From bkim@tum.de Fri Jun 14 13:07:43 1996
Path: ashpoly!cascade!mxgate!coyoacan!tum!bkim
From: bkim@tum.de (Bill Kim)
Newsgroups: comp.dsp
Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1996Jun14.130743.7848@tum.de>
Date: Fri, 14 Jun 1996 13:07:43 GMT
Organization: Technische Universität München
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Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.
At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs.

MATLAB script available upon request via email.

-- 
Bill Kim -- Technische Universität München
"Tape doesn't lie at 02:14. Ears do."

From dlindqvist@illinois.edu Sat Jun 15 04:09:43 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!dlindqvist
From: dlindqvist@illinois.edu (Dong-hyun Lindqvist)
Newsgroups: comp.dsp
Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1996Jun15.040943.3639@illinois.edu>
Date: Sat, 15 Jun 1996 04:09:43 GMT
References: <1996Jun14.130743.7848@tum.de>
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In article <1996Jun14.130743.7848@tum.de>, bkim@tum.de (Bill Kim) writes:
> Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.
> A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.

I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection.

-- 
Dong-hyun Lindqvist
Tape trading list upon request. SASE required for international mail.

From pvasiliev@purdue.edu Mon Jun 17 05:35:43 1996
Path: ashpoly!cascade!bigsur!purdue!pvasiliev
From: pvasiliev@purdue.edu (Pavel Vasiliev)
Newsgroups: comp.dsp
Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1996Jun17.053543.1984@purdue.edu>
Date: Mon, 17 Jun 1996 05:35:43 GMT
References: <1996Jun14.130743.7848@tum.de>
Organization: Purdue University Engineering Computer Network
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In article <1996Jun14.130743.7848@tum.de>, bkim@tum.de (Bill Kim) writes:
> Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform.

-- 
Pavel Vasiliev
Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network.
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