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Re: swept sine accuracy

Am 05. Mär. 2009 um 19:13 Uhr schrieb James W. Beauchamp:

>If you use a
>swept sine wave to measure the frequency response of a linear
>system, what is the limitation on the speed of the sweep in
>terms of how accurate the result would be? I imagine it has
>something to do with how smooth the actual frequency response 
>is. If it has some pronounced bumps, they could be smoothed
>out if the sweep is too fast.

According to

	author = {{M. A. Poletti}},
	title = {{Linearly Swept Frequency Measurements, Time-Delay Spectrometry, and the Wigner Distribution}},
	journal = {J. Audio Eng. Soc.},
	year = {1988},
	volume = {36},
	number = {6},
	pages = {457-468}

the sweep rate k [Hz/s] of a linearly swept measurement should satisfy
the constraint

    k << 1 / (pi * t^2)

where t is the length of the impulse response.

Christian Borß, Dipl.-Ing.          ||   Institut für Kommunikationsakustik
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