Hi,

I am looking for a detailed list/explanation of the steps SETI takes to verify the origins of a candidate signal. Automatic (done by the software before the signal is bought to the attention of the humans) or manual.

I tried finding something at the SETI site and on this board, but could not locate any resources.

TIA

Bharat

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Maybe this helps.

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Thanks Argos. I had already read that document. But it does not contain what I am looking for.

A couple of quotes from the declaration:

I was wondering how one would go about confirming that the signal is indeed generated by ET intelligence and not natural or human processes. Compare it with known satellite positions? Ask the military if they have an explanation for it? Is there a formal list of steps to be followed. Some kind of check list.

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An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says "You're all idiots", and pours two beers

I dont know the exact procedure, but I do know they :

1. record the signal and run through algorithms to determine if its artificial or suspect rather than say a natural source.
2. move the receiver off at least 5 degrees (?) from the source and retest
(this is to help identify if its terrestrial or not)
3. return the receiver to the coordinates to verify its still there
4. send coordinates to other (far away) facilities for secondary verification of signal.


edit for atrocai atrosi atroshus atr-- bad spelling.

Any chance of a source for that information?

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An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says "You're all idiots", and pours two beers

This information was from a documentary on SETI and the search for Life, as it aired on Discovery channel. Carl Sagan also wrote about this procedure in Contact. Yes, yes I know it was a work of fiction, but the Author being Carl Sagan, it's relevant.

Here is a link that describes moving the telescope off target and getting independant verification:


here is a link for a paper that also may shed some light, although it deals more with proving the signal defies entropy and is not terrerstrial.

edited to add links.

Further details: (my numbering format for ease of reading; text pulled from source. )

source: http://http://www.castfvg.it/zzz/comunicati/041012.htm

An ETI signal would leave some telltale signs, as location in a constrained region the sky, narrow bandwitdth, frequency variation due to planetary motion, modulation, etc.

I think this document discusses exactly what you´re looking for. Unfortunately, the full article is not readily available.

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Did you already browse the original SETI@HOME website? If not, here's a link to the FAQ. I remember there was a fairly extensive explanation on there, somewhere. The current SETI@HOME website is here, but I've never really looked into this newer version stuff.

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I can tell you how I proceed with falsification of any hits I get on my own SETI station.
A couple of links:

After detection protocol

What I'm Looking for

Falsification of latest hit

Of course this is all after the software has done its thing. If your interested in what my software does I can describe it to you.

Regards........ Jim (www.SETI.Net)

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James,

If you do receive a signal, Are you sure there aren't other SETI sites or at least project Argos members who could provide second source verification?


I'd like to know more about your software. Did you write it? What language? What methodology do you use to determine a given signal is artificial, non-terrestrial?

So far I have the only Argus station that actually works. There are only five SETI stations of any description on earth today (little known fact).

I wrote it all over the last 20 years. Its in Delphi 7. The software is looking for an intentional beacon directed toward our star that is narrow band (1-5 Hz)and constant. The software scans the waterhole while locked onto a specific DEC and Ra. Right now its tracking Delta Cancri (a star in Cancer).
It shifts its receiver down in frequency in time with the Doppler shift caused by the earths rotation and looks for signals that result in straight lines in the waterfall.

You can actually download the Spectrum Analyzer and run it on the streaming audio from my system to see it work on your own computer.

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Could you explain what it is you are looking for ?
Looking at this thus far all I see is a suspiciouse over active conspiracy therie advocate.
Am I wrong ?
Why do you say it that way ?... Is not enough that some program of detection is up and working. How and why do you think they are telling porkies ? I have not seen such. We have 0 signal.

JB -- thats pretty cool! Of course you'd have to hit the jackpot going star to star, but with such equipment, I guess thats all that is possible.

Maybe when we get some solid targets from the Kepler mission you could target those stars with possibly earthlike planets !

Very cool.

Everything I do and how I do it is on my web site.
(spell check is your friend)

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Jackpot indeed. The chances of me finding ET are so remote that winning the national lottery is a sure thing by comparison. Here is a link to my calculations of my stations addressable 'space' and the time it will take me to complete one pass through it. Some of the station parameters have changed from when I did this but the results will about triple the total space.

Yes I do plan to search the Kepler mission targets. My antenna has a good view of that part of the sky and so - why not.

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Verification software for SETI data is easy; it only needs a few lines of code.

