From jgonzalez@u-tokyo.ac.jp Fri Nov 25 20:22:27 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!jgonzalez From: jgonzalez@u-tokyo.ac.jp (Ji-woo González) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov25.202227.4322@u-tokyo.ac.jp> Date: Fri, 25 Nov 1994 20:22:27 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. MATLAB script available upon request via email. -- Ji-woo González SupraFAXModem 28.8 @ 19,200 bps "5 sigma is a discovery. 7 is a question." From mgonzalez@stanford.edu Sat Nov 26 06:18:27 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!mgonzalez From: mgonzalez@stanford.edu (Mathieu González) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov26.061827.3969@stanford.edu> Date: Sat, 26 Nov 1994 06:18:27 GMT References: <1994Nov25.202227.4322@u-tokyo.ac.jp> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Nov25.202227.4322@u-tokyo.ac.jp>, jgonzalez@u-tokyo.ac.jp (Ji-woo González) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Mathieu González "5 sigma is a discovery. 7 is a question." Mac IIci / 68882 FPU / System 7.5.1 From rchoi@kth.se Sun Nov 27 17:09:27 1994 Path: ashpoly!cascade!brgate!saturno!kth!rchoi From: rchoi@kth.se (Renata Choi) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov27.170927.9819@kth.se> Date: Sun, 27 Nov 1994 17:09:27 GMT References: <1994Nov25.202227.4322@u-tokyo.ac.jp> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Nov25.202227.4322@u-tokyo.ac.jp>, jgonzalez@u-tokyo.ac.jp (Ji-woo González) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Renata Choi Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm. ------------------------------------------------------------ From kkowalski@purdue.edu Tue Nov 29 00:50:27 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!purdue!kkowalski From: kkowalski@purdue.edu (Katrin Kowalski) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov29.005027.5989@purdue.edu> Date: Tue, 29 Nov 1994 00:50:27 GMT References: <1994Nov25.202227.4322@u-tokyo.ac.jp> <1994Nov27.170927.9819@kth.se> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1994Nov27.170927.9819@kth.se>, rchoi@kth.se (Renata Choi) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Katrin Kowalski -- Purdue University Engineering Computer Network "The carrier frequency does not drift by accident." From aivanov@stanford.edu Wed Nov 30 06:38:27 1994 Path: ashpoly!cascade!brgate!saturno!stanford!aivanov From: aivanov@stanford.edu (Aiko Ivanov) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov30.063827.1140@stanford.edu> Date: Wed, 30 Nov 1994 06:38:27 GMT References: <1994Nov25.202227.4322@u-tokyo.ac.jp> <1994Nov27.170927.9819@kth.se> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Nov27.170927.9819@kth.se>, rchoi@kth.se (Renata Choi) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. -- Aiko Ivanov | aivanov@stanford.edu PGP Key fingerprint: E354 C287 B59F DDF4 "Keep the channels open."