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mrz
08-08-03, 05:09
Space talk

Question

When Yuri Gagarin orbited the Earth and when Apollo 11 landed on the moon, the TV broadcasts had very poor quality pictures and sound. Last week, I saw a broadcast from The International Space Station. Video from space is now very clear and sharp, yet the audio is as bad as in 1960s. Why has one improved but not the other?
Harry Hutchinson , Bradford, West Yorkshire, UK

Answer

The problems of deciphering the speech from astronauts have very little to do with the broadcast qualities of the signals arriving from space. As the questioner says, these have improved immeasurably since Yuri Gagarin orbited Earth in 1961 and Neil Armstrong landed on the moon in 1969.

The problem actually arises from the microphones the astronauts use to speak to Mission Control. High-quality microphones are heavy, and weight is always at a premium on space flights. Sound quality for TV viewers is one of NASA's lower priorities. So light, cheap wireless microphones are installed in astronauts' equipment. Their wireless speech messages travel as an FM signal to the space station or shuttle communicator and then by radio and satellite to the Earth, which obviously degrades the signal further. But as long as Mission Control understands the information, that is considered good enough.

Astronauts do train to use the microphones in a way that makes their speech intelligible, but in the heat of the moment their voices can become garbled.
Stephanie Richards , Bournemouth, Dorset, UK


http://www.newscientist.com/lastword/article.jsp?id=lw1025

Heh ik weet niet maar ik kijk ook langzaamaan beetje anders tegen science fiction aan, best grappig hoe sommige reruns ineens heel anders overkomen.

Maarten
08-08-03, 07:24
Maar het verhaal? Het is veel grotere larie dan op maroc.nl!
(het is hier trouwens in twee jaar tijd véel beter geworden..)

Maar wat een flauwe kul! De geluidskwaliteit vanuit de ruimte zou slechter zijn vanwege de microfoons.. Nou, ik kocht hier al jaren geleden een piezzo-micje voor 2 piek of zo! Perfect geluid hoor.
Die zitten ook in telefoons. En telefoon klinkt misschien niet optimaal, maar dat komt omdat ze alle hoge en lage tonen er uit filteren, en er maar een hele smalle bandbreedte overblijft.
Interviews met zo'n microfoontje klinken prima.