From dgirard@earthlink.net Tue Dec 20 10:34:06 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!dgirard From: dgirard@earthlink.net (Dave Girard) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Dec20.103406.8449@earthlink.net> Date: Tue, 20 Dec 1994 10:34:06 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. MATLAB script available upon request via email. -- Dave Girard "Hold for relay." Commodore Amiga 500 (1MB OCS) / System 7.5.1 From mlopez@cmu.edu Wed Dec 21 06:27:06 1994 Path: ashpoly!cascade!transat!ukc!fennimore!cmu!mlopez From: mlopez@cmu.edu (Min-jun López) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Dec21.062706.3046@cmu.edu> Date: Wed, 21 Dec 1994 06:27:06 GMT References: <1994Dec20.103406.8449@earthlink.net> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Dec20.103406.8449@earthlink.net>, dgirard@earthlink.net (Dave Girard) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Min-jun López Tape trading list upon request. SASE required for international mail. From mpetrov@mit.edu Wed Dec 21 15:50:06 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!mpetrov From: mpetrov@mit.edu (Marta Petrov) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Dec21.155006.2481@mit.edu> Date: Wed, 21 Dec 1994 15:50:06 GMT References: <1994Dec20.103406.8449@earthlink.net> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994Dec20.103406.8449@earthlink.net>, dgirard@earthlink.net (Dave Girard) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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. -- Marta Petrov *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0