From rtakahashi@berkeley.edu Mon Dec 26 01:56:09 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!berkeley!rtakahashi From: rtakahashi@berkeley.edu (Rodrigo Takahashi) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec26.015609.1862@berkeley.edu> Date: Mon, 26 Dec 1994 01:56:09 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). 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. -- Rodrigo Takahashi | rtakahashi@berkeley.edu PGP Key fingerprint: B1AA C324 5E71 27A6 "Keep the channels open." From csanchez@uu.net Mon Dec 26 14:16:09 1994 Path: ashpoly!cascade!brgate!saturno!uu!csanchez From: csanchez@uu.net (Callum Sánchez) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec26.141609.2281@uu.net> Date: Mon, 26 Dec 1994 14:16:09 GMT References: <1994Dec26.015609.1862@berkeley.edu> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Dec26.015609.1862@berkeley.edu>, rtakahashi@berkeley.edu (Rodrigo Takahashi) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Callum Sánchez "When every node is whole, the channel opens." PC-9821Ap2 (NEC) / NEXTSTEP 3.3 From nkarlsson@rwth-aachen.de Tue Dec 27 17:02:09 1994 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!nkarlsson From: nkarlsson@rwth-aachen.de (Nadine Karlsson) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec27.170209.1730@rwth-aachen.de> Date: Tue, 27 Dec 1994 17:02:09 GMT References: <1994Dec26.015609.1862@berkeley.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Dec26.015609.1862@berkeley.edu>, rtakahashi@berkeley.edu (Rodrigo Takahashi) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. -- Nadine Karlsson Practical Peripherals 14.4 @ 28,800 bps "Extraordinary claims require extraordinary spectra." From fmartinez@u-tokyo.ac.jp Wed Dec 28 08:26:09 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!fmartinez From: fmartinez@u-tokyo.ac.jp (Freya Martínez) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec28.082609.3502@u-tokyo.ac.jp> Date: Wed, 28 Dec 1994 08:26:09 GMT References: <1994Dec26.015609.1862@berkeley.edu> <1994Dec27.170209.1730@rwth-aachen.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Dec27.170209.1730@rwth-aachen.de>, nkarlsson@rwth-aachen.de (Nadine Karlsson) writes: > That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. 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. -- Freya Martínez Practical Peripherals 14.4 @ 14,400 bps "Extraordinary claims require extraordinary spectra."