From jchoi@purdue.edu Tue Sep 10 19:23:00 1996 Path: ashpoly!cascade!transat!ukc!fennimore!purdue!jchoi From: jchoi@purdue.edu (Joachim Choi) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep10.192300.5266@purdue.edu> Date: Tue, 10 Sep 1996 19:23:00 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Joachim Choi US Robotics Courier V.34 @ 9600 Telebit bps "Tape doesn't lie at 02:14. Ears do." From srobertson@berkeley.edu Thu Sep 12 01:16:00 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!berkeley!srobertson From: srobertson@berkeley.edu (Sun-mi Robertson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep12.011600.6822@berkeley.edu> Date: Thu, 12 Sep 1996 01:16:00 GMT References: <1996Sep10.192300.5266@purdue.edu> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Sep10.192300.5266@purdue.edu>, jchoi@purdue.edu (Joachim Choi) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. If you are posting from AOL, please read RFC 1036 before posting again. -- Sun-mi Robertson *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From msmirnov@pacbell.net Sat Sep 14 00:58:00 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!pacbell!msmirnov From: msmirnov@pacbell.net (Marisol Smirnov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep14.005800.4766@pacbell.net> Date: Sat, 14 Sep 1996 00:58:00 GMT References: <1996Sep10.192300.5266@purdue.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Sep10.192300.5266@purdue.edu>, jchoi@purdue.edu (Joachim Choi) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Marisol Smirnov "In theory there is no difference between theory and practice." PC-9821Ap2 (NEC) / System 7.5.1 From lkowalski@cern.ch Sun Sep 15 12:59:00 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!cern!lkowalski From: lkowalski@cern.ch (Liam Kowalski) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep15.125900.8340@cern.ch> Date: Sun, 15 Sep 1996 12:59:00 GMT References: <1996Sep10.192300.5266@purdue.edu> <1996Sep12.011600.6822@berkeley.edu> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Sep12.011600.6822@berkeley.edu>, srobertson@berkeley.edu (Sun-mi Robertson) writes: > Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. > If you are posting from AOL, please read RFC 1036 before posting again. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Liam Kowalski Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva. ------------------------------------------------------------