1. LIGO-G9900XX-00-M LIGO and GriPhyN Carl Kesselman Ewa Deelman Sachin Chouksey Roy Williams Peter Shawhan Albert Lazzarini Kent Blackburn CaltechUSC/ISI

2. LIGO-G9900XX-00-M LIGO Scientific Collaboration 2 LIGO Virtual Data Grid Caltech MIT LIGO Livingston LIGO Hanford

3. LIGO-G9900XX-00-M LIGO Scientific Collaboration 3 Pictures

4. LIGO-G9900XX-00-M LIGO Scientific Collaboration 4 LIGO Overview l To detect gravitational waves predicted by Einstein’s theory of relativity. l Waves created from »Rapidly spinning asymmetric compact objects eg. pulsars »Mergers of black holes, neutron stars -- gamma bursts? »Supernova collapse (and post-collapse R-modes) »Starquakes in neutron stars »Primæval GW from early universe l Installation in Louisiana and Washington State »Other projects: Virgo (Italy), GEO (Germany), Tama (Japan)

5. LIGO-G9900XX-00-M LIGO Scientific Collaboration 5 Physics and Virtual Data frequency Supernova Primeval GW Background Mergers BH/NS CW (eg pulsar) Merger Ringdowns time Each source type has different freq/time charactaristics  different virtual data requirements

6. LIGO-G9900XX-00-M LIGO Scientific Collaboration 6 LIGO Data Time series, 16 kHz down to 1 Hz ~1000 channels : »Gravity wave »seismic, magnetometer, microphone, engineering, … Power spectra, cross spectra, sonogram, … Events »Each has time and SNR (signal to noise ratio) »Candidate inspiral events from matched filter »Other pattern matching »“Examine the big ones, histogram the small ones”

7. LIGO-G9900XX-00-M LIGO Scientific Collaboration 7 Processing Network »NVO is federation, LIGO is coincidence »In both cases registration is important LIGO vs NVO vs HEP detectorevents pattern matching filter reduce HEP objects detector datacube events pattern matching filter reduce LIGO, NVO RDBMS 1D,2D

8. LIGO-G9900XX-00-M LIGO Scientific Collaboration 8 Data Access LDAS (Ligo Data Analysis System) »Script (Tcl) based »Primarily for onsite analysis and archiving »Talks to local files, Hanford/Livingston »Has a filtering language –stack-based, like Matlab –functions eg power spectrum, fft, resample LARS »Can talk to local, HPSS files »Can do subsetting »Simple program, simple protocol

9. LIGO-G9900XX-00-M LIGO Scientific Collaboration 9 Activities 1. Virtual Data »A: Language & Architecture –Naming is Time/Channel/Transformation –Smart subsetting »B: LigoVista web display –Archive at-a-glance + drill-down 2. Replication »A: Realtime mirror –Hanford/Livingston/Virgo nternational coincidence study »B: Fault-tolerant mirror –from Caltech to UW/Milwaukee 3. Pulsar search »backfill on Condor farms

10. LIGO-G9900XX-00-M LIGO Scientific Collaboration 10 1A: Virtual Data: Language Virtual Data: »Times + Channels, –eg 668371475-668372499 (GPS time, seconds since 1981) –L0: PEM-LVEA_SEIS*, L1:LSC-AS_Q »Transformations to Virtual Channels –eg. L0:PEM-EX-SEISX- L0:PEM-LVEA-SEISX / resample(L1:LSC-AS_Q, 1, 64) Use LARS and Globus Replica Catalog l For each requested data value, need to »Determine if it is instantiated; if so, where; if not, how to compute it »Plan data movements and computations required to obtain all results »Execute this plan

11. LIGO-G9900XX-00-M LIGO Scientific Collaboration 11 1A: Virtual Data: Architecture existing in development planned Connectivity Request Manager “local” storage HPSS at Caltech Other Remote Storage Replica Catalog Replica Management Replica Selection LDAPFTPGridFTP Derived Data Catalog Transfor- mation Catalog LARS Prot. LIGO Application Channel, start time, stop time Virtual Data URL Power spectrum of seismic channels P. Charlton

12. LIGO-G9900XX-00-M LIGO Scientific Collaboration 12 1B: Virtual Data: LigoVista Overview of archive in a web browser »Time based –month, week, day, hour,.... »Machine state –lock status, science run, event density,.... »Drill down to raw data –Transformed data »Uses Virtual Data framework –compute on the fly and cache

13. LIGO-G9900XX-00-M LIGO Scientific Collaboration 13 2A: Replication:Realtime Look for coincidence in Ligo-Virgo data LIGO Virgo Interferometer, seismic. etc Interferometer, seismic. etc LDAS analysis event stream streaming bidirectional transatlantic replication

14. LIGO-G9900XX-00-M LIGO Scientific Collaboration 14 2A: Whistlers from Lightning?

15. LIGO-G9900XX-00-M LIGO Scientific Collaboration 15 2B: Replication: Fault-tolerance HPSS@CaltechBeowulf@UWiscMilwaukee Replica Catalog Replication API Penn State UT Brownsville GridFTP Master archive replicated at LSC sites Fault tolerant

16. LIGO-G9900XX-00-M LIGO Scientific Collaboration 16 3. Pulsar Search Infinite computation on finite data! »Tiny, precise signals in deep noise »Search on 4D space: sky position, pulsar frequency, spindown, 6 months data Time (months) Frequency (Hz) Frequency modulation by Earth movement UT Brownsville UW Milwaukee Caltech CACR UW Madison Condor farms 0.5 TByte “image” frequency bins frequency time frequency

17. LIGO-G9900XX-00-M LIGO Scientific Collaboration 17 frequency time frequency