From msokolov@cmu.edu Fri Oct 06 22:17:09 1995 Path: ashpoly!cascade!bigsur!cmu!msokolov From: msokolov@cmu.edu (Mikhail Sokolov) Newsgroups: comp.dsp Subject: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Oct06.221709.4423@cmu.edu> Date: Fri, 06 Oct 1995 22:17:09 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Mikhail Sokolov *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From dwatanabe@hanse.de Sun Oct 08 17:00:09 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!dwatanabe From: dwatanabe@hanse.de (Diego Watanabe) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Oct08.170009.5604@hanse.de> Date: Sun, 08 Oct 1995 17:00:09 GMT References: <1995Oct06.221709.4423@cmu.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Oct06.221709.4423@cmu.edu>, msokolov@cmu.edu (Mikhail Sokolov) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > 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. -- Diego Watanabe Tape trading list upon request. SASE required for international mail.