instrumental and environmental noise in geo600
DESCRIPTION
Instrumental and environmental noise in GEO600. Picture of GEO in stormy weather?? Or pics of tractors with trees?. Joshua Smith for the GEO 600 team. North building. Overview. A selection of recent detector characterization work. Environmental: Seismic Dust Magnetic fields / Mains. - PowerPoint PPT PresentationTRANSCRIPT
Joshua Smith, Elba, Italy 31.05.06
Elba, Italy 31.05.06
Joshua Smith for the GEO 600 team
Picture of GEO in stormy weather??
Or pics of tractors with trees?
Instrumental and Instrumental and environmental noise in GEO600environmental noise in GEO600
North building
Joshua Smith, Elba, Italy 31.05.06
OverviewOverview
Environmental:o Seismico Dusto Magnetic fields / Mains
Instrumental:o Noise Projectionso Tracking couplingso Noise subtractiono Noise vetoes
A selection of recent detector characterization work
Joshua Smith, Elba, Italy 31.05.06
Seismic / up-conversionSeismic / up-conversion
H @ 240Hz
H @ 290Hz
H @ 340Hz
Seis @ 49Hz
0 Time [h] 3.5
Am
plit
ude
(max
)
Joshua Smith, Elba, Italy 31.05.06
DustDust
Joshua Smith, Elba, Italy 31.05.06
Power glitchesPower glitches
Detector output
Input port power
Joshua Smith, Elba, Italy 31.05.06
Back-coupling?Back-coupling?
Strain coupling to DC power
Dark port DC Power
Strain back-coupling doesn’t explain instrumental channel coincidence
Joshua Smith, Elba, Italy 31.05.06
Power glitches vs. dustPower glitches vs. dust
Dark port DC power glitch count
Dark port DC power glitch count
Particle count
Dark port DC power glitch count
Input port DC power glitch count
0 Time [m] 180
Joshua Smith, Elba, Italy 31.05.06
Particle waves filteredParticle waves filtered14020
455
30.2
(Par
ticl
es/c
u.ft
)/10
00
A
a
Joshua Smith, Elba, Italy 31.05.06
Dust made loudest glitchesDust made loudest glitches
Before filter After filter
Time [h] Time [h]Det. output BLRMS @~ 170Hz
Joshua Smith, Elba, Italy 31.05.06
Magnetic fields / MainsMagnetic fields / Mains
Joshua Smith, Elba, Italy 31.05.06
Magnetic field glitchesMagnetic field glitches
B glitches H glitches
Linear coupling, coherence
Joshua Smith, Elba, Italy 31.05.06
Magnetic field “projection”Magnetic field “projection” B-field nearly limiting noise around 100Hz?
o Coupling not yet understood o Checks: magnetometer measures B-field, IFO back-coupling ruled out
Joshua Smith, Elba, Italy 31.05.06
Hourly mains glitchesHourly mains glitches
Hourly series start:o 24 secs after GPS houro 10 secs after UTC hour
24s
Joshua Smith, Elba, Italy 31.05.06
Mag./mains coinc. with HMag./mains coinc. with H
Fr e
quen
c y [
Hz]
Magnetometer central building ~ 50coinc./8hrs
Time-freq glitch maps
Time-shifted coincidence
Mains monitor central building ~ 30coinc./8hrs
Time [h] Time [h]0 08 8
50
0
50
0
Time shift [s] Time shift [s]1 1-1 -1
Fre
quen
c y [
Hz]
Joshua Smith, Elba, Italy 31.05.06
Noise ProjectionsNoise Projections
Joshua Smith, Elba, Italy 31.05.06
Noise BudgetNoise Budget
Alignment actuation
Scattering, up-conversion, ? Shot, dark, osc. phase
Joshua Smith, Elba, Italy 31.05.06
Tracking noise transfer func’sTracking noise transfer func’s
Tracked:
Signal Recycl. FB
Osc. Phase
Laser intensity
Frequency
Amp ratio ~ 1
phase diff ~ 0
Joshua Smith, Elba, Italy 31.05.06
Transfer func’s: long-term (10d)Transfer func’s: long-term (10d)
10 days, most projections:
+/- 10% mag
+/- 10 degs phase
So, long-term stable
Ratio/Diffs drifts
Histogram of drifts
Joshua Smith, Elba, Italy 31.05.06
Noise transfer func’s: short-termNoise transfer func’s: short-term
+/- 20% mag. variations on second timescales!
Joshua Smith, Elba, Italy 31.05.06
Noise SubtractionNoise Subtraction
Joshua Smith, Elba, Italy 31.05.06
Detector output and noiseDetector output and noise
Detector output
Noise chans.
Record subset
Noise projection
Noise budget
Improved H
Joshua Smith, Elba, Italy 31.05.06
Noise subtraction requirementsNoise subtraction requirements
Subtraction factor depends on amplitude ratio and phase difference of filter used and real transfer function response.
Joshua Smith, Elba, Italy 31.05.06
Noise subtraction resultsNoise subtraction results
Time domain subtraction, simple IIR filters fit to measured TF response.
Ratio H/(H-Projs)
But, no reduction of up-conversion
Joshua Smith, Elba, Italy 31.05.06
Technical noise vetoTechnical noise veto
Joshua Smith, Elba, Italy 31.05.06
Noise veto: eg. injectionNoise veto: eg. injection
H
Michelson oscillator phase noise
Joshua Smith, Elba, Italy 31.05.06
Noise veto performanceNoise veto performance
“Robust vetoes for gravitational-wave burst triggers using known instrumental couplings”
P. Ajith, M. Hewitson, J. R. Smith, K. A. Strain, submitted to CQG, http://arxiv.org/abs/gr-qc/0605079
Estimated veto efficiency vs. rejection probability
for the chosen thresholds.
Joshua Smith, Elba, Italy 31.05.06
The endThe end
'falco tinnunculus',
better know as 'Turmfalke'
Joshua Smith, Elba, Italy 31.05.06
Noise subtraction IINoise subtraction II
Used simple IIR filters
- good match to simple transfer function
Joshua Smith, Elba, Italy 31.05.06
Statistical dust veto?Statistical dust veto?
MID VIS veto TF map and timeshifted results