From spark@hanse.de Fri Dec 15 23:49:23 1995 Path: ashpoly!cascade!mxgate!coyoacan!hanse!spark From: spark@hanse.de (Sergei Park) Newsgroups: comp.dsp Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec15.234923.2718@hanse.de> Date: Fri, 15 Dec 1995 23:49:23 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 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. -- Sergei Park Tape trading list upon request. SASE required for international mail. From tgonzalez@panix.com Sat Dec 16 13:56:23 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!tgonzalez From: tgonzalez@panix.com (Takeshi González) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec16.135623.1294@panix.com> Date: Sat, 16 Dec 1995 13:56:23 GMT References: <1995Dec15.234923.2718@hanse.de> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec15.234923.2718@hanse.de>, spark@hanse.de (Sergei Park) 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. -- Takeshi González "In theory there is no difference between theory and practice." Decstation 5000/200 / FreeBSD 2.1