Tutorial on scaling of the discrete fourier transform and the implied physical units of the spectra of time-discrete signals
Paper in proceeding, 2020

The combination of the time-discrete property of digital signals together with the commonly employed definition of the discrete Fourier transform (DFT) can cause ambiguity when interpreting magnitude spectra with respect to the physical unit of the signal under consideration. Standardized scaling of spectra increases the comparability of frequency-domain data that are published in scientific articles or data sheets of commercial products. We present and discuss in this tutorial a collection of the most relevant scaling options for DFT spectra to yield amplitude spectra, power spectra, and power density spectra, and we illustrate how an implied physical unit of the underlying signal is reflected by the magnitude of the spectrum. The tutorial is accompanied by Matlab/Octave scripts that demonstrate the different cases.

Author

Jens Ahrens

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Carl Andersson

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Patrik Höstmad

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Wolfgang Kropp

Chalmers, Architecture and Civil Engineering, Applied Acoustics

148th Audio Engineering Society International Convention

148th Audio Engineering Society International Convention 2020
Vienna, Virtual, Online, Austria,

Subject Categories

Atom and Molecular Physics and Optics

Signal Processing

Other Electrical Engineering, Electronic Engineering, Information Engineering

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1/3/2024 9