From bramirez@berkeley.edu Sun Dec 03 09:40:57 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!berkeley!bramirez From: bramirez@berkeley.edu (Bruno Ramírez) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec03.094057.1722@berkeley.edu> Date: Sun, 03 Dec 1995 09:40:57 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. MATLAB script available upon request via email. -- Bruno Ramírez Tape trading list upon request. SASE required for international mail. From imuller@rwth-aachen.de Sun Dec 03 19:50:57 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!imuller From: imuller@rwth-aachen.de (Ines Müller) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec03.195057.4257@rwth-aachen.de> Date: Sun, 03 Dec 1995 19:50:57 GMT References: <1995Dec03.094057.1722@berkeley.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Dec03.094057.1722@berkeley.edu>, bramirez@berkeley.edu (Bruno Ramírez) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Ines Müller "When every node is whole, the channel opens." 486DX2/66 (Linux 1.2.13) / NEXTSTEP 3.3 From mrodriguez@titech.ac.jp Mon Dec 04 18:21:57 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!mrodriguez From: mrodriguez@titech.ac.jp (Mateo Rodríguez) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec04.182157.6293@titech.ac.jp> Date: Mon, 04 Dec 1995 18:21:57 GMT References: <1995Dec03.094057.1722@berkeley.edu> <1995Dec03.195057.4257@rwth-aachen.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Dec03.195057.4257@rwth-aachen.de>, imuller@rwth-aachen.de (Ines Müller) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Mateo Rodríguez "There are 14 nodes and only 10 countries. Count again." 486DX2/66 (Linux 1.2.13) / System 7.5.1