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LOFAR is the LOw Frequency ARray for radio astronomy. It is an ambitious project to build an interferometric array of radio telescopes distributed across the Netherlands and Northern Germany, with a total effective collecting area of up to 1 square kilometre. The processing of the data is done by a Supercomputer, situated at the University of Groningen. Interferometry is the applied science of combining two or more input points of a particular data type, such as optical measurements, to form a greater picture based on the combination of the two sources. ...
The 64 metre radio telescope at Parkes Observatory In contrast to an ordinary telescope, which produces visible light images, a radio telescope sees radio waves emitted by radio sources, typically by means of a large parabolic (dish) antenna, or arrays of them. ...
A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μÎÏ„Ïο (metro) = count/measure). ...
Front of the main building (Academiegebouw) of the University of Groningen The University of Groningen (Dutch: Rijksuniversiteit Groningen or RUG) is a university in Groningen, Netherlands. ...
LOFAR started as a new and innovative effort to force a breakthrough in sensitivity for astronomical observations at radio-frequencies below 250 MHz. Astronomical radio interferometers usually consist either of arrays of parabolic dishes (e.g. the One-Mile Telescope), arrays of one-dimensional antennas (e.g. the Molonglo Observatory Synthesis Telescope) or two-dimensional arrays of omni-directional dipoles (e.g. Tony Hewish's Pulsar Array). LOFAR combines aspects of many of these earlier telescopes -- in particular it uses the omni-directional dipole antennae as a phased array using the aperture synthesis technique developed in the 1950s. Like the earlier CLFST low-frequency radio telescope, the design of LOFAR has concentrated on the use of large numbers of relatively cheap antennas, with the mapping performed using aperture synthesis software. Image File history File links LOFAR,_ITS_Test_Station. ...
Image File history File links LOFAR,_ITS_Test_Station. ...
One antenna from the One-Mile Telescope The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO) was completed by the Radio Astronomy Group of Cambridge University in 1964. ...
Molonglo Observatory Synthesis Telescope The Molonglo Observatory Synthesis Telescope (MOST) is a radio telescope operating at 843 MHz. ...
Antony Hewish (born Fowey, Cornwall, May 11, 1924) is a British radio astronomer who won the Nobel Prize for Physics in 1974 (together with fellow radio-astronomer Martin Ryle) for his work on the development of radio aperture synthesis and its role in the discovery of pulsars. ...
The Interplanetary Scintillation Array (IPS Array or Pulsar Array) was built at the Mullard Radio Astronomy Observatory in 1967 and originally covered four acres (16,000 m²). It was extended in 1978 to nine, and re-furbished in 1989. ...
Aperture synthesis is a type of interferometry that mixes signals from a collection instruments to produce measurements having the same angular resolution as an instrument the size of the entire collection. ...
The Cambridge Low-Frequency Synthesis Telescope (CLFST) is an east-west aperture synthesis radio telescope currently operating at 151 MHz. ...
Aperture synthesis is a type of interferometry that mixes signals from a collection instruments to produce measurements having the same angular resolution as an instrument the size of the entire collection. ...
The electronic signals from the LOFAR antennas are digitised, transported to a central digital processor, and combined in software in order to map the sky. The cost is dominated by the cost of electronics and will follow Moore's law, becoming cheaper with time and allowing increasingly large telescopes to be built. So LOFAR is an IT-telescope. The antennas are simple enough but there are a lot of them - 25000 in the full LOFAR design. To make radio pictures of the sky with adequate sharpness, these antennas are to be arranged in clusters that are spread out over an area of ultimately 350 km in diameter. (In phase 1 that is currently funded 15000 antenna's and maximum baselines of 100 km will be built). Data transport requirements are in the range of many Tera-bits/sec and the processing power needed is tens of Tera-FLOPS.
The mission of LOFAR is to survey the universe at radio frequencies from ~10 – 240 MHz with greater resolution and greater sensitivity than previous surveys, such as the 7C and 8C surveys, and surveys by the Very Large Array (VLA) and Giant Meterwave Radio Telescope (GMRT). A megahertz (MHz) is one million (106) hertz, a measure of frequency. ...
Angular resolution describes the resolving power of a telescope. ...
The Seventh Cambridge Catalogue of Radio Sources (7C) See also Cambridge Radio Surveys: 1C - 2C - 3C - 4C - 5C - 6C - 7C - 8C - 9C 3CR Categories: | | | ...
The Eighth Cambridge Survey (8C) is an astronomical catalogue of celestial radio sources as measured at 38-MHz. ...
The Very Large Array (VLA) is a radio astronomy observatory located on the Plains of San Augustin, between the towns of Magdalena and Datil, some fifty miles (80 km) west of Socorro, New Mexico, USA. The VLA stands at , , at an altitude of 6970 ft (2124 m) above sea level. ...
Giant Metrewave Radio Telescope (GMRT), located near Pune in India, is the worlds largest radio telescope at metre wavelengths. ...
