From tjohansson@mit.edu Wed Mar 01 06:40:21 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!tjohansson From: tjohansson@mit.edu (Takeshi Johansson) Newsgroups: comp.dsp Subject: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar01.064021.7781@mit.edu> Date: Wed, 01 Mar 1995 06:40:21 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 How the 14 ASCII characters per node are encoded into the record groove. The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20). Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization. Has anyone encountered bit errors in their decoded text? The Golay decoder corrects up to 3 bit errors per 24-bit codeword. -- === Takeshi Johansson === Dept of Electrical Engineering, Massachusetts Institute of Technology "The hatch is open. Is anyone listening?" From rcampbell@uni-hamburg.de Thu Mar 02 21:39:21 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!uni-hamburg!rcampbell From: rcampbell@uni-hamburg.de (Raj Campbell) Newsgroups: comp.dsp Subject: Re: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar02.213921.3349@uni-hamburg.de> Date: Thu, 02 Mar 1995 21:39:21 GMT References: <1995Mar01.064021.7781@mit.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Mar01.064021.7781@mit.edu>, tjohansson@mit.edu (Takeshi Johansson) writes: > How the 14 ASCII characters per node are encoded into the record groove. The song wasn't written around the lyrics. The lyrics were timed to match the telemetry packet duration! -- Raj Campbell Opinions expressed are solely my own and not those of Universität Hamburg Fachbereich Informatik. ------------------------------------------------------------ From tfischer@delphi.com Sat Mar 04 00:26:21 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!tfischer From: tfischer@delphi.com (Tyler Fischer) Newsgroups: comp.dsp Subject: Re: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar04.002621.9855@delphi.com> Date: Sat, 04 Mar 1995 00:26:21 GMT References: <1995Mar01.064021.7781@mit.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Mar01.064021.7781@mit.edu>, tjohansson@mit.edu (Takeshi Johansson) writes: > How the 14 ASCII characters per node are encoded into the record groove. > The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20). The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code. -- Tyler Fischer *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From mduarte@hanse.de Sat Mar 04 03:43:21 1995 Path: ashpoly!cascade!transat!ukc!fennimore!hanse!mduarte From: mduarte@hanse.de (Mateo Duarte) Newsgroups: comp.dsp Subject: Re: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar04.034321.6618@hanse.de> Date: Sat, 04 Mar 1995 03:43:21 GMT References: <1995Mar01.064021.7781@mit.edu> <1995Mar02.213921.3349@uni-hamburg.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar02.213921.3349@uni-hamburg.de>, rcampbell@uni-hamburg.de (Raj Campbell) writes: > The song wasn't written around the lyrics. The lyrics were timed to match the telemetry packet duration! On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text. -- Mateo Duarte "They will send a copy in my place." Decstation 5000/200 / SunOS 4.1.4