What is the Difference Between the S5R3 and S5R4 Data Analyses?
6 Aug 2008 20:47:36 UTC
Topic 193824
(moderation:
There has been speculation that the new S5R4 is different than the S5R3 run because "the stretch of observation time (a segment of the S5 LIGO science run) that is covered in S5R4 is longer than in S5R3, and basically every work unit looks at the complete stretch of time, but only for a small frequency window." [Thanks to Bikeman for the quote! ;)
What exactly are the differences between the old and new runs in terms of how they are being analyzed, and if they encompass the same or different data collection runs?
And what is hoped to be achieved with the new run versus what was achieved with the S5R3 run?
Thanks!
What is the Difference Between the S5R3 and S5R4 Data Analyses?
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I too am curious about this very subject, but I figured that the project gurus wouldn't have time to address this until the project itself was working smoothly again.
Once things calm down, I'd love some insight into the very same questions that Bob has asked about! :)
RE: There has been
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I can't improve on the Bikeman there.
I think it safe to say it's the same general aim - find GW signals, or upper bounds thereof, on continuous wave sources ( basically those with a persistent enough regularity in their emission to be detectable as such ). My guess is also generally furthering the whole proof-of-concept of the enterprise, that is finding what works!
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
RE: ...I think it safe to
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Thanks! I guess a question would be is this new analysis considered more sensitive in digging the signals out of the data, or perhaps it is just another way of approaching the problem, or perhaps it is analyzing data that has not been analyzed previously?
RE: RE: ...I think it
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The latter. The S5 LSC Science run lasted about two and a half years, when we started S5R2/3 only the data of the first year was available. S5R4 is looking at the rest of the data from S5, where the sensitivity of the detectors was higher than in the first year. Also we got more usable data out of the second year, which improves the sensitivity of the analysis. That, however, also means that for the workunits the data volume has increased and the amount of computational work necessary to process them, too.
BM
BM
RE: The latter. The S5 LSC
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Thank you Bernd! :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Aye, thanks for the
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Aye, thanks for the information Bernd... makes perfect sense to explain the longer tasks, etc. I'm glad to know we're digging into new, virgin data as well! :)
After Mike's initial reply, I was tempted to give him a virtual smack in the forehead and say, "Oh really Captain Obvious? You think we're still looking for gravity waves?", but I'd never say something like that in type because it would be rude.
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Oh... Ahh, erm... Ooops. ;)
/me ducks. :-D
RE: Aye, thanks for the
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blush - well yes, I agree, call me 'Captain O' :-)
'Please Your Honor, it's been a long week' :-)
I been in 'auto answer mode' alas :-)
[ actually I don't know how a virtual forehead smack feels, hmmmm .... lets not go there ]
Even with all the distress on the WU/credit thing, I'm quite excited that the R4 analysis is pushing the boundaries yet some more. My new reading ( see adjacent sociology thread ) has a great emphasis on two things -> sufficient sensitivity to detect the very, very, very small disturbances that GW's represent AND the hope that when that day arrives we'll know it's not something else. This is the penalty of venturing into an area where the signal is dramatically smaller than the noise. Hence a deeper dig into better data is cool .... :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Hi! The new WUs will also
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Hi!
The new WUs will also use a feature of the apps that was there for some time but is now actually used: weights for the Hough pattern matching analysis. IIRC, basically it's taking into account that not all data is equally significant, because of noise level in the input data and directional variations in the sensitivity of the IFOs. This should increase the accuracy of the search as well.
CU
Bikeman
RE: ...That, however, also
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Thank you, that is very exciting to hear!
And having to do additional computational work is very worthwhile when it increases the chance for success! This is a very exciting processing run! :)
RE: blush - well yes, I
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Let me guess.... If I came to you in your chosen profession and said, "It hurts when I do this!", would you mime your best Groucho Marx cigar and say, "Well... don't DO that!" ;)