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Plateau De Bure Interferometer
The Plateau de Bure Interferometer (PdBI) was a six-antenna interferometer on the Pic de Bure (2550 m) in the French Alps, operated by the Institut de radioastronomie millimétrique. In 2014, it has been replaced by the Northern Extended Millimeter Array. It was specifically designed for millimetre-wave observations and specialises in studies of line emission from molecular gas and radio continuum of cold dust. The interferometer consisted of six antennas with a diameter of 15 m each. These antennas could be placed in a T-shaped pattern, with north–south track of 368 m and an east–west track of 768 m. There were 32 stations along these tracks where the antennas can be positioned. Observing bands are at 3, 2, 1.8 and 0.8 mm. At an observing wavelength of 3 mm (100 GHz frequency) each of these telescopes could resolve two objects 45 arcseconds apart from each other on the sky. In an interferometer, these 45″ are actually the size of the field of view. So a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometer
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, remote sensing, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pic De Bure
Pic de Bure is a prominent mountain of the Dauphiné Alps in France, culminating at a height of , the third highest peak of the Dévoluy Mountains The Devoluy Mountains is a limestone massif located in Hautes-Alpes, France. It is part of the Dauphiné Prealps and is bordered by the Drac River to the north and the Buëch River to the south and west and is a popular destination for hiking, m .... The Plateau de Bure Interferometer is located on its slopes. Notes {{DEFAULTSORT:Bure Mountains of the Alps Mountains of Hautes-Alpes Dauphiné Prealps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Alps
The French Alps are the portions of the Alps mountain range that stand within France, located in the Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur regions. While some of the ranges of the French Alps are entirely in France, others, such as the Mont Blanc massif, are shared with Switzerland and Italy. At , Mont Blanc (Italian: ''Monte Bianco''), on the France–Italy border, is the highest mountain in the Alps, and the highest Western European mountain. Notable towns in the French Alps include Grenoble, Chamonix, Annecy, Chambéry, Évian-les-Bains and Albertville. Ranges and summits Ski areas The largest connected ski areas are: # Les Trois Vallées (Courchevel, Méribel, La Tania, Brides-les-Bains, Saint-Martin-de-Belleville, Les Menuires, Val Thorens and Orelle): 338 slopes, 600 km of pistes. # Portes du Soleil ( Avoriaz, Châtel, Morzine, Les Gets, Saint-Jean d'Aulps, La Chapelle d'Abondance, Abondance, Montriond, Swiss resorts): 288 slopes, 650&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institut De Radioastronomie Millimétrique
Institut de Radioastronomie Millimetrique (IRAM) is an international research institute and Europe's leading center for radio astronomy at millimeter wavelengths. Its mission is to explore the universe, study its origins and its evolution with two of the most advanced radio facilities in the world: * The NOEMA observatory (NOrthern Extended Millimeter Array), an array of currently eleven 15-meter antennas located in the French Alps on the Plateau de Bure at more than 2550 meters above sea level. NOEMA is the most powerful millimeter observatory of the Northern Hemisphere. * The IRAM 30-meter telescope, located at 2850 meters altitude on Pico Veleta in the Spanish Sierra Nevada (Andalucia, Spain). The telescope is the world's premier single-dish facility for astronomical research in the millimeter wavelength range. Both sites are at high altitude to reduce the absorption by water vapour in Earth's atmosphere. The telescopes are supported by the IRAM offices and laboratories in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Extended Millimeter Array
The Northern Extended Millimeter Array (NOEMA) is one of the largest astronomical facilities on European ground and the most powerful radio telescope in the Northern Hemisphere operating at millimeter wavelengths. It consists of a large array of twelve 15-meter antennas that can spread over distances of up to 1.7 kilometers, working together as a single telescope. NOEMA is the successor of the Plateau de Bure Interferometer and is run by the international research institute IRAM (Institut de radioastronomie millimétrique). The observatory operates at over 2500 meters above sea level on one of the most extended European high altitude sites, the Plateau de Bure in the French Alps. Together with IRAM's second observatory, the IRAM 30-meter telescope, it is part of the global Event Horizon Telescope array. Operation Instead of operating one giant telescope, NOEMA relies on several smaller and easily movable antennas placed on tracks. Together, the NOEMA antennas have the resol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcsecond
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in astron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Tramway
An aerial tramway, sky tram, cable car, ropeway, aerial tram, telepherique, or seilbahn is a type of aerial lift which uses one or two stationary ropes for support while a third moving rope provides propulsion. With this form of lift, the grip of an aerial tramway cabin is fixed onto the propulsion rope and cannot be decoupled from it during operations. In comparison to gondola lifts, aerial tramways generally provide lower line capacities and higher wait times. Terminology Because of the proliferation of such systems in the Alpine regions of Europe, the French and German names, ''téléphérique'' and ''Seilbahn'', respectively, are often also used in an English language context. ''Cable car'' is the usual term in British English, as in British English the word ''tramway'' generally refers to a railed street tramway while in American English, ''cable car'' may additionally refer to a cable-pulled street tramway with detachable vehicles; e.g., San Francisco's cable cars. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Independent
''The Independent'' is a British online newspaper. It was established in 1986 as a national morning printed paper. Nicknamed the ''Indy'', it began as a broadsheet and changed to tabloid format in 2003. The last printed edition was published on Saturday 26 March 2016, leaving only the online edition. The newspaper was controlled by Tony O'Reilly's Irish Independent News & Media from 1997 until it was sold to the Russian oligarch and former KGB Officer Alexander Lebedev in 2010. In 2017, Sultan Muhammad Abuljadayel bought a 30% stake in it. The daily edition was named National Newspaper of the Year at the 2004 British Press Awards. The website and mobile app had a combined monthly reach of 19,826,000 in 2021. History 1986 to 1990 Launched in 1986, the first issue of ''The Independent'' was published on 7 October in broadsheet format.Dennis Griffiths (ed.) ''The Encyclopedia of the British Press, 1422–1992'', London & Basingstoke: Macmillan, 1992, p. 330 It was produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Radio Telescopes
This is a list of radio telescopes – over one hundred – that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list is sorted by region, then by name; unnamed telescopes are in reverse size order at the end of the list. The first radio telescope was invented in 1932, when Karl Jansky at Bell Telephone Laboratories observed radiation coming from the Milky Way. Africa Antarctica Asia Australia Europe North America South America Arctic Ocean Atlantic Ocean Indian Ocean Pacific Ocean Space-based Under construction or planned construction Proposed telescopes Gallery of big dishes File:FastTelescope*8sep2015.jpg, alt=Five hundred meter Aperture Spherical Telescope under construction, The 500 meter Five hundred meter Aperture Spherical Telescope (FAST), under construction, China (2016) File:GBT.png, alt=Green Bank Telescope, The 100 meter Green Bank Telescope, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Astronomical Observatories
This is a list of astronomical observatories ordered by name, along with initial dates of operation (where an accurate date is available) and location. The list also includes a final year of operation for many observatories that are no longer in operation. While other sciences, such as volcanology and meteorology, also use facilities called observatories for research and observations, this list is limited to observatories that are used to observe celestial objects. Astronomical observatories are mainly divided into four categories: space-based, airborne, ground-based, and underground-based. Many modern telescopes and observatories are located in space to observe astronomical objects in wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere (such as ultraviolet radiation, X-rays, and gamma rays) and are thus impossible to observe using ground-based telescopes. Being above the atmosphere, these space observatories can also avoid the effects of atmo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combined Array For Research In Millimeter-wave Astronomy
The Combined Array for Research in Millimeter-wave Astronomy (CARMA) was an astronomical instrument comprising 23 radio telescopes, dedicated in 2006. These telescopes formed an astronomical interferometer where all the signals are combined in a purpose-built computer (a correlator) to produce high-resolution astronomical images. The telescopes ceased operation in April 2015 and were relocated to the Owens Valley Radio Observatory for storage. The Atacama Large Millimeter Array in Chile has succeeded CARMA as the most powerful millimeter wave interferometer in the world. Location According to the CARMA observatory catalog, the median height of all telescope pads was at an elevation of . The observatory was located in the Inyo Mountains to the east of the Owens Valley Radio Observatory, at a site called Cedar Flat (after relocating thCedar Flat Group Campsto the west of Hwy-168), accessed through Westgard Pass. The high elevation site was chosen to minimize millimeter wave abso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Large Millimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The array has been constructed on the elevation Chajnantor plateau - near the Llano de Chajnantor Observatory and the Atacama Pathfinder Experiment. This location was chosen for its high elevation and low humidity, factors which are crucial to reduce noise and decrease signal attenuation due to Earth's atmosphere. ALMA provides insight on star birth during the early Stelliferous era and detailed imaging of local star and planet formation. ALMA is an international partnership amongst Europe, the United States, Canada, Japan, South Korea, Taiwan, and Chile. Costing about US$1.4 billion, it is the most expensive ground-based telescope in operation. ALMA began scientific observations in the second half of 2011 and the first images were relea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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