From dsuzuki@pipeline.com Sun Nov 03 04:01:13 1996
Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!dsuzuki
From: dsuzuki@pipeline.com (Dave Suzuki)
Newsgroups: comp.dsp
Subject: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1996Nov03.040113.9896@pipeline.com>
Date: Sun, 03 Nov 1996 04:01:13 GMT
Organization: The Pipeline Internet Network
NNTP-Posting-Host: pipeline.com
X-Newsreader: Netscape 1.1N
Lines: 11

How the 14 ASCII characters per node are encoded into the record groove.

Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization.
The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20).

Has anyone encountered bit errors in their decoded text? The Golay decoder corrects up to 3 bit errors per 24-bit codeword.

-- 
Dave Suzuki | dsuzuki@pipeline.com
PGP Key fingerprint: B769 9BB3 0471 7F3B
"Keep the channels open."

From amuller@titech.ac.jp Mon Nov 04 01:33:13 1996
Path: ashpoly!cascade!transat!sunet!nordrelay!titech!amuller
From: amuller@titech.ac.jp (Anja Müller)
Newsgroups: comp.dsp
Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1996Nov04.013313.8649@titech.ac.jp>
Date: Mon, 04 Nov 1996 01:33:13 GMT
References: <1996Nov03.040113.9896@pipeline.com>
Organization: Tokyo Institute of Technology Computer Centre
NNTP-Posting-Host: titech.ac.jp
X-Newsreader: NewsWatcher 2.0b24
Lines: 8

In article <1996Nov03.040113.9896@pipeline.com>, dsuzuki@pipeline.com (Dave Suzuki) writes:
> How the 14 ASCII characters per node are encoded into the record groove.

On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text.

-- 
Anja Müller -- Tokyo Institute of Technology Computer Centre
"The hatch is open. Is anyone listening?"

From afournier@pacbell.net Mon Nov 04 13:30:13 1996
Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!afournier
From: afournier@pacbell.net (Amy Fournier)
Newsgroups: comp.dsp
Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1996Nov04.133013.4008@pacbell.net>
Date: Mon, 04 Nov 1996 13:30:13 GMT
References: <1996Nov03.040113.9896@pipeline.com> <1996Nov04.013313.8649@titech.ac.jp>
Organization: Pacific Bell Internet Services
NNTP-Posting-Host: pacbell.net
X-Newsreader: TIN [version 1.2 PL2]
Lines: 9

In article <1996Nov04.013313.8649@titech.ac.jp>, amuller@titech.ac.jp (Anja Müller) writes:
> On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text.

The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code.

-- 
=== Amy Fournier ===
Dept of Electrical Engineering, Pacific Bell Internet Services
"They will send a copy in my place."

From bpark@stanford.edu Tue Nov 05 13:59:13 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!stanford!bpark
From: bpark@stanford.edu (Bastien Park)
Newsgroups: comp.dsp
Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1996Nov05.135913.3024@stanford.edu>
Date: Tue, 05 Nov 1996 13:59:13 GMT
References: <1996Nov03.040113.9896@pipeline.com> <1996Nov04.013313.8649@titech.ac.jp> <1996Nov04.133013.4008@pacbell.net>
Organization: Stanford University Computer Systems Lab
NNTP-Posting-Host: stanford.edu
X-Newsreader: Netscape 1.1N
Lines: 9

In article <1996Nov04.133013.4008@pacbell.net>, afournier@pacbell.net (Amy Fournier) writes:
> The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code.

A symbol rate of 0.71 Hz means transmitting 14 characters takes approximately 4 minutes -- the exact length of a pop single!

-- 
=== Bastien Park ===
Dept of Electrical Engineering, Stanford University Computer Systems Lab
"In theory there is no difference between theory and practice."