a short summary of the
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DESCRIPTIONA short Summary of the. Data Analysis Meeting, January 2001 Golm including a list of decisions and action items Copies of electronic presentations available on DC home page & GEO documentation server. Benno: Detector Status. - PowerPoint PPT Presentation
A shortSummaryof theData Analysis Meeting, January 2001Golmincluding a list of decisions and action items
Copies of electronic presentations available on DC home page & GEO documentation server
MCs and 1200m cavity operative. 1st monolithic suspension about to be installed.Full detector to be installed in 2001.See Bennos presentationProgramming to be done:Minute maker debuggingFrame viewerLabview- DAQS connection (how to display 800 channelsof data)data transfer Hannover Golm/K.Zusereduced data set + compression
Data taking periods:2 weeksJuly 2001no SR1 week October 2001with SRinf.>December 2001
Benno: Detector Status
Problems:# of channels limited reflective memory (Ian:takes too long to adapt to GEO)exchange processor (Pentium or faster BAJA-compatible )use more than one processor card solve problem before beginning of April when DC startsGPS time stampsReliable generation of framesNo frame viewerData storage limited to a few hoursToo much workload on Ian Taylor
Martin Hewitson, Karsten Ktter: DAQS
Goals:develop detector noise modelKnow detector resonancesDetector commissioning and subsystem understandingstability of calibrationstudy of correlation of disturbancesTriggers, vetoesDetector characterisation &data preparation pipeline
Analysis of engineering dataImplementation of TRIANA toolsDevelop sophisticated tools (trend estimation tools)Design of DC pipelineSoftware librarianDC documentation
?where does data preparation take place? Vetoes, line removal, calibration etc.
Alicia Sintes: DC + data conditioning
Benno Willke: data taking plans
There are already data availableDC people, please come to the site to learn about the detector!
Data taking plan:DAQS will run all time once it is set up and detector is operativeLast 4 days always available on RAID systemAccess policy will depend on demandStatus documented in html databaseInput from DC group needed to develop a final list of stored channelsList of detector channels (storage depth TBD) and environmental channels
Action Items:extraction of Labview channels out of frame filessetup data chain to access datalearn how to deal with Gbytes of dataattend DC workshop 26. Feb. 2. Mar. in Ruthe
Uta Weiland: Detector Resonances
Catalogue (available @ GEO documentation server) of resonances gives information on Component or signal causing or showing oscillation Frequency Quality factorInclude information about magnitude and stability of resonance frequency.
Karsten Ktter: data baseDatabase keeps track of DAQS status (which signals, resolution, sampling rate, gain, comments)Detector statusInformation is stored in frame filesChoosing frame file can be done via database
Input into database:detector status input by experimentalist via web interfaceDAQS status automatically maintained by configman. Updated when changes take place
Output of database: Web interface for looking up data
Simple and robust tools needed:Trend estimationVisual observation of large transientsDiagnostics: PSDLine discriminatorTransients not obvious to the eye: Spectrogram (S(f),t)Density estimation: Histograms, Kernel est., Hypothesis testing (chi^2)Channel correlation: Cross correlation, CoherenceData in a single band: Bandpass filter, heterodyning
Line removal tools: Coherent line removal (Matlab & C, offline), kalman filter (Matlab), adaptive line enhancement (Matlab,LAL), cross channel regression [frequency or time domain](C, Matlab), median based line tracker(Matlab, offline), multi taper (GRASP), resampling based harmonic removal (C++).Soma Mukherjee: Overview of tools for noise characterization I
Time Series AnalysisOutput will be non-stationary over long periods of time.Need to achieve better resolution in est. of power spectral density
-> AutoRegressive Moving Average (ARMA) modelsNo limits on frequency resolutionCan be made adaptiveStudy evolution of ARMA coeff. as indicator for non-stationarity
Discussion on why lines should be removed? Lines of detectors within the same mains system could cause correlations between detectors. Database (cross linked to Utas data base) of removed lines and affected frequencies and trends in the lines removed.Test data analysis to see whether line removal is necessary and does not harm the data.
