From dsouza@utexas.edu Fri Apr 07 06:14:20 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!dsouza From: dsouza@utexas.edu (Diego Souza) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr07.061420.8009@utexas.edu> Date: Fri, 07 Apr 1995 06:14:20 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- Diego Souza SupraFAXModem 28.8 @ ISDN 64k bps "Do not worship the copy." From nfournier@clari.net Fri Apr 07 18:31:20 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!clari!nfournier From: nfournier@clari.net (Nadia Fournier) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr07.183120.2450@clari.net> Date: Fri, 07 Apr 1995 18:31:20 GMT References: <1995Apr07.061420.8009@utexas.edu> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Apr07.061420.8009@utexas.edu>, dsouza@utexas.edu (Diego Souza) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- Nadia Fournier Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------ From tkang@illinois.edu Sat Apr 08 05:48:20 1995 Path: ashpoly!cascade!mxgate!coyoacan!illinois!tkang From: tkang@illinois.edu (Tobias Kang) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr08.054820.9525@illinois.edu> Date: Sat, 08 Apr 1995 05:48:20 GMT References: <1995Apr07.061420.8009@utexas.edu> <1995Apr07.183120.2450@clari.net> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Apr07.183120.2450@clari.net>, nfournier@clari.net (Nadia Fournier) writes: > 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. PGP Public key available via finger or upon request. -- Tobias Kang Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------ From iramirez@pacbell.net Sun Apr 09 23:25:20 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!iramirez From: iramirez@pacbell.net (Ines Ramírez) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr09.232520.2230@pacbell.net> Date: Sun, 09 Apr 1995 23:25:20 GMT References: <1995Apr07.061420.8009@utexas.edu> <1995Apr07.183120.2450@clari.net> <1995Apr08.054820.9525@illinois.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Apr08.054820.9525@illinois.edu>, tkang@illinois.edu (Tobias Kang) 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. -- Ines Ramírez Tape trading list upon request. SASE required for international mail.