Re: [ARSCLIST] NASA

["Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>]

At 05:45 PM 8/15/2006, David Breneman wrote:

> 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.

Apparently this is getting wide coverage. My wife saw it on our local 
Toronto news channel as we got home from vacation tonight.

The challenge will be WHEN the tapes are found what can be done with 
them. NASA has to close the lab that can still play the tapes. People 
within the Gov't have their hands out to hold onto this gear.

Lots of people can play 14-track IRIG tapes (which these are). I 
think these ran at 120 or 240 in/s - the PDF says, IIRC.

So, if the tapes are at all playable -- and I suspect they are -- the 
signals can be recovered. The next step is demodulating them in such 
a way that we can get them reliably into rasters. Then the rasters 
have to be replicated and played out. So 10 fps, would be actually 
played at 9.99 or something like that to get up to the 29.97 rate of NTSC.

The easiest (but not the best) thing would be to triple each frame. 
The best thing would be to do motion interpolation between "key" 
frames as broadcast and then create the intermediate frames based on 
linear (if nothing better) interpolation of moving objects' positions.

The 320 line detail is all we'll get, but it should be much better 
than the CRT standards conversion done in 1969.

The still photos are much higher resolution (Hassleblad and Nikon 
cameras were used in that era of NASA, IIRC).

I am in no rush to set up for 14-track 1" IRIG but it is on my radar 
screen. I successfully completed my first FM 7-track 1/2-inch IRIG 
transfer of seismic data. It was a real learning experience. The 
client had searched for months for someone to do this and he was very 
complimentary in telling others of my work.

I think the big problem here is FINDING the tapes. I think many 
people could handle them. I would love to, but I suspect that someone 
in the DC area could probably do it.

One concern is the jitter. The Ampex machines had a very interesting 
low-jitter tape path while most instrumentation recorders look more 
like audio tape players and don't have the time base accuracy of the 
Ampex machines originally used for the recording. On the other hand, 
I suspect that the slow-scan video doesn't need something like 10 ps 
time base accuracy.

Cheers,

Richard


Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.