Rob Dekker wrote:
[...]

Yes, I assume there are signals out there. If they have been observed already,
they the will have been discarded by current analysis (scoring) methods.

Good optimism! (:-))


[...]

All right...
I still dont know the real problems with signal analysis, but I assume it's RFI.

First of all, I think we should forget about finding beacon signals (narrowband, deliberately
aimed signals with a message for us) . 1240 Mhz is way to low a frequency for interstellar beacons
(too expensive to operate for ET).

Mmmm... That cuts out the most /easily/ detectable stuff for what detection capability we have available at present.

I believe that it is much more likely that ET signals out there detectable with Arecibo - seti@home,
will be CW radar signals (semi-long (10-100sec), narrowband radar pulses), and these
will be the first ones we will pick up.

Whether the Arecibo + s@h (classic) system could detect a seti-equivalent our own radars is a good question... and how far out?

(Wooley estimations please? (:-))

Unless the source solar system is doing a LOT of radar, I suspect we're sunk without trace at source (:-((


[...]

Here are some suggestions :

(1) To rule out RFI you need to recognize it : To automate recognition, you need to
have a database of know RFI signals or some pattern analysis.

[...]

Yep, and there's various ways of doing this. One question is whether to have a central database, or to have a distributed database with some form of peer-to-peer between contributors. Also, how do you handle the 90% of users that try for a few hours and then get bored never to be seen again? Worse, what of those users that appear 'reliable' and then just vanish without trace? Data loss??

(2) Set up a 'top-1000' list of promising signals, make them down-loadable (with their
same-sky point counterparts). Us SETI enthausists to sift through them and correlate

[...]

Does this assume independent data acquisition? Or other dedicated targeted searches?

Most of what we have at present is the data surreptitiously acquired from hanging off the back end of whatever else is happening at Arecibo.

Perhaps look at whatever else is being done by The Planetary Society, Seti League and Argos and any others?

(3) Repetition analysis :

[...]

The correlation analysis done for the 200 interesting signals was +-75Hz or so.
With a large computer farm, a much more thorough correlation can be done
on all same-sky-different-time work units.

A big problem there is practical access to all the WU results. The database is likely too large (and controversial) for a raw download for multiple public users.

If you have a _serious_ proposal backed up by well argued and well researched methods, then you could try offering you proposal for consideration...

Need I continue ?

Many things are possible!

Meanwhile, there is still the danger of an overenthusiastic ignorant
media shouting wolf a few too many times and then discrediting all the
seti projects.

As long as we keep the top-1000 list open and steady at 1000, there will
not be any media attention.. Just more seti enthausiasts sifting through prospect signals.

It's when we say that one particular signal is 'promising' is when media are interested.

The lack of a steady stream of signals claims/disclaims is partly what has the media so desperate for /any/ claim. If there are no claims, then the media people are very happy to make up their own hyped claims as has recently been seen!

Perhaps we should have a monthly 'best hits' web page, similar to the 'Near Earth Objects' and other astro-search bulletin type pages. The problem there is for someone at Berkeley to have the time and interest to program an automated web page...



Something that would be good would be to Boinc up some signal analysis that takes advantage of the Gflops of nVidia GPUs!

eg:
http://www.bionicfx.com/media/BIONICFX_09012004.pdf
ftp://download.nvidia.com/developer/presentations/2004/SIGGRAPH/ImageProcessing.pdf
http://developer.nvidia.com/object/fast_math_routines.html
http://developer.nvidia.com/docs/IO/8229/Cg-Paper-Slides.pdf
(FFTs:)
http://developer.nvidia.com/docs/io/4106/Technology_Directions.pdf
http://developer.nvidia.com/object/sdk_samples.html

(Get hacking (:-))


Keep searchin',
Martin