LOFAR will be the most sensitive radio observatory until the next generation of large array radio telescope, the Square Kilometre Array (SKA), comes online around 2020. Ska is a form of Jamaican music which began in the early 1960s. ...
2020 (MMXX) will be a leap year starting on Wednesday of the Gregorian calendar. ...
Science case The sensitivities and spatial resolutions attainable with LOFAR will make possible several fundamental new studies of the Universe as well as facilitating unique practical investigations of the environment of the earth. - In the very distant Universe (7 < z < 10), LOFAR can search for the signature produced by the reionization of neutral hydrogen. This crucial phase change is predicted to occur at the epoch the formation of the first stars and galaxies, marking the end of the so-called “dark ages”. The redshift at which reionization is believed to occur will shift the 1420 MHz line of neutral hydrogen into the LOFAR observing window.
- In the distant “formative” Universe (1.5 < z < 7), LOFAR will detect the most distant massive galaxies and will study the processes by which the earliest structures in the Universe (galaxies, clusters and active nuclei) form and probe the intergalactic gas.
- In the nearby Universe, LOFAR will map the 3-dimensional distribution of cosmic rays and global magnetic field in our own and nearby galaxies.
- The High Energy Universe, LOFAR will detect the ultra high energy cosmic rays as they pierce the Earth’s atmosphere. A dedicated test station for this purpose, LOPES, has been in operation since 2003.
- Within our own galaxy, LOFAR will detect flashes of low-frequency radiation from pulsars and short-lived transient events produced by stellar merging and interactions and will search for Jupiter-like extra-solar planets.
- Within our solar system, LOFAR will detect coronal mass ejections from the Sun and provide continuous large-scale maps of the solar wind. This crucial information about solar weather and its effect on the Earth will facilitate predictions of costly and damaging geomagnetic storms.
- Within the Earth’s immediate environment, LOFAR will map irregularities in the ionosphere continuously, detect the ionizing effects of distant gamma-ray bursts and the flashes predicted to arise from the highest energy cosmic rays, whose origin of is unclear.
- By exploring a new spectral window LOFAR is likely to make unexpected "serendipitous" discoveries. Detection of new classes of objects and/or new astrophysical phenomena have resulted from almost all previous facilities that open new regions of the spectrum, or pushed instrumental parameters, such as sensitivity by more than an order of magnitude
Much LOFAR science builds on fundamental areas of research that have been pursued intensively or pioneered within the Netherlands during the last half century. The LOPES project (LOFAR Prototype Station) is a cosmic ray detector array, located in Karlsruhe, Germany, and is operated in coincidence with an existing, well calibrated air shower experiment called KASCADE. There are different ways to observe cosmic rays, or, more accurately, the air showers that cosmic rays produce when...
Key projects
Timeline LOFAR was proposed to ASTRON in 1997. A feasibility study was carried out and international partners sought during 1999. In 2000 the Netherlands LOFAR Steering Committee was set up by the ASTRON Board with representatives from all interested Dutch university departments and ASTRON.
In November 2003 the Dutch Government allocated 52 Million Euro to fund the infrastructure of LOFAR under the Bsik programme. In accordance with Bsik guidelines, LOFAR was funded as a multidisciplinary sensor array that will facilitate research in geophysics, computer sciences and agriculture as well as astronomy.
In December 2003 LOFAR's Initial Test Station (ITS) became operational; this was an important milestone in the LOFAR development. The ITS system consists of 60 inverse V-shaped dipoles; each dipole is connected to a low noise amplifier (LNA), which provides enough amplification of the incoming signals to transport them over a 110 m long coaxial cable to the receiver unit (RCU).
On April 26, 2005, an IBM Blue Gene-L supercomputer was installed at the University of Groningen's math center, for LOFAR's data processing. This is now the 2nd most powerful supercomputer in Europe, after the MareNostrum in Barcelona[1]. April 26 is the 116th day of the year in the Gregorian Calendar (117th in leap years). ...
2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ...
For other uses, see IBM (disambiguation). ...
Blue Gene/L Blue Gene is a computer architecture project designed to produce several next-generation supercomputers, designed to reach operating speeds in the petaflops range, and currently reaching speeds over 280 teraflops (sustained). ...
A supercomputer is a computer that leads the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. ...
Front of the main building (Academiegebouw) of the University of Groningen The University of Groningen (Dutch: Rijksuniversiteit Groningen or RUG) is a university in Groningen, Netherlands. ...
Data processing is any computer process that converts data into information. ...
Europe is conventionally considered one of the seven continents of Earth which, in this case, is more a cultural and political distinction than a physiographic one, leading to various perspectives about Europes borders. ...
MareNostrum Supercomputer - CG rendered image. ...
Barcelona is the capital city of Catalonia, an autonomous community in Spain. ...
In July 2006 the first LOFAR station (Core Station 1, aka. CS1) will be put in the field using pre-production hardware. A total of 96 dual-dipole antennas (the equivalent of a full LOFAR station) will be grouped in 4 clusters, the central cluster with 48 dipoles and other three clusters with 16 dipoles each. The clusters will be distributed over an area of ~500m in diameter.
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