Re: hubble

John Ingham (johningh@tafe.sa.edu.au)
Mon, 17 Feb 1997 12:45:14 +0930


In commenting about the Hubble Shuttle mission at
http://netra.exploratorium.edu/hubble/
Adrian said...

>Well, I saw a series of "live" stills with a couple of minutes between each
>frame! Not quite "live video". It was interesting to see though - and
>impressive in its own way. Good RealAudio of course also.

Over a 28,800 modem I saw quite reasonable quality color video running at
about 1 frame every 2 seconds or so. Of course the picture content was
pretty static only changing every several minutes, except when they were
running shots from Mission Control and during the space walks when there
was continuous movement available. But at other times, by looking closely
at the static shot I could tell that I still had new frames incoming every
2 seconds by observing small changes in the noise pattern in each frame.

The RealAudio via my web browser required too wide a bandwidth (60kbs) for
my connection, so I tried the RealAudio "helper" version; unfortunately all
I got was "Server not reachable" messages.

So I ran CU-SeeMe concurrently with my web browser and connected to one of
the NASA reflectors. By closing all video windows I was able to receive
the audio from CU-SeeMe and the color video via the web browser. When
there was audio to be had, the frame rate of the video halved (ie 1 frame
every 4 seconds or so) but there was NO picture break-up of any sort.

Over-all I thought that it was remarkable that I got as good results as I
did. If only CU-SeeMe could be made to work as well as this combination!

John Ingham
Supervisor, Technical Operations, TLC (Tele-Learning Consortium)
Adelaide Institute of TAFE (Training and Further Education)
GPO Box 1872 Adelaide South Australia 5001
Ph: +61 8 8207 8550 Fax: +61 8 8207 8552
Email: johningh@tafe.sa.edu.au
Web Site: http://www.tafe.sa.edu.au/video-conf/
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