From agarcia@mindspring.com Mon Jun 17 07:02:45 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!agarcia From: agarcia@mindspring.com (Astrid García) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun17.070245.9519@mindspring.com> Date: Mon, 17 Jun 1996 07:02:45 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 10 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. 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. -- Astrid García Tape trading list upon request. SASE required for international mail. From nsato@ox.ac.uk Tue Jun 18 04:53:45 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!ox!nsato From: nsato@ox.ac.uk (Nadia Sato) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun18.045345.8538@ox.ac.uk> Date: Tue, 18 Jun 1996 04:53:45 GMT References: <1996Jun17.070245.9519@mindspring.com> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Jun17.070245.9519@mindspring.com>, agarcia@mindspring.com (Astrid García) 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. -- Nadia Sato *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From tchoi@u-tokyo.ac.jp Wed Jun 19 07:23:45 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!tchoi From: tchoi@u-tokyo.ac.jp (Tyler Choi) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun19.072345.3243@u-tokyo.ac.jp> Date: Wed, 19 Jun 1996 07:23:45 GMT References: <1996Jun17.070245.9519@mindspring.com> <1996Jun18.045345.8538@ox.ac.uk> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Jun18.045345.8538@ox.ac.uk>, nsato@ox.ac.uk (Nadia Sato) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. PGP Public key available via finger or upon request. -- Tyler Choi *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From sjohansson@ox.ac.uk Thu Jun 20 21:35:45 1996 Path: ashpoly!cascade!brgate!saturno!ox!sjohansson From: sjohansson@ox.ac.uk (Steve Johansson) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun20.213545.6690@ox.ac.uk> Date: Thu, 20 Jun 1996 21:35:45 GMT References: <1996Jun17.070245.9519@mindspring.com> <1996Jun18.045345.8538@ox.ac.uk> <1996Jun19.072345.3243@u-tokyo.ac.jp> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Jun19.072345.3243@u-tokyo.ac.jp>, tchoi@u-tokyo.ac.jp (Tyler Choi) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Steve Johansson *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From bcampbell@delphi.com Sat Jun 22 01:35:45 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!delphi!bcampbell From: bcampbell@delphi.com (Bastien Campbell) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun22.013545.2103@delphi.com> Date: Sat, 22 Jun 1996 01:35:45 GMT References: <1996Jun17.070245.9519@mindspring.com> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Jun17.070245.9519@mindspring.com>, agarcia@mindspring.com (Astrid García) 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Bastien Campbell "A soul is not exclusive to biology." Macintosh IIfx / NEXTSTEP 3.3