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| [[File:VLBA St Croix-04.jpg|thumb|250px|right|The eastern terminus of the VLBA, on [[Saint Croix, U.S. Virgin Islands]]]]
| | Eusebio Stanfill is what's indicated on my birth certificate although it is not the name on particular birth certificate. Idaho is our birth city. I work as an arrangement clerk. As a man what While i really like is coming off as but I'm thinking with regards to starting something new. You can also find my website here: http://circuspartypanama.com<br><br>Here is my blog - [http://circuspartypanama.com hack clash of clans Jailbreak] |
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| The '''Very Long Baseline Array''' ('''VLBA''') is a system of ten [[radio telescope]]s which are operated remotely from their [[Array Operations Center]] located in [[Socorro, New Mexico]], as a part of the [[National Radio Astronomy Observatory]] (NRAO). These ten [[radio antenna]]s work together as an array that forms the longest system in the world that uses [[very long baseline interferometry]]. The longest baseline available in this [[interferometer]] is about {{convert|8611|km|0}}.<ref name=saha2010/>
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| The construction of the VLBA began in February 1986 and it was completed in May 1993. The first [[radio astronomy|astronometrical]] observation using all ten antennas was carried out on May 29, 1993. The total cost of building the VLBA was about 85 million dollars.
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| Each receiver in the VLBA consists of a [[dish antenna|parabolic dish antenna]] 25 [[meter]]s (82 feet) in diameter, along with its adjacent control building. This contains the supporting [[electronics]] and machinery for the receiver, including low-noise electronics, [[digital computer]]s, data storage units, and the antenna-pointing machinery. Each of the antennas is about as tall as a ten-story building when the antenna is pointed straight up, and each antenna weighs about 218 [[metric ton]]s (240 [[short ton]]s).
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| The signals from each antenna are recorded on a bank of approximately one-[[terabyte]] hard disc drives, and the information is time-stamped using [[atomic clock]]s. Once the disc drives are loaded with information, they are carried to the Pete V. Domenici Science Operations Center at the NRAO in Socorro. There the information undergoes [[signal processing]] in a powerful set of digital computers that carry out the interferometry. These computers also make corrections for the rotation of the Earth, the slight shifts in the [[crust (geology)|crust of the Earth]] over time, and other small [[measurement error]]s
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| == Observations by the VLBA ==
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| The Very Long Baseline Array usually makes radio [[observation]]s at [[wavelength]]s from three [[millimeter]]s to 28 [[centimeter]]s, or in other words, at [[frequencies]] from 0.3 [[gigahertz]] to 96 gigahertz. Within this frequency range, the VLBA observes in eight different [[frequency band]]s that are useful for radio astronomy. The VLBA also makes observations in two narrow radio bands below one gigahertz that include spectral lines produced by bright maser emissions.
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| The VLBA radio telescopes are located at:
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| {{Location map+ | USA
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| | width = 400
| |
| | caption = VLBA locations (red) and HSA locations (blue) in the [[contiguous United States]]
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| | places =
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| {{Location map~ | USA
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| | label = Hancock
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| | position =
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| | mark = Locator_Dot.png
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| | lat_deg = 42.93362
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| | lon_deg = -71.98681
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| }}
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| {{Location map~ | USA
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| | label = North Liberty
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| | position =
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| | mark = Locator_Dot.png
| |
| | lat_deg = 41.77165
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| | lon_deg = -91.574133
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| }}
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| {{Location map~ | USA
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| | label = Fort Davis
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| | position =
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| | mark = Locator_Dot.png
| |
| | lat_deg = 30.635214
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| | lon_deg = -103.944826
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| }}
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| {{Location map~ | USA
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| | label = Los Alamos
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| | position =
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| | mark = Locator_Dot.png
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| | lat_deg = 35.78233
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| | lon_deg = -106.25568
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| }}
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| {{Location map~ | USA
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| | label = Pie Town
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| | position = left
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| | mark = Locator_Dot.png
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| | lat_deg = 34.30107
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| | lon_deg = -108.11912
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| }}
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| {{Location map~ | USA
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| | label = Kitt Peak
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| | position =left
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| | mark = Locator_Dot.png
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| | lat_deg = 31.956253
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| | lon_deg = -111.612361
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| }}
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| {{Location map~ | USA
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| | label = Owens Valley
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| | position =
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| | mark = Locator_Dot.png
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| | lat_deg = 37.23176
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| | lon_deg = -118.27714
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| }}
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| {{Location map~ | USA
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| | label = Brewster
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| | position =bottom
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| | mark = Locator_Dot.png
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| | lat_deg = 48.13117
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| | lon_deg = -119.68325
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| }}
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| {{Location map~ | USA
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| | label = Green Bank
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| | position =right
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| | mark = Location dot blue.svg
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| | lat_deg = 38.255924