Prose version:

Did you receive a genuine ET signal (y/n)?
if 'n' output 'correct!'
if 'y' output 'no you didn't'

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If you would like to watch a real time falsification process click on what I am seeing right now.
Rijl al Awwa
Right now this signal looks like a good candidate. You can see the steps I have taken so far to prove it is not ET.
Regards.... Jim

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Thanks a lot for the responses and links.

I would need a little time to go through all the links mentioned here. I will probably get back with more questions after I am done.

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An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says "You're all idiots", and pours two beers

Its not clear if this was directed at me.

If this looks like the work of a HB of some kind to you, then it's my fault for not phrasing my questions in a better way. I am mostly on the other side of the fence.

My motives are twofold. First, satisfy my own curiosity regarding SETI. Second, get an example of the scientific rigor needed to prove ETI. An example for the maxim "Extraordinary claims need extraordinary proof."

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An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says "You're all idiots", and pours two beers

Then we are in agreement. Thanks for the explanation...
As no signal has passed the test. We have a zero file of contact signals to work with. From this startling revelation we can deduce that...
/a We are not looking for the right thing. or...
/b Time and distance are against this ever changing... or
/c No such thing is possible. and this topic has been around the block a few times already. My truth on this is that I am pleased they are looking at all.

Bottom line: you can´t fake an ET signal from the surface of the Earth. Gotta have access to deep space, something that only the governments of the USA and Russia are able to.

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Well, ESA and JAXA have also demonstrated operation of spacecraft beyond lunar distances, and the Chinese and Indian space agencies have done lunar probes. But I haven't seen "spoof ET transmissions" on ESA's long-range plan, and they're very picky about only doing missions that have ben approved by the whole intergovernmental process. (I seem to recall one of the Pioneers being used as a test object for potential SETI systems - known location and Doppler drift, so if your system doesn't find it, you'd better fix something before joining the hunt. I do find links indicating that the SETI institute has used Pioneer 10 as a test object for several systems).

Yeah, of course, my bad.

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What brings us together is stronger than what pulls us apart

Weeding out signals of human origin will be pretty easy. I worked on the NASA SETI project some 20 years ago, before it was canceled (and made illegal). Earth orbiting satellites stand out like the proverbial "sore thumb"; they have a highly distinct variable Doppler shift as they pass overhead. That will be true, though perhaps less obvious, for any satellite in the solar system. Even most geosynchronous satellites are not fixed to one spot on the sky, if you look with enough precision. And if push comes to shove, as "they" say, it's a good bet that the DOD knows where everybody's geosynchronous satellites are.

The real question is what to do when you have a signal from a truly fixed target that you know is not one of "ours". One thing we expected was that natural processes would not emit that same kind of very narrow band radio signals that an artificial transmitter would, so just a narrow line would be enough to indicate something suspicious. But we discovered that is not necessarily the case. So to avoid all the hassle from Congress & the press, the Search for Extraterrestrial Intelligence (SETI) project became the High Resolution Microwave Survey (HRMS) project, with the added scientific benefit of a database of high spectral resolution data for interstellar chemistry & etc. Realizing that the chances of getting a real SETI hit were low, we thought the additional science goal would keep the project alive against a hostile Congress, but it was to no avail.

The factors likely to distinguish an artificial ("intelligent") signal from a natural signal are a combination of extremely narrow bandwidth (like 1 Hz or less) and modulation that looks non-natural, which is partly a subjective criterion. Remember, when the first pulsar was discovered, it was dubbed LGM-1, where LGM = Little Green Men, because the chirps were as precise as the precision clock in the observatory. But it did not take long to realize that nature could do that.

Even if we were to find a signal that looked "intelligent", we might actually never know for sure. Pulsars do almost everything an intelligent signal would do - they are fixed in one spot, they don't turn off, they are modulated with "technological" precision, and one could even interpret drifting sub-pulses as an "intelligent" signal. But we know they are not "intelligent". So even if we find candidates, they are likely I think to remain just that: Candidates. Unless somebody goes to great pains to make their signal obvious, we will simply never know if the signal is "artificial" or "natural". Even our own attempts to create such messages fell on our own deaf ears; signals intended to be deciphered by extraterrestrial intelligences could not be deciphered by our own scientists.

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The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell

Good point. That's why I focus on falsification. Its much easer to determine that a signal is NOT ET than to determine that it is.

The best I can do (or anyone else for that matter) is to collect the data, archive it for anyone to see, and hope for the best.

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