From dreyes@cern.ch Wed Feb 08 19:41:48 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cern!dreyes From: dreyes@cern.ch (Dmitri Reyes) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb08.194148.5281@cern.ch> Date: Wed, 08 Feb 1995 19:41:48 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- === Dmitri Reyes === Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva "We don't sign stars. We build them." From rsokolov@inria.fr Thu Feb 09 08:51:48 1995 Path: ashpoly!cascade!bigsur!inria!rsokolov From: rsokolov@inria.fr (Renata Sokolov) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb09.085148.6254@inria.fr> Date: Thu, 09 Feb 1995 08:51:48 GMT References: <1995Feb08.194148.5281@cern.ch> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Feb08.194148.5281@cern.ch>, dreyes@cern.ch (Dmitri Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Renata Sokolov *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From ckim@tum.de Fri Feb 10 17:44:48 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!tum!ckim From: ckim@tum.de (Camila Kim) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb10.174448.9803@tum.de> Date: Fri, 10 Feb 1995 17:44:48 GMT References: <1995Feb08.194148.5281@cern.ch> <1995Feb09.085148.6254@inria.fr> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Feb09.085148.6254@inria.fr>, rsokolov@inria.fr (Renata Sokolov) writes: > 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. You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. -- Camila Kim Tape trading list upon request. SASE required for international mail. From skowalski@cern.ch Sat Feb 11 04:41:48 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cern!skowalski From: skowalski@cern.ch (Seo-yeon Kowalski) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb11.044148.1013@cern.ch> Date: Sat, 11 Feb 1995 04:41:48 GMT References: <1995Feb08.194148.5281@cern.ch> <1995Feb09.085148.6254@inria.fr> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Feb09.085148.6254@inria.fr>, rsokolov@inria.fr (Renata Sokolov) writes: > 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Seo-yeon Kowalski Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva. ------------------------------------------------------------