Question about radio signals and seti

Message boards : SETI@home Science : Question about radio signals and seti
Message board moderation

To post messages, you must log in.

Previous · 1 · 2

AuthorMessage
Profile Andrew Sanchez
Avatar

Send message
Joined: 10 Apr 14
Posts: 69
Credit: 471,907
RAC: 0
United States
Message 1513723 - Posted: 8 May 2014, 18:13:32 UTC - in response to Message 1513605.  

Hello Yo:) Thanks for the links. I read over the links and found them interesting but I don't believe that i have enough physics yet to comment on either article (that will be changing over the next couple years). Every time i started to believe i understood Messerschmitt's thesis for the article i started to doubt myself. Is he saying that we should be looking for a large bandwidth pulse because the larger the bandwidth the less energy required to transmit the signal above the Shannon limit, or did i miss the point of the article entirely? My limited understanding of the article may be completely off that's why I'm asking.
ID: 1513723 · Report as offensive
yo2013
Avatar

Send message
Joined: 9 Mar 14
Posts: 173
Credit: 50,837
RAC: 0
Spain
Message 1514114 - Posted: 9 May 2014, 17:12:32 UTC - in response to Message 1513723.  
Last modified: 9 May 2014, 17:13:30 UTC

Hi Andrew :)

Well, I'm not an electrical engineer, but I think what Messerschmitt says is:

- If you decrease the bandwidth, design complexity and energy requirements increase. So it's better to use broad bandwidths.

- Nevertheless, above a sufficiently high bandwith, energy requirements don't change. This is good, because the atmosphere and the interstellar medium prevent us from using the whole radio spectrum. For example, the atmosphere is opaque to certain frequencies.

So, signals must be broadband. This also has the additional benefit that interference from TV, radio stations, etc. are less likely, because they are narrowband.

Hope it helps.
ID: 1514114 · Report as offensive
Profile Andrew Sanchez
Avatar

Send message
Joined: 10 Apr 14
Posts: 69
Credit: 471,907
RAC: 0
United States
Message 1516278 - Posted: 14 May 2014, 23:58:06 UTC - in response to Message 1514114.  

Thanks Yo! You said,
"- Nevertheless, above a sufficiently high bandwith, energy requirements don't change. This is good, because the atmosphere and the interstellar medium prevent us from using the whole radio spectrum. For example, the atmosphere is opaque to certain frequencies."
See, i missed that point entirely; that's why i asked. Thanks for summarizing that for me, i'm glad everyone here is so helpful :)
ID: 1516278 · Report as offensive
anniet
Volunteer tester
Avatar

Send message
Joined: 2 Feb 14
Posts: 7105
Credit: 1,577,368
RAC: 75
Zambia
Message 1516288 - Posted: 15 May 2014, 0:20:33 UTC - in response to Message 1516278.  

Thanks Yo! You said,
"- Nevertheless, above a sufficiently high bandwith, energy requirements don't change. This is good, because the atmosphere and the interstellar medium prevent us from using the whole radio spectrum. For example, the atmosphere is opaque to certain frequencies."
See, i missed that point entirely; that's why i asked. Thanks for summarizing that for me, i'm glad everyone here is so helpful :)


I'm not much use, but thank you for the tinfoil tip :)
ID: 1516288 · Report as offensive
Profile Andrew Sanchez
Avatar

Send message
Joined: 10 Apr 14
Posts: 69
Credit: 471,907
RAC: 0
United States
Message 1516378 - Posted: 15 May 2014, 5:07:28 UTC - in response to Message 1516288.  

Haha! No problem. Foil is also good for keeping the NSA from reading your thoughts!;)
ID: 1516378 · Report as offensive
Ian_Flaming

Send message
Joined: 10 Feb 10
Posts: 1
Credit: 82,626
RAC: 0
United Kingdom
Message 1524181 - Posted: 3 Jun 2014, 22:24:12 UTC

Hi there!

I am glad to be able to offer my computer to assist in the number crunching for the Seti project.
It's fascinating to view the computation process in dynamic 3-D graphics. I see that the display includes a read-out displaying data on transmitted power/type of transmission and a 'score'.
It would be even more fascinating if I could make sense of the data! Is there a chart/publication somewhere that explains all this in more detail? I would especially like to know what kind of numbers are likely to get the professional Seti guys excited - for example, what would constitute a good 'score' number as far as a possible ETI 'hit' is concerned?
If I was able to do a bit of simple analysis myself, this would certainly further my interest in Seti.
ID: 1524181 · Report as offensive
Profile ML1
Volunteer moderator
Volunteer tester

Send message
Joined: 25 Nov 01
Posts: 20437
Credit: 7,508,002
RAC: 20
United Kingdom
Message 1524185 - Posted: 3 Jun 2014, 22:44:45 UTC - in response to Message 1524181.  

... It would be even more fascinating if I could make sense of the data! ...

The obvious place to start is:

How SETI@home works


Welcome to the great search!

Keep searchin',
Martin
See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)
ID: 1524185 · Report as offensive
Profile Julie
Volunteer moderator
Volunteer tester
Avatar

Send message
Joined: 28 Oct 09
Posts: 34054
Credit: 18,883,157
RAC: 18
Belgium
Message 1524186 - Posted: 3 Jun 2014, 22:48:25 UTC

I second that wholeheartedly. Welcome to the boards Ian.
rOZZ
Music
Pictures
ID: 1524186 · Report as offensive
Profile Lynn Special Project $75 donor
Volunteer tester
Avatar

Send message
Joined: 20 Nov 00
Posts: 14162
Credit: 79,603,650
RAC: 123
United States
Message 1524187 - Posted: 3 Jun 2014, 22:48:47 UTC - in response to Message 1524181.  

Welcome Ian_Flaming to the SETI Forums!
ID: 1524187 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 3387
Credit: 4,182,900
RAC: 10
United States
Message 1524259 - Posted: 4 Jun 2014, 3:40:47 UTC

I used to watch the screen saver for hours sometimes to the point where I was sure I was seeing patterns. But now I doubt that anything significant will be detected by looking at those images. It will take a strong computer program to find hidden transmissions if they exist.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1524259 · Report as offensive
Profile Julie
Volunteer moderator
Volunteer tester
Avatar

Send message
Joined: 28 Oct 09
Posts: 34054
Credit: 18,883,157
RAC: 18
Belgium
Message 1524442 - Posted: 4 Jun 2014, 16:35:06 UTC

The images are representative, didn't know that either.
rOZZ
Music
Pictures
ID: 1524442 · Report as offensive
Previous · 1 · 2

Message boards : SETI@home Science : Question about radio signals and seti


 
©2024 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.