Test signal

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Rasputin42
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Message 1691351 - Posted: 14 Jun 2015, 21:14:23 UTC

Has anyone tried to use a signal from any space probe launched from earth to verify the detection system?
Due to a lack of an ET signal, this seems to be them best approach to test, if all the efforts have a chance of working.
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Profile Bob DeWoody
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Message 1691393 - Posted: 15 Jun 2015, 0:25:13 UTC
Last modified: 15 Jun 2015, 0:25:35 UTC

They are still communicating with at least one of the voyagers, but it's transmitter is aimed at earth. I doubt that an omni-directional signal could be distinguished from the background noise.
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Rasputin42
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Message 1691575 - Posted: 15 Jun 2015, 10:10:29 UTC

So, if they can't even pick up that signal with seti@home, which is at a known position pointing at earth and still very close , there is no way, they can detect ET signals.
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rob smithProject Donor
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Message 1691599 - Posted: 15 Jun 2015, 11:20:57 UTC

It is not as simple as you assume.
The radio signals are recorded using equipment that is regular use for other branches of radio astronomy so we know they are working.
The (initial) purpose is to detect locations and frequency bands that are repeating over a long term (years not hours). There is no attempt to decode the signals. At some time in the future, there may be attempts to decode suitable signals, but that is currently a long way off.
Bob Smith
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Profile William Rothamel
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Message 1691625 - Posted: 15 Jun 2015, 13:14:07 UTC - in response to Message 1691575.  
Last modified: 15 Jun 2015, 13:16:15 UTC

The space probes use very low power; the reason that we can pick them up is because they are beamed (focused) back at Earth and we know where to aim our receiving antennae (dishes).Also they are extremely close to Earth in cosmic terms.

I have long felt that we could only detect a focused beam (randomly slewed around) of very high power. I say this because i suspect that such a purposeful communication would be coming from many many lightyears away.

Hopefully such a message would not be stored away and then discarded since it was not repeating nor persistent some long time later. I think that with todays super computers each reception that correlates above the noise and is from a direction with no known radio source should be analyzed further on the fly before it is flagged as interesting.

50 tears of listening seems to indicate that the hope of eaves dropping on another nearby civilization is a failed strategy.
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Profile Julie
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Message 1691671 - Posted: 15 Jun 2015, 15:03:44 UTC
Last modified: 15 Jun 2015, 15:09:01 UTC

On the WOW signal:

Zowel de lengte van het signaal (72 seconden) als de gedurende de eerste helft van het signaal stijgende en daarna dalende intensiteit, komt overeen met het te verwachten patroon voor een signaal van buitenaardse oorsprong.


Source: Dutch Wikipedia

http://nl.wikipedia.org/wiki/Wow!-signaal

It says that the length, the inclination and afterwards decreasing intensity of the message shows a pattern that we can expect from ETI.
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Profile Gordon Lowe
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Message 1692004 - Posted: 16 Jun 2015, 4:05:25 UTC - in response to Message 1691625.  

Hopefully such a message would not be stored away and then discarded since it was not repeating nor persistent some long time later. I think that with todays super computers each reception that correlates above the noise and is from a direction with no known radio source should be analyzed further on the fly before it is flagged as interesting.


I agree. Too bad they didn't save stuff like that in the Wow! days. :~(
The mind is a weird and mysterious place
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Profile River Song
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Message 1707787 - Posted: 2 Aug 2015, 18:35:06 UTC - in response to Message 1691625.  

There is one other reason, possibly unaware of by a few, that those very low power weak signals from, say, Voyager can be detected by the DSN: The signals do not have to be above the thermal noise floor to be detected. Since the transmitted signals are repetitive, i.e., data streams repeated over and over, rather than not, the receivers can detect them 20 dB or more below the noise floor by integrating over time.
River Song (aka Linda Latte on planet Earth)
"Happy I-Phone girl on the GO GO GO"
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Message boards : SETI@home Science : Test signal


 
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