From nkarlsson@cern.ch Fri May 05 16:31:01 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cern!nkarlsson From: nkarlsson@cern.ch (Nadine Karlsson) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May05.163101.2798@cern.ch> Date: Fri, 05 May 1995 16:31:01 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] 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 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. -- Nadine Karlsson *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From jperez@pipeline.com Sat May 06 00:01:01 1995 Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!jperez From: jperez@pipeline.com (Jens Pérez) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May06.000101.7572@pipeline.com> Date: Sat, 06 May 1995 00:01:01 GMT References: <1995May05.163101.2798@cern.ch> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995May05.163101.2798@cern.ch>, nkarlsson@cern.ch (Nadine Karlsson) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Top-posters will be placed in my ~/.killfile without notice. -- Jens Pérez Zyxel U-1496E @ 19,200 bps "5 sigma is a discovery. 7 is a question."