R. Balasubramanian: Overview of Tools for noise Characterization II
Time-Frequency methodsSignal track search (Detector for quasiperiodic bursts) (LAL code) limited to a few sec by computational needs N^2 log(N)Power monitoring Inter channel correlations Wavelet transforms
Soumya Mohanty: DC pipelineNeed automated tools pointing out interesting segments (i.e. changes in PSD, Transients) to handle large amounts of data. Not for commissioning stage.2 types: DC pipelinedata preparation/conditioning pipelinePipeline design has to investigate cross coupling effects between pipeline subsystemsDesign status: tools identified, computational costs and statistical characterisation can be studied.Pipeline design will affect planning of other data analysis components Concrete design exists: Lined out candidate pipeline (available on web page)Several candidates have to be comparedRequirements:Fast enough to work onlineLanguage: C++(LDAS, DMT, VEGA), Java (TRIANA)Database: depends on data mining tasks requirementsClose co-operation with experimentalists requiredAlmost all available in matlab (TBC)Use sequential files instead of relational databaseTo test implement as a large matlab program then transfer to C++ or TRIANADevelop metrics of performanceTest against sim. and real dataRequires additional manpower to get ready in time (i.e. for the data taking test runs in Ruthe)
Discussion: AliciaGoals of session: Define and assign tasks, deadlines, telecon dates&groups, FAQS , expectations from theorists and experimentalistsTasks:DAQS workshop Feb.26th -March 2nd: define specific goalsNeed coordinator who sets specific tasks and monitors progress?Harry: visualization of data very important, e.g. comparison of historical to current data. Bernard: most basic tools are available in TRIANA or can easily be built from existing blocks. (but exp. have to learn how to put them together)Sathya: Experimentalists should prepare wishlist in this workshopprepare beforehand: minute reader, TRIANA GEO(raw+frame)-readerAnalysis of GEO data: analysis of different sets of data for specific noise sources, correlations or misbehaviour. Detector debugging and commissioning toolsImplementation of tools needed into TRIANADevelopment of sophisticated tools for data based diagnosticsPipeline designSoftware librarianMaintain DC documents: put onto GEO documentation serverCatalogue of expected detector signaturesSignatures found in the data of terrestrial or instrumental originCompendium of problems and solutionsSoftware docMilestones: Pipeline ready for July data taking (in Matlab)
Coherent search : Efficient code existing that can cover about day for about 10^5 points over the sky. Highly parallel as frequ. Segments are distributed to diff. Processors,i.e. designed to work on clusters of PCs.Alicia: Hough transform (incoherent) first code running in individual pieces. Still too slow. Designed other more promising algorithm. Code in C not LAL. Hough transform produces candidates over long periods of time. Use coherent search for good candidates. Best use two different non-optimal incoherent algorithms and only use common candidates for coherent search. On the whole: programs well on the way. Important to keep # of gaps in data stream low. Need more info on the influence of gaps onto data quality. Periodic failures are worst.Alberto is building up catalogue of all possible sources.Bernard Schutz: CW search summary
B.S. Sathyaprakash: Status of binary inspiral and merger search softwareMerger phase only important for BH binaries
Prospect of detecting Binary BHs:S/N about 5 @ optimum masses (~70 M) of BHs15 M ,15 M @ 100Mpc detectable with S/N~3
Post Newtonian approximation does not converge well enough. Go to P-approximants. P5 (P-approximant to 2.5 PN order) will be used for the filters.
Including merger phase does significantly (factor order 1.5-2) increase S/N in upper mass range > 20 M Inclusion of quasi-normal ringing after merging does not help much. Requires accurate knowledge of merger phase waveforms.# of wave templates to be used decreases with mass as merger frequency goes down.-> BH bins may be observable (1-2/y) by initial network
Codes in LAL format, which is 4 times slower than C-codeT- and P- approximants ready for point-mass circular orbits Eccentric orbits & BD waveforms= almost readySpinning binaries need more research. No software yet
Soumya Mohanty: Issues in GW bursts detectionTransient testsSeveral tests availableThorough comparison requiredCriteria for comparisonReceiver operating characteristics Robustness against noise modelRobustness against signal modelComputational requirementsEstablishing confidence in detectionWhat level of confidence required? What false alarm rate?False alarms: terrestrial burst, non stationary noiseImproving confidence:Coincidence with other detectorsCoincidence with astronomical events (time delay not known a priori) use dedicated robotic wide-field telescopes to try to verify signalAnti-coincidence with auxiliary channelsFalse alarm rate for aux. Chans could be highUpper limitsRate at a certain S/NMax S/N in certain class of burstsCombining upper limits with coincidence analysisImportant to characterize background noiseDetector CharacterizationInstantaneous detector status requiredCharacterization of rate and amplitude distribution of terrestrial bursts required for up