New Instrumentation and Gravitational Radiation.

[beecee]

I just cam across this interesting article.......

https://phys.org/news/2017-07-tetrahedron.html

extracts:

"Thanks to an innovative ring laser design, geophysicists at LMU can now measure and monitor Earth's rotation with unprecedented accuracy. The new instrument in Fürstenfeldbruck will be formally inaugurated this week.

Moreover, quantifying the minimal variations in the many different components of the Earth's motions is not solely a matter of academic interest. For example, all GPS-based navigational systems must be periodically recalibrated in order to take account of these variations, which would otherwise give rise to significant errors in determining one's position on the globe".

Read more at: https://phys.org/news/2017-07-tetrahedron.html#jCp

 

The article also further links to the following......

https://phys.org/news/2017-03-deep-earth-rotational-effects.html

extract:

"A group from the Italian National Institute for Nuclear Physics' (INFN) Laboratori Nazionali del Gran Sasso (LNGS) are working with a research program aimed at measuring the gyroscopic precession Earth undergoes due to a relativistic effect called the Lense-Thirring effect. This program, called Gyroscopes in General Relativity (GINGER), would eventually use an array of such highly sensitive RLGS. For now, they have successfully demonstrated its prototype, GINGERino, and acquired a host of additional seismic measurements necessary in their efforts".

Read more at: https://phys.org/news/2017-03-deep-earth-rotational-effects.html#jCp

 

The second article is detailed in a paper at.....

http://aip.scitation.org/doi/10.1063/1.4977051

 

Abstract:

GINGERino is a large frame laser gyroscope investigating the ground motion in the most inner part of the underground international laboratory of the Gran Sasso, in central Italy. It consists of a square ring laser with a 3.6 m side. Several days of continuous measurements have been collected, with the apparatus running unattended. The power spectral density in the seismic bandwidth is at the level of 10−10 (rad/s)/Hz⎯⎯⎯⎯⎯√10−10 (rad/s)/Hz. A maximum resolution of 30 prad/s30 prad/s is obtained with an integration time of few hundred seconds. The ring laser routinely detects seismic rotations induced by both regional earthquakes and teleseisms. A broadband seismic station is installed on the same structure of the gyroscope.First analysis of the correlation between the rotational and the translational signal is presented.

 

OK, My question is rather simple...Could either of these highly precised instruments be able to be calibrated to observe or indicate gravitational waves?

For that matter, could the GP-B have done or indicated the same thing?

[Mordred]

Not as far as I know. The length on each axis of LIGO is what determines the detection frequency range on GW waves.

 

A circular design would not have the required lengths to pick up a 90 degree phase shift. Which in antenna basics is a quarter wavelength. This is the primary reason each leg is 4 km long at LIGO.

 

However just to be sure I will look closer at the specifications on the above detectors. If I determine its possible I will post a correction.

Edited July 17, 2017 by Mordred

[beecee]

Not as far as I know. The length on each axis of LIGO is what determines the detection frequency range on GW waves.

 

A circular design would not have the required lengths to pick up a 90 degree phase shift. Which in antenna basics is a quarter wavelength. This is the primary reason each leg is 4 km long at LIGO.

 

However just to be sure I will look closer at the specifications on the above detectors. If I determine its possible I will post a correction.

Vinaka! [Thank you in Fijian ]

[swansont]

Earth orientation measurements are a lot less precise than LIGO. 30 prad is what they get after a few hundred seconds of integration. If that's averaging out white noise, it means the precision gets better as the square root of the time. So the precision at 0.1 sec is around 50x smaller, and the ringdown needs measurements at this or shorter times.

 

And that's not even close to what would be needed (by 15 orders of magnitude, I think)

 

So even if this could do it in principle, even if it detected the kind of motion, which it doesn't

[beecee]

Thanks fellas, just a thought that popped into my head when I read the articles.....

[beecee]

Save starting a new thread...some more welcome news on gravitational wave detectors.....

http://www.virgo-gw.eu/docs/AdV_joins_O2_en.pdf

VIRGO joins LIGO for the “Observation Run 2” (O2) data-taking period Today,

"Tuesday August 1st 2017, the VIRGO detector based in Europe has officially joined “Observation Run 2” (O2) and is now taking data alongside the American-based twin LIGO detectors. This major step forward for the VIRGO Collaboration is the outcome of a multi-year upgrade program, whose primary goal was to significantly improve the detector performance in terms of sensitivity. “The last months have been spent on commissioning VIRGO, and this went very well. We are eager to start our first science run, joining LIGO at this exciting time for our field” says Jo van den Brand of Nikhef and VU University Amsterdam, the spokesperson of the VIRGO collaboration.

Although the VIRGO sensitivity is, for the time being, at a lower level of those of the LIGO interferometers, it is adequate for confirming a potential detection with LIGO and would allow locating sources of gravitational waves in the sky with greater accuracy. The current VIRGO sensitivity significantly exceeds the previous VIRGO record sensitivity, achieved in 2011 before dismantling the detector to start its upgrade. VIRGO is now a brand new instrument comprising several new components, which have been made work together in less than one year, during the so-called commissioning phase. “It took many years of intense and innovative work to realize the ambitious objectives of the VIRGO upgrade. I wish to recognize the dedication of the members of the VIRGO Collaboration, of the EGO staff and of the participating labs” says Federico Ferrini, the director of the European Gravitational Observatory (EGO).

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

 

and here......

https://www.ligo.caltech.edu/WA/news/ligo20170801

Edited August 11, 2017 by beecee

[Mordred]

Thanks for bringing the above to our attention. I know I will study the above lol as RL allows.