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List Of Cosmic Microwave Background Experiments
This list is a compilation of experiments measuring the cosmic microwave background (CMB) radiation anisotropies and polarization since the first detection of the CMB by Penzias and Wilson in 1964. There have been a variety of experiments to measure the CMB anisotropies and polarization since its first observation in 1964 by Penzias and Wilson. These include a mix of ground-, balloon- and space-based receivers. Some notable experiments in the list are COBE, which first detected the temperature anisotropies of the CMB, and showed that it had a black body spectrum; DASI, which first detected the polarization signal from the CMB; CBI, which made high-resolution observations and obtained the first E-mode polarization spectrum; WMAP; and the Planck spacecraft, which has produced the highest resolution all-sky map to-date of both the temperature anisotropies and polarization signals. Current scientific goals for CMB observation include precise measurement of gravitational lensin ... [...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] |
Archeops Gondola At Launch
Archeops was a balloon-borne instrument dedicated to measuring the Cosmic microwave background In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all spac ... (CMB) temperature anisotropies. The study of this radiation is essential to obtain precise information on the evolution of the Universe: density, Hubble's law#Measured values of the Hubble constant, Hubble constant, Age of the universe, age of the Universe, etc. To achieve this goal, measurements were done with devices cooled down at 100mK temperature placed at the focus of a warm telescope. To avoid atmospheric disturbance the whole apparatus is placed on a gondola below a helium balloon that reaches 40 km altitude. Archeops has four bands in the millimeter domain (143, 217, 353 and 545 GHz) with a high angular resolution (about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Radiometer For Cosmology, Astrophysics, And Diffuse Emission
Arcade most often refers