
:''For other uses of the acronym "VLA" see VLA (disambiguation)'' The Very Large Array (VLA) is a radio astronomy observatory located on the Plains of San Agustin, between the towns of Magdalena, New Mexico and Datil, New Mexico, some fifty miles (80 km) west of Socorro, New Mexico, New Mexico, United States. The VLA stands at , at an altitude of 6970 ft (2124 m) above sea level. It is a component part of the National Radio Astronomy Observatory (NRAO). ==Characteristics== The observatory consists of 27 independent radio antennae, each of which has a dish diameter of 25 meters and weighs 230 tons. The antennae are arrayed along the three arms of a Y-shape (each of which measures 21 km). Using the railroad tracks that follow each of these arms – and that, at one point, intersect with U.S. Highway 60 at a level crossing – and a specially designed lifting locomotive, the antennae can be physically relocated to a number of prepared positions, allowing aperture synthesis interferometry with a maximum baseline of 36 km: essentially, the array acts like a single antenna with that diameter. The highest angular resolution that can be reached is about 0.05 arcseconds. There are four commonly used configurations, designated A (the largest) through D (the tightest, when all the dishes are within 600 m of the center point). The observatory normally cycles through all the various possible configurations (including several hybrids) every 16 months: in other words, once the massive efforts needed to move two dozen 230-ton highly sensitive scientific instruments have been made, the antennae are not moved again for a period of three to four months. The VLA site also currently serves as the control center for the Very Long Baseline Array (VLBA), a Very Long Baseline Interferometry array of ten 25-meter dishes located from Hawaii in the west to the U.S. Virgin Islands in the east that constitutes the world's largest dedicated, full-time astronomical instrument. ==Past and future== United States Congress approval for the VLA project was given in August 1972, and construction began some six months later. The first antenna was put into place in September 1975 and the complex was formally inaugurated in 1980, after a total investment of United States dollar $78.5 million. With a view to upgrading the venerable 1970s technology with which the VLA was built, a proposal has been floated for the conversion of the VLA into the Expanded Very Large Array ("EVLA"). The upgrade would enhance the instrument's sensitivity, frequency range, and resolution, and would entail installing new hardware at the San Agustin site and the construction and installation of up to eight additional dishes in other parts of the state of New Mexico, up to 300 km away, connected to the hub via fiber-optic links. ==Popular culture== The VLA observatory featured prominently in Carl Sagan's 1985 novel ''Contact (novel)'', albeit much expanded (131 dishes!) and renamed the "Argus Array". When the time came for Hollywood to make the motion picture version of the story (''Contact (movie)'', 1997), much outdoor footage was shot at the VLA site. The number of dishes visible on screen was artificially increased by means of Computer-generated imagery, however, and the canyon depicted as being in the vicinity of the VLA is actually Chelly Canyon in neighboring Arizona. ==Visiting== The VLA site is open to visitors year round during daylight hours. A visitor center houses a museum and a gift shop, and a self-guided walking tour is available. ==Related topics== * Very Long Baseline Interferometry * List of radio telescopes == External link == * [http://www.vla.nrao.edu NRAO VLA] – official site. Radio telescopes Interferometers
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Words begining with Very_Large_Array:
Very_Large_Array
Very_Large_Array.jpg
Very_Large_Array_dish_detail.jpg
Very Large Array
:''For other uses of the acronym "VLA" see VLA (disambiguation)'' The Very Large Array (VLA) is a radio astronomy observatory located on the Plains of San Agustin, between the towns of Magdalena, New Mexico and Datil, New Mexico, some fifty miles (80 km) west of Socorro, New Mexico, New Mexico, United States. The VLA stands at , at an altitude of 6970 ft (2124 m) above sea level. It is a component part of the National Radio Astronomy Observatory (NRAO). ==Characteristics== The observatory consists of 27 independent radio antennae, each of which has a dish diameter of 25 meters and weighs 230 tons. The antennae are arrayed along the three arms of a Y-shape (each of which measures 21 km). Using the railroad tracks that follow each of these arms – and that, at one point, intersect with U.S. Highway 60 at a level crossing – and a specially designed lifting locomotive, the antennae can be physically relocated to a number of prepared positions, allowing aperture synthesis interferometry with a maximum baseline of 36 km: essentially, the array acts like a single antenna with that diameter. The highest angular resolution that can be reached is about 0.05 arcseconds. There are four commonly used configurations, designated A (the largest) through D (the tightest, when all the dishes are within 600 m of the center point). The observatory normally cycles through all the various possible configurations (including several hybrids) every 16 months: in other words, once the massive efforts needed to move two dozen 230-ton highly sensitive scientific instruments have been made, the antennae are not moved again for a period of three to four months. The VLA site also currently serves as the control center for the Very Long Baseline Array (VLBA), a Very Long Baseline Interferometry array of ten 25-meter dishes located from Hawaii in the west to the U.S. Virgin Islands in the east that constitutes the world's largest dedicated, full-time astronomical instrument. ==Past and future== United States Congress approval for the VLA project was given in August 1972, and construction began some six months later. The first antenna was put into place in September 1975 and the complex was formally inaugurated in 1980, after a total investment of United States dollar $78.5 million. With a view to upgrading the venerable 1970s technology with which the VLA was built, a proposal has been floated for the conversion of the VLA into the Expanded Very Large Array ("EVLA"). The upgrade would enhance the instrument's sensitivity, frequency range, and resolution, and would entail installing new hardware at the San Agustin site and the construction and installation of up to eight additional dishes in other parts of the state of New Mexico, up to 300 km away, connected to the hub via fiber-optic links. ==Popular culture== The VLA observatory featured prominently in Carl Sagan's 1985 novel ''Contact (novel)'', albeit much expanded (131 dishes!) and renamed the "Argus Array". When the time came for Hollywood to make the motion picture version of the story (''Contact (movie)'', 1997), much outdoor footage was shot at the VLA site. The number of dishes visible on screen was artificially increased by means of Computer-generated imagery, however, and the canyon depicted as being in the vicinity of the VLA is actually Chelly Canyon in neighboring Arizona. ==Visiting== The VLA site is open to visitors year round during daylight hours. A visitor center houses a museum and a gift shop, and a self-guided walking tour is available. ==Related topics== * Very Long Baseline Interferometry * List of radio telescopes == External link == * [http://www.vla.nrao.edu NRAO VLA] – official site. Radio telescopes Interferometers
See other meanings of words starting from letter:
V
Words begining with Very_Large_Array:
Very_Large_Array
Very_Large_Array.jpg
Very_Large_Array_dish_detail.jpg
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