From reriksson@uu.net Sat Jun 01 22:23:23 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uu!reriksson
From: reriksson@uu.net (Raj Eriksson)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Jun01.222323.4956@uu.net>
Date: Sat, 01 Jun 1996 22:23:23 GMT
Organization: UUNET Technologies, Falls Church VA
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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.
Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.

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

-- 
Raj Eriksson -- UUNET Technologies, Falls Church VA
"In theory there is no difference between theory and practice."

From vmuller@pipeline.com Mon Jun 03 00:27:23 1996
Path: ashpoly!cascade!bigsur!pipeline!vmuller
From: vmuller@pipeline.com (Valeria Müller)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Jun03.002723.9765@pipeline.com>
Date: Mon, 03 Jun 1996 00:27:23 GMT
References: <1996Jun01.222323.4956@uu.net>
Organization: The Pipeline Internet Network
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In article <1996Jun01.222323.4956@uu.net>, reriksson@uu.net (Raj Eriksson) 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.

Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless.

Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs.

-- 
=== Valeria Müller ===
Dept of Electrical Engineering, The Pipeline Internet Network
"Measuring a record you own is listening, not piracy."

From dsantos@earthlink.net Wed Jun 05 00:00:23 1996
Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!dsantos
From: dsantos@earthlink.net (Dong-hyun Santos)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Jun05.000023.6862@earthlink.net>
Date: Wed, 05 Jun 1996 00:00:23 GMT
References: <1996Jun01.222323.4956@uu.net> <1996Jun03.002723.9765@pipeline.com>
Organization: EarthLink Network
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In article <1996Jun03.002723.9765@pipeline.com>, vmuller@pipeline.com (Valeria Müller) writes:
> Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless.

Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock.

PGP Public key available via finger or upon request.

-- 
Dong-hyun Santos -- EarthLink Network
"5 sigma is a discovery. 7 is a question."