Date:         Tue, 15 Aug 2006 14:45:15 -0700
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         David Breneman <[log in to unmask]>
Subject:      Re: NASA
Comments: To: Association for Recorded Sound Discussion List <[log in to unmask]>
In-Reply-To:  <006e01c6c0ae$dcdea8a0$6901a8c0@TOMOFFICE>
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--- Tom Fine <[log in to unmask]> wrote:

> Richard Hess, who I
> believe is on vacation, knows more 
> about the details of this because he is somewhat expert on
> instrumentation formats. But I'll take a 
> stab. I think the video was high-resolution, slow-scan as it was
> transmitted and recorded. In other 
> words, an hour-long spacewalk might take all night to transmit and
> record. Apparently, this format 
> was re-modulated to NTSC to feed the networks. Now what I'm not
> clear on, was there a simultaneous 
> low-quality feed coming live from the moon? 

The moon walk was broadcast live.  The signal from the moon
was 320 lines, progressive scan, 10 frames per second. *Not*
high resolution by any standard (newer than 1934) but a
higher resolution than was seen by anybody except the
technicians at the three Deep Space Tracking Network 
stations.  The conversion process (shooting a long-
persistence monitor with an NTSC video camera) produced
a lot of smearing and reduced the contrast range 
significantly, so the already low-res picture was
even lower-res by the time anyone (except those few
engineers) saw it.  The reason it was sent as a slow
scan signal was because there wasn't enough bandwidth
to reliably transmit the necessary instrument
telemetry and an NTSC television signal on the
bandwidth available.




David Breneman         [log in to unmask]

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