Searching for correlations in global environmental noise Karl Wette, Susan Scott and Antony Searle ACIGA Data Analysis Centre for Gravitational Physics The Australian National University

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 2 Outline Global correlations impact global networks Southern hemisphere monitoring station established Data acquisition from LIGO, Virgo Software to handle datasets approaching Tb

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 3 Global gravitational astronomy Multiple observatories required to triangulate source and veto false alarms Southern hemisphere detector could complete a global network Confidence in results requires knowledge of correlated disturbances to detectors

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 4 Local environmental monitoring In The ANU Gravitational Wave Research Facility  Optical cleanroom on damped slab (VRM, HPTF etc.)  Not at Gingin, but still far from existing observatories Three seismometers (XYZ)  Supplied by Dept. Earth Sciences, from the field  One down for repairs Tri-axial magnetometer (XYZ)  Off-the-shelf instrument Electrical supply voltage monitor  Locally built  Australia has 60 Hz power grid

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 5 Local data acquisition Outside clean-room Power supplies  Several supply different components, minimising cross-talk Anti-aliasing filters GPS receiver  1 PPS signal Signal generator  2048 Hz locked to GPS NI ADC card  Sampling triggered by generator

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 6 Local data management NI LabView software extended to write acquired channels directly to standard Frame files Script uploads completed frames to ANUSF multi-terabyte Mass Data Storage System (MDSS)

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 7 Global data acquisition Basic environmental channels are large  1 Gb, per day, per site Important to download only needed channels, not files  Use LIGOtools (getFrames) + LDAS to produce and download an environmental monitoring RDS LIGO does not archive these channels outside science runs, so this must be done in near real time  Use Benoit’s goodwill Data grid technologies  Local work on extensions to permit distribution at channel, not file level  Future feasibility will depend on relative costs of internet and physical (couriered tape or disk) transfer  Part of major Australian data grid effort, with astronomers and particle physicists

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 8 ACIGA Data Analysis Cluster 16 P4 processors 1 Tb RAID1 storage 14 Gb ECC RAM LDAS Data grid Environmental data analysis

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 9 Pipeline Accesses all data Highly parallel Runs on ACIGA Data Analysis Cluster Produce spectrograms Automated detection of unusual features  Ensemble of statistical tests

K Wette, S Scott, A Searle Searching for correlations in global environmental noise ACIGA Data Analysis 10 Future Upgrade  AU$10k this year for better acquisition system  Postdoc includes this project Analysis  Long timescale coherences  Coherence bursts in spectrograms  Impact on global astronomy  Veto recommendations