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Digital Puglia (SARA)

Digital Sky

InSAR
Interferometric
Synthetic Aperture
Radar

GIOD
Globally Interconnected Object Databases

LIGO
Laser Interferometer Gravitational-Wave Observatory)

XSIL
Extensible Scientific Interchange Language

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LIGO
(Laser Interferometer Gravitational-Wave Observatory)
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"The Laser Interferometer Gravitational-Wave Observatory (LIGO) will be a facility dedicated to the detection of cosmic gravitational waves and the harnessing of these waves for scientific research. It will consist of two widely separated installations within the United States, operated in unison as a single observatory. When it reaches maturity, this observatory will be open for use by the national community and will become part of a planned worldwide network of gravitational-wave observatories."
- from the LIGO Fact Sheet

LIGO may be able to detect some or all of these astrophysical sources of general-relativistic gravity waves:

Waves from the coalescence of massive objects such as neutron stars or black holes. The expected waveform may be represented in different ways, as a graph or as sounds.
Waves from rapidly-spinning compact objects that are asymmetric, perhaps a variety of neutron star.
Waves from supernovae.
Remnant gravitational radiation from the big bang.

Gravitational radiation has not been directly detected, although J. H. Taylor and R. A. Hulse were awarded the 1993 Nobel prize in physics for the indirect detection. Even with the powerful LIGO detector, any astrophysical signal will be so small that it will be buried in noise, and the only way to reliably extract the signal is through careful comparison and discrimination with many other possible sources. While the gravity-wave channel is a relatively low-bandwidth data source, the combination with hundreds of other channels provides roughly 18 MByte/sec, 24 hours a day, seven days a week.

CACR is collaborating with the LIGO Data Analysis System (LDAS) project, whose objective is to provide an "active digital library" to contain the archived data and processing facilities. We are currently engaged in the following activities.

Archiving the data from the interferometers using the HPSS system. We are providing not only data, but searching, filtering, and calibration services, and a variety of retrieval formats.
Metadata services that can find which data frames cover a certain time interval, history of the state of these complex intstruments, and low-resolution "thumbnail" images of the data frames.
Providing library services that allow a diverse group of investigators access to the archive, including libraries of possibly related events, such as gamma ray bursts and seismic events, fuindings of other investigators, and pointers to web pages and the scientific literature.
Providing computing services which are connected at high bandwidth to the data archive, so that a remote investigator need only download the relatively small result of the data-mining, rather than the enormous raw dataset.
Visualization software and services that allow investigators to see the signatures of canditate and simulated events, and their correlations with other data sources and computations. An example of such a system is the Gravitational Radiation Toolbox.
Porting the analysis algorithms to high-performance parallel machines.

Read the article written by Roy Williams for the CACR 1997 Annual Report (PDF Format).

Visit the LIGO web pages.