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| | lon_deg = -79.502341
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| }}
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| {{Location map~ | USA
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| | label = VLA
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| | position = bottom
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| | mark = Location dot blue.svg
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| | lat_deg = 34.079643
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| | lon_deg = -107.370591
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| }}
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| }}
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| {| class="wikitable"
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| ! [[Toponymy]]
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| ! [[U.S. state]]
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| ! [[Geographic coordinate system]]
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| |
| |
| |-----
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| | [[St. Croix, Virgin Islands|St. Croix]]
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| | [[U.S. Virgin Islands]]
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| | {{coord|17.75652 |-64.58376}}
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| | SC
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| |-----
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| | [[Hancock, New Hampshire|Hancock]]
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| | [[New Hampshire]]
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| | {{coord|42.93362|-71.98681}}
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| | HN
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| |-----
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| | [[North Liberty, Iowa|North Liberty]]
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| | [[Iowa]]
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| | {{coord|41.77165|-91.574133}}
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| | NL
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| |-----
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| | [[Fort Davis, Texas|Fort Davis]]
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| | [[Texas]]
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| | {{coord|30.635214|-103.944826}}
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| | FD
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| |-----
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| | [[Los Alamos, New Mexico|Los Alamos]]
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| | [[New Mexico]]
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| | {{coord|35.78233|-106.25568}}
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| | LA
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| |-----
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| | [[Pie Town, New Mexico|Pie Town]]
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| | [[New Mexico]]
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| | {{coord|34.30107|-108.11912}}
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| | PT
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| |-----
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| | [[Kitt Peak]]
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| | [[Arizona]]
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| | {{coord| 31.956253|-111.612361}}
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| | KP
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| |-----
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| | [[Owens Valley, California|Owens Valley]]
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| | [[California]]
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| | {{coord|37.23176|-118.27714}}
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| | OV
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| |-----
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| | [[Brewster, Washington|Brewster]]
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| | [[Washington (State)|Washington]]
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| | {{coord|48.13117|-119.68325}}
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| | BR
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| |-----
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| | [[Mauna Kea]]
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| | [[Hawaii]]
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| | {{coord|19.80159|-155.45581}}
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| | MK
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| |}
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| The use of the VLBA can be scheduled dynamically, and its sensitivity can be improved by a factor of five by including other radio telescopes such as the [[Very Large Array]] (VLA) in New Mexico and the [[Green Bank Telescope]] in [[West Virginia]] with the VLBA. Four other sites are brought online for as much as 100 hours per four-month trimester. In this configuration, the entire array is known as the '''High-Sensitivity Array''' ('''HSA''').<ref>{{cite web|url=http://www.vlba.nrao.edu/astro/obstatus/current/node5.html|title=NRAO Antenna Sites}}</ref> These sites, with coordinates, are as follows:
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| {{Location map+ | World
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| | width = 400
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| | caption = VLBA locations (red) and HSA locations (blue) around the world
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| | places =
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| {{Location map~ | World
| |
| | label = St. Croix
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| | position =
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| | mark = Locator_Dot.png
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| | lat_deg = 17.75652
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| | lon_deg = -64.58376
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| }}
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| {{Location map~ | World
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| | label = Mauna Kea
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| | position =
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| | mark = Locator_Dot.png
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| | lat_deg = 19.80159
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| | lon_deg = -155.45581
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| }}
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| {{Location map~ | World
| |
| | label = Arecibo
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| | position = bottom
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| | mark = Location dot blue.svg
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| | lat_deg = 18.203660
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| | lon_deg = -66.451110
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| }}
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| {{Location map~ | World
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| | label = Effelsberg
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| | position =
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| | mark = Location dot blue.svg
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| | lat_deg = 50.3130
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| | lon_deg = 6.53003
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| }}
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| }}
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| {| class="wikitable"
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| ! [[Toponymy]]
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| ! [[US state|State]]
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| ! [[Geographic coordinate system]]
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| !
