very brief update on the geo mystery noise investigations
DESCRIPTION
Very brief update on the GEO mystery noise investigations. Stefan Hild for the GEO600 team 15th ILIAS WG1 meeting, March 2008, Cascina. Photographs by A. Freise. Introduction. Just a quick update: following up the mystery noise session + brainstorming at last ILIAS meeting. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/1.jpg)
Stefan Hild for the GEO600 team
15th ILIAS WG1 meeting, March 2008, Cascina
Very brief update on the GEO mystery noise investigations
![Page 2: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/2.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 2
IntroductionJust a quick update: following up the mystery noise session + brainstorming at last ILIAS meeting.See: http://www.ego-gw.it/ILIAS-GW/WP1docs/hild_231007.ppt for further detail…
Pho
tog
raph
s by
A.
Fre
ise
![Page 3: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/3.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 3
How to tackle the mystery noise ?
Mystery noise
![Page 4: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/4.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 4
How to tackle the mystery noise ?
Mystery noise
Characteristics ofthe mystery noise
Displacement noiseYes / No ?
Any clues from the observation? Displacement-like or not? Stationary? Related to glitches? ....
![Page 5: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/5.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 5
How to tackle the mystery noise ?
Mystery noise
Fundamentalnoises
Projectednoises
Characteristics ofthe mystery noise
Displacement noiseYes / No ?
Is the gap real? All projections correct? Are all noises projected? Calculations of fundamental noises correct?
![Page 6: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/6.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 6
How to tackle the mystery noise ?
Mystery noise
Fundamentalnoises
Projectednoises
UpconversionScattered light
Characteristics ofthe mystery noise
Exotic noises
Displacement noiseYes / No ?
Can we rule out the usual candidates: non-linearly coupling noises? How about exotic noises ? ....
![Page 7: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/7.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 7
![Page 8: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/8.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 8
Low vs high power
The gap looks smaller at low power, but …
Nominal power low power
![Page 9: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/9.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 9
Low vs high power
… but the mystery stays roughly the same
![Page 10: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/10.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 10
![Page 11: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/11.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 11
![Page 12: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/12.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 12
Frequency noise projection: A smoking gun ?
The change of the mystery noise from 550Hz to 1kHz tuning looks suspiciously similar to the change of the frequency noise transfer function.
Slide from October presentation
Is there any correlation at SR-tuning of 350 Hz ???
![Page 13: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/13.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 13
Mystery noise vs frequency-noise-TF
550 Hz and 1kHz fit pretty well, but 350 Hz does not.
Could indicate that part of the noise is caused by frequency noise
![Page 14: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/14.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 14
Frequency noise
Part of the mystery noise was caused by frequency noise.
See Hartmut’s talk
![Page 15: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/15.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 15
Projections to uncalibrated errorpoints
In order to rule out any strange effects from calibration process we wanted to do noise projections to the uncalibrated errorpoints.
The gap turns to be of same size as for h(t) projections.
![Page 16: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/16.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 16
Time domain noise projections
Wanted to perform noise projections in time domain => taking phase correlations into account.
Frequency domain and time domain projections agree pretty well.
For more details, see Jerome‘s talk
![Page 17: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/17.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 17
New Projection: Beam jitter on main PD
![Page 18: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/18.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 18
![Page 19: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/19.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 19
Holographic noise
http://arxiv.org/abs/0709.0611http://arxiv.org/abs/0706.1999http://arxiv.org/abs/astro-ph/0703775
Needs more attention and investigations ….
![Page 20: Very brief update on the GEO mystery noise investigations](https://reader036.vdocuments.us/reader036/viewer/2022062410/56815546550346895dc31758/html5/thumbnails/20.jpg)
Stefan Hild ILIAS WG1, March 2008 Slide 20