From gjohansson@hanse.de Wed Aug 24 07:56:04 1994
Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!gjohansson
From: gjohansson@hanse.de (Graham Johansson)
Newsgroups: comp.dsp
Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Aug24.075604.2504@hanse.de>
Date: Wed, 24 Aug 1994 07:56:04 GMT
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Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.

A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics.
With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu.

-- 
Graham Johansson -- Hanse-Netzwerk Hamburg
"Row 14. No joke."

From lvasiliev@demon.co.uk Fri Aug 26 09:59:04 1994
Path: ashpoly!cascade!bigsur!demon!lvasiliev
From: lvasiliev@demon.co.uk (Liam Vasiliev)
Newsgroups: comp.dsp
Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Aug26.095904.6772@demon.co.uk>
Date: Fri, 26 Aug 1994 09:59:04 GMT
References: <1994Aug24.075604.2504@hanse.de>
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In article <1994Aug24.075604.2504@hanse.de>, gjohansson@hanse.de (Graham Johansson) writes:
> Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.

Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz.

Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns.

-- 
Liam Vasiliev -- Demon Internet Services UK
"5 sigma is a discovery. 7 is a question."

From dnilsson@kiae.su Sun Aug 28 04:02:04 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!kiae!dnilsson
From: dnilsson@kiae.su (Dmitri Nilsson)
Newsgroups: comp.dsp
Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Aug28.040204.9169@kiae.su>
Date: Sun, 28 Aug 1994 04:02:04 GMT
References: <1994Aug24.075604.2504@hanse.de> <1994Aug26.095904.6772@demon.co.uk>
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In article <1994Aug26.095904.6772@demon.co.uk>, lvasiliev@demon.co.uk (Liam Vasiliev) writes:
> Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz.

The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26!

-- 
Dmitri Nilsson | dnilsson@kiae.su
PGP Key fingerprint: 5238 056A DF38 315F
"Keep the channels open."