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NAV READY · TYPE SHORTCUT · ENTER EXECUTES

Fourier transform

Category
DSP
Definition
A layered explanation of the Fourier transform as a change of viewpoint from position to frequency, covering wave matching, phase, inversion and the published Riemann Console Fourier bridge.
Math Level
TECHNICAL
Index Excerpt
Fourier transform; frequency; phase; spectrum; inversion; wave matching; completed sideband; T2

Fourier transform

The Fourier transform rewrites a function or signal in terms of frequency components rather than its original position- or time-based description.

In one common convention, a function f(x)f(x) is transformed into a frequency-domain function f^(ξ)\widehat f(\xi) by integrating f(x)f(x) against complex oscillations. Different fields use different normalisation constants, but the underlying idea is the same.

Fourier transforms are fundamental in harmonic analysis, signal processing, partial differential equations, probability and mathematical physics.

See also: Fourier analysis, spectral density. .

Related glossary terms

  1. [..]Fourier analysisGLOSSARY · DSP
  2. [..]Spectral densityGLOSSARY · DSP

Read this term in context

  1. [..]Bochner's theoremARTICLE · ART-RC-0067
  2. [..]Fourier analysisARTICLE · ART-RC-0065
  3. [..]Spectral densityARTICLE · ART-RC-0069
  4. [..]Spectral measureARTICLE · ART-RC-0068
  5. [..]Translation invarianceARTICLE · ART-RC-0062
  6. [..]What is positive definiteness?ARTICLE · ART-RC-0005