrowband Analysis

Another way of saying FFT analysis.

Windowing

An amplitude weighting of the time signal used with gated continuous signals to give them a slow onset and cut-off in order to reduce the generation of side lobes in their frequency spectrum.

See also: Blackman Window, Bohman Window, Cauchy Window, Discrete Fourier Transform, FFT Analyser, Fourier Transform, Hamming Window, Hanning Window, Kaiser Bessel Window, Leakage, Overlap Processing, Picket Fence Effect, Rectangular Window, Signals, Windowing.

Previous PageView links to and from this pageNext Page

Subjects: Analysis Mechanical Engineering Noise & Vibration Physics Signal Processing


Weblinks:
Bruel & Kjaer - Technical Reviews These documents give detailed articles on measurement and signal processing theory.