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| |-----
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| | [[Arecibo]]
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| | [[Puerto Rico]]
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| | {{coord|18|20|36.60|N|66|45|11.10|W}}
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| | AR
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| |-----
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| | [[Green Bank, West Virginia|Green Bank]]
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| | [[West Virginia]]
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| | {{coord|38|25|59.24|N|79|50|23.41|W}}
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| | GB
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| |-----
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| | [[Very Large Array]]
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| | [[New Mexico]]
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| | {{coord|34|04|43.75|N|107|37|05.91|W}}
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| | Y27
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| |-----
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| | [[Effelsberg]]
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| | [[Germany]]
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| | {{coord|50|31|30|N|6|53|00.3|E}}
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| | EB
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| |}
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| ==Baseline distance and angular resolution==
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| Distance between each VLBA baseline (km):<ref>{{cite web|url=http://www.vlba.nrao.edu/astro/obstatus/current/node30.html|title=NRAO Website}}</ref> The longest baseline in the array is {{convert|8611|km|0}}.<ref name=saha2010/>
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| | |
| {| class="wikitable" border="1"
| |
| |-
| |
| !
| |
| !SC
| |
| !HN
| |
| !NL
| |
| !FD
| |
| !LA
| |
| !PT
| |
| !KP
| |
| !OV
| |
| !BR
| |
| !MK
| |
| !EB
| |
| !AR
| |
| !GB
| |
| !Y27
| |
| |-
| |
| |SC
| |
| |...
| |
| |2853
| |
| |3645
| |
| |4143
| |
| |4458
| |
| |4579
| |
| |4839
| |
| |5460
| |
| |5767
| |
| |8611
| |
| |6822
| |
| |238
| |
| |2708
| |
| |4532
| |
| |-
| |
| |HN
| |
| |2853
| |
| |...
| |
| |1611
| |
| |3105
| |
| |3006
| |
| |3226
| |
| |3623
| |
| |3885
| |
| |3657
| |
| |7502
| |
| |5602
| |
| |2748
| |
| |829
| |
| |3198
| |
| |-
| |
| |NL
| |
| |3645
| |
| |1611
| |
| |...
| |
| |1654
| |
| |1432
| |
| |1663
| |
| |2075
| |
| |2328
| |
| |2300
| |
| |6156
| |
| |6734
| |
| |3461
| |
| |1064
| |
| |1640
| |
| |-
| |
| |FD
| |
| |4143
| |
| |3105
| |
| |1654
| |
| |...
| |
| |608
| |
| |564
| |
| |744
| |
| |1508
| |
| |2345
| |
| |5134
| |
| |8084
| |
| |3922
| |
| |2354
| |
| |515
| |
| |-
| |
| |LA
| |
| |4458
| |
| |3006
| |
| |1432
| |
| |608
| |
| |...
| |
| |236
| |
| |652
| |
| |1088
| |
| |1757
| |
| |4970
| |
| |7831
| |
| |4246
| |
| |2344
| |
| |226
| |
| |-
| |
| |PT
| |
| |4579
| |
| |3226
| |
| |1663
| |
| |564
| |
| |236
| |
| |...
| |
| |417
| |
| |973
| |
| |1806
| |
| |4795
| |
| |8014
| |
| |4365
| |
| |2551
| |
| |52
| |
| |-
| |
| |KP
| |
| |4839
| |
| |3623
| |
| |2075
| |
| |744
| |
| |652
| |
| |417
| |
| |...
| |
| |845
| |
| |1913
| |
| |4466
| |
| |8321
| |
| |4623
| |
| |2939
| |
| |441
| |
| |-
| |
| |OV
| |
| |5460
| |
| |3885
| |
| |2328
| |
| |1508
| |
| |1088
| |
| |973
| |
| |845
| |
| |...
| |
| |1214
| |
| |4015
| |
| |8203
| |
| |5255
| |
| |3323
| |
| |1025
| |
| |-
| |
| |BR
| |
| |5767
| |
| |3657
| |
| |2300
| |
| |2345
| |
| |1757
| |
| |1806
| |
| |1913
| |
| |1214
| |
| |...
