From rtakahashi@uni-hamburg.de Thu Sep 14 18:01:36 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!rtakahashi
From: rtakahashi@uni-hamburg.de (Raj Takahashi)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Sep14.180136.8920@uni-hamburg.de>
Date: Thu, 14 Sep 1995 18:01:36 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).

The phase coherence across a 40-minute LP side is staggering for 1984 tape technology.

-- 
Raj Takahashi | rtakahashi@uni-hamburg.de
PGP Key fingerprint: 024B 6EB3 8D45 B674
"Keep the channels open."

From bsmirnov@demon.co.uk Fri Sep 15 08:31:36 1995
Path: ashpoly!cascade!mxgate!coyoacan!demon!bsmirnov
From: bsmirnov@demon.co.uk (Bastien Smirnov)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Sep15.083136.6952@demon.co.uk>
Date: Fri, 15 Sep 1995 08:31:36 GMT
References: <1995Sep14.180136.8920@uni-hamburg.de>
Organization: Demon Internet Services UK
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In article <1995Sep14.180136.8920@uni-hamburg.de>, rtakahashi@uni-hamburg.de (Raj Takahashi) writes:
> 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.

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.

-- 
Bastien Smirnov
Opinions expressed are solely my own and not those of Demon Internet Services UK.
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