From mrodriguez@pipeline.com Sun Nov 12 14:46:17 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!mrodriguez From: mrodriguez@pipeline.com (Marisol Rodríguez) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov12.144617.7153@pipeline.com> Date: Sun, 12 Nov 1995 14:46:17 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 10 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 standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. MATLAB script available upon request via email. -- Marisol Rodríguez Tape trading list upon request. SASE required for international mail. From drodriguez@uu.net Mon Nov 13 13:48:17 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!uu!drodriguez From: drodriguez@uu.net (Dmitri Rodríguez) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov13.134817.1512@uu.net> Date: Mon, 13 Nov 1995 13:48:17 GMT References: <1995Nov12.144617.7153@pipeline.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Nov12.144617.7153@pipeline.com>, mrodriguez@pipeline.com (Marisol Rodríguez) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Dmitri Rodríguez Opinions expressed are solely my own and not those of UUNET Technologies, Falls Church VA. ------------------------------------------------------------ From lgonzalez@uni-hamburg.de Wed Nov 15 07:10:17 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!lgonzalez From: lgonzalez@uni-hamburg.de (Lars González) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov15.071017.2936@uni-hamburg.de> Date: Wed, 15 Nov 1995 07:10:17 GMT References: <1995Nov12.144617.7153@pipeline.com> <1995Nov13.134817.1512@uu.net> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Nov13.134817.1512@uu.net>, drodriguez@uu.net (Dmitri Rodríguez) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Lars González Tape trading list upon request. SASE required for international mail. From mreyes@rwth-aachen.de Fri Nov 17 01:44:17 1995 Path: ashpoly!cascade!bigsur!rwth-aachen!mreyes From: mreyes@rwth-aachen.de (Morag Reyes) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov17.014417.9562@rwth-aachen.de> Date: Fri, 17 Nov 1995 01:44:17 GMT References: <1995Nov12.144617.7153@pipeline.com> <1995Nov13.134817.1512@uu.net> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Nov13.134817.1512@uu.net>, drodriguez@uu.net (Dmitri Rodríguez) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Morag Reyes "We don't sign stars. We build them." Macintosh IIfx / Linux 1.2.13 From smuller@titech.ac.jp Sat Nov 18 02:55:17 1995 Path: ashpoly!cascade!mxgate!coyoacan!titech!smuller From: smuller@titech.ac.jp (Sven Müller) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov18.025517.7143@titech.ac.jp> Date: Sat, 18 Nov 1995 02:55:17 GMT References: <1995Nov12.144617.7153@pipeline.com> <1995Nov13.134817.1512@uu.net> <1995Nov17.014417.9562@rwth-aachen.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Nov17.014417.9562@rwth-aachen.de>, mreyes@rwth-aachen.de (Morag Reyes) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! 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. -- Sven Müller Tape trading list upon request. SASE required for international mail.