| |
| |4398
| |
| |7441
| |
| |5585
| |
| |3326
| |
| |1849
| |
| |-
| |
| |MK
| |
| |8611
| |
| |7502
| |
| |6156
| |
| |5134
| |
| |4970
| |
| |4795
| |
| |4466
| |
| |4015
| |
| |4398
| |
| |...
| |
| |10328
| |
| |8434
| |
| |7028
| |
| |4835
| |
| |-
| |
| |EB
| |
| |6822
| |
| |5602
| |
| |6734
| |
| |8084
| |
| |7831
| |
| |8014
| |
| |8321
| |
| |8203
| |
| |7441
| |
| |10328
| |
| |...
| |
| |6911
| |
| |6335
| |
| |8008
| |
| |-
| |
| |AR
| |
| |238
| |
| |2748
| |
| |3461
| |
| |3922
| |
| |4246
| |
| |4365
| |
| |4623
| |
| |5255
| |
| |5585
| |
| |8434
| |
| |6911
| |
| |...
| |
| |2545
| |
| |4317
| |
| |-
| |
| |GB
| |
| |2708
| |
| |829
| |
| |1064
| |
| |2354
| |
| |2344
| |
| |2551
| |
| |2939
| |
| |3323
| |
| |3326
| |
| |7028
| |
| |6335
| |
| |2545
| |
| |...
| |
| |2516
| |
| |-
| |
| |Y27
| |
| |4532
| |
| |3198
| |
| |1640
| |
| |515
| |
| |226
| |
| |52
| |
| |441
| |
| |1025
| |
| |1849
| |
| |4835
| |
| |8008
| |
| |4317
| |
| |2516
| |
| |...
| |
| |}
| |
| | |
| Minimum angular resolution:
| |
| | |
| {| class="wikitable" border="1"
| |
| |-
| |
| ! Wavelength (cm)
| |
| !90
| |
| !50
| |
| !21
| |
| !18
| |
| !13
| |
| !6
| |
| !4
| |
| !2
| |
| !1
| |
| !0.7
| |
| |-
| |
| |<math>\theta_{HPBW}</math> (milliarcseconds)
| |
| |22
| |
| |12
| |
| |5.0
| |
| |4.3
| |
| |3.2
| |
| |1.4
| |
| |0.85
| |
| |0.47
| |
| |0.32
| |
| |0.17
| |
| |}
| |
| | |
| ==See also==
| |
| * [[List of radio telescopes]]
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| | |
| ==References==
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| {{Reflist|refs=
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| | |
| <ref name=saha2010>{{citation | first1=Swapan Kumar | last1=Saha | title=Aperture Synthesis: Methods and Applications to Optical Astronomy | series=Astronomy and Astrophysics Library | publisher=Springer | year=2010 | isbn=1-4419-5709-X | page=81 | url=http://books.google.com/books?id=BIHe2Mmv08cC&pg=PA81 }}</ref>
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| <!-- <ref name=obsap2012>{{citation | display-authors=1 | first1=Pierre | last1=Lèna | first2=Daniel | last2=Rouan | first3=François | last3=Lebrun | first4=François | last4=Mignard | first5=Didier | last5=Pelat | title=Observational Astrophysics | series=Astronomy and Astrophysics Library | translator=Stephen Lyle | edition=3rd | publisher=Springer | year=2012 | isbn=3-642-21814-8 | page=282–284 | url=http://books.google.com/books?id=jvrnX7iZ5mEC&pg=PA282 }}</ref> -->
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| | |
| }}
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| | |
| ==External links==
| |
| * [http://www.nrao.edu/index.php/about/facilities/vlba Official site]
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| | |
| {{Radio-astronomy}}
| |
| | |
| [[Category:Radio telescopes]]
| |
| [[Category:Interferometric telescopes]]
| |
Eusebio Stanfill is what's indicated on my birth certificate although it is not the name on particular birth certificate. Idaho is our birth city. I work as an arrangement clerk. As a man what While i really like is coming off as but I'm thinking with regards to starting something new. You can also find my website here: http://circuspartypanama.com
Here is my blog - hack clash of clans Jailbreak