From cokonkwo@berkeley.edu Thu Jun 01 15:30:43 1995 Path: ashpoly!cascade!bigsur!berkeley!cokonkwo From: cokonkwo@berkeley.edu (Callum Okonkwo) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun01.153043.8131@berkeley.edu> Date: Thu, 01 Jun 1995 15:30:43 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] 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. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- === Callum Okonkwo === Dept of Electrical Engineering, UC Berkeley Department of EECS "The carrier frequency does not drift by accident." From slindqvist@cmu.edu Sat Jun 03 03:56:43 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!slindqvist From: slindqvist@cmu.edu (Sergei Lindqvist) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun03.035643.5700@cmu.edu> Date: Sat, 03 Jun 1995 03:56:43 GMT References: <1995Jun01.153043.8131@berkeley.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Jun01.153043.8131@berkeley.edu>, cokonkwo@berkeley.edu (Callum Okonkwo) 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. PGP Public key available via finger or upon request. -- === Sergei Lindqvist === Dept of Electrical Engineering, Carnegie Mellon University School of CS "Hardware is temporary. The signal survives." From ehughes@panix.com Sat Jun 03 22:27:43 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!ehughes From: ehughes@panix.com (Élodie Hughes) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun03.222743.8288@panix.com> Date: Sat, 03 Jun 1995 22:27:43 GMT References: <1995Jun01.153043.8131@berkeley.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jun01.153043.8131@berkeley.edu>, cokonkwo@berkeley.edu (Callum Okonkwo) 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. That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. -- Élodie Hughes Opinions expressed are solely my own and not those of Public Access Unix of New York. ------------------------------------------------------------ From agarcia@cam.ac.uk Tue Jun 06 00:36:43 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!agarcia From: agarcia@cam.ac.uk (Anja García) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun06.003643.6565@cam.ac.uk> Date: Tue, 06 Jun 1995 00:36:43 GMT References: <1995Jun01.153043.8131@berkeley.edu> <1995Jun03.035643.5700@cmu.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun03.035643.5700@cmu.edu>, slindqvist@cmu.edu (Sergei Lindqvist) writes: > Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Anja García | agarcia@cam.ac.uk PGP Key fingerprint: 0203 F024 6D01 D082 "Keep the channels open."