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Ukrainian T-shaped Radio Telescope, Second Modification
The Ukrainian T-shaped Radio telescope, second modification (official abbreviation UTR-2) is the world's largest low-frequency radio telescope at decametre wavelengths. It was completed in 1972 near the village of Hrakovo (), 15 km west-south-west from Shevchenkove, Ukraine. The telescope is operated by the Institute of Radio Astronomy of the Ukrainian Academy of Sciences. The UTR-2 consists of an array of 2040 dipole elements in two arms each containing 6 rows of elements, oriented in a T shape: a north–south arm consisting of 1440 elements covering an area of 1800×60 meters, and an east–west arm consisting of 600 elements covering an area of 900×60 meters. The basic element is a broadband cage dipole 1.8 m in diameter and 8 m long made of galvanized steel wire, mounted 3.5 m above the ground, with a balun to connect it to the transmission line. The dipoles are all oriented along the east–west axis, with the spacing between rows of 7. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Telescope
A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night. Since astronomical radio sources such as planets, stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in trackin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decametre
A decametre ( International spelling as used by the International Bureau of Weights and Measures and by most English speaking countries, United States spelling dekameter or decameter,), symbol dam ("da" for the SI prefix deca-, "m" for the SI unit metre), is a unit of length in the International System of Units (SI) equal to ten metres. While any combination of SI prefix and unit can be used, many are rarely used in practice; the decametre is used less frequently than other units of length. One practical use is for altitude of geopotential heights in meteorology. The volumetric form ''cubic decametre'' is convenient for describing large volumes of water such as in rivers and lakes; a volume of one cubic decametre (dam3) is equivalent to a capacity of one megalitre (ML). One technical atmosphere is the pressure of one decameter of water. Also, the are (a), a metric unit for land area, is equal to one square decametre (dam2). See also *Orders of magnitude (length) The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shevchenkove, Shevchenkove Raion
Shevchenkove ( uk, Шевченкове, ) is an urban-type settlement in Ukraine in Kupiansk Raion, Kharkiv Oblast. It hosts the administration of Shevchenkove settlement hromada, one of the hromadas of Ukraine. Population: The main railway station in Schevchenkove is Schevchenkove-South. History It started in 1896 as a village named Bulacelovka after the owner of that land, Bulacel. It was located in Kharkov Governorate of the Russian Empire. A local newspaper is published here since February 1935. During World War II it was under German occupation from February 1942 to February 1943. Shevchenkove has been considered an urban-type settlement since 1957.Шевченково // Большая Советская Энциклопедия. / под ред. А. М. Прохорова. 3-е изд. том 29. М., «Советская энциклопедия», 1978. In January 1989 the population was 7,856 people, by January 2013 the population was 7,100 people, and by Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ukrainian Academy Of Sciences
The National Academy of Sciences of Ukraine (NASU; uk, Національна академія наук України, ''Natsional’na akademiya nauk Ukrayiny'', abbr: NAN Ukraine) is a self-governing state-funded organization in Ukraine that is the main center of development of science and technology by coordinating a system of research institutes in the country. It is the main research oriented organization along with the five other academies in Ukraine specialized in various scientific disciplines. NAS Ukraine consists of numerous departments, sections, research institutes, scientific centers and various other supporting scientific organizations. The Academy reports on the annual basis to the Cabinet of Ministers of Ukraine. The presidium of the academy is located at vulytsia Volodymyrska, 57, across the street from the Building of Pedagogical Museum, which was used to host the Central Council during the independence period of 1917-18. In 1919–1991 it was a republ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometrical Configuration Of The UTR-2 Radio Telescope
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a '' geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geometri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Arm Of UTR-2 Radio Telescope Phased Array Antenna
West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth. Etymology The word "west" is a Germanic word passed into some Romance languages (''ouest'' in French, ''oest'' in Catalan, ''ovest'' in Italian, ''oeste'' in Spanish and Portuguese). As in other languages, the word formation stems from the fact that west is the direction of the setting sun in the evening: 'west' derives from the Indo-European root ''*wes'' reduced from ''*wes-pero'' 'evening, night', cognate with Ancient Greek ἕσπερος hesperos 'evening; evening star; western' and Latin vesper 'evening; west'. Examples of the same formation in other languages include Latin occidens 'west' from occidō 'to go down, to set' and Hebrew מַעֲרָב maarav 'west' from עֶרֶב erev 'evening'. Navigation To go west using a compass for navigation (in a place where magnetic north is the same dire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipole Antenna
In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods. The driving current from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the two halves of the antenna. Each side of the feedline to the transmitter or receiver is connected to one of the conductors. This contrasts with a monopole antenna, which consists of a single rod or conductor with one side of the feedline connected to it, and the other side connected to some type of ground. A common example of a dipole is the "rabbit ears" television antenna found on broadcast te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balun
A balun (from "balanced to unbalanced", originally, but now dated from "balancing unit") is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line. A balun can take many forms and may include devices that also transform impedances but need not do so. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. Common-mode chokes are also used as baluns and work by eliminating, rather than rejecting, common mode signals. Types of balun Classical transformer type In classical transformers, there are two electrically separate windings of wire coils around the transformer's core. The advantage of transformer-type over other types of balun is that the electrically separate windings for input and output allow these baluns to connect circuits whose ground-level voltages are subject to ground loops or are otherwise electrically incompatible; for that reason th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jansky
The jansky (symbol Jy, plural ''janskys'') is a non- SI unit of spectral flux density, or spectral irradiance, used especially in radio astronomy. It is equivalent to 10−26 watts per square metre per hertz. The ''flux density'' or ''monochromatic flux'', , of a source is the integral of the spectral radiance, , over the source solid angle: :S = \iint\limits_\text B(\theta,\phi) \,\mathrm\Omega. The unit is named after pioneering US radio astronomer Karl Guthe Jansky and is defined as :1~\mathrm = 10^~\mathrm\mathrm\mathrm ( SI) :1~\mathrm = 10^~\mathrm\mathrm\mathrm\mathrm ( cgs). Since the jansky is obtained by integrating over the whole source solid angle, it is most simply used to describe point sources; for example, the Third Cambridge Catalogue of Radio Sources (3C) reports results in janskys. * For extended sources, the surface brightness is often described with units of janskys per solid angle; for example, far-infrared (FIR) maps from the IRAS satellite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
URAN
Uran is a coastal town and part of Navi Mumbai, Maharashtra state in Konkan division. It lies in the Raigad district, east of Mumbai across the Dharamtar Creek. Uran is primarily a fishing and agriculture village, which has developed into the special economic zone of Uran. The primary languages spoken are Agri and Koli which is a dialect of Marathi-Konkani. History The city name is derived from the Hindu goddess Uranavati. It was called Uruvan during the rule of Madhavrao I, the fourth Peshwa of the Maratha Empire. Later, the area was named Uran by the Portuguese and Ooran by the British. Many Indian dynasties have ruled the area. In early history, these included the Maurya Empire, Sātavāhana Empire, Western Kshatrapas, Vākāṭaka Empire, Chalukyas, and Yadavas. The area around Mumbai, including Uran, was under Portuguese and British rule in the 16th to 19th centuries. Uran was subject to the Maratha princely states in the Maharashtra. Uran was once ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VLBI
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes. Data received at each antenna in the array include arrival times from a local atomic clock, such as a hydrogen maser. At a later time, the data are correlated with data from other antennas that recorded the same radio signal, to produce the resulting image. The resolution achievable using interferometry is proportional to the observing frequency. The VLBI technique enables the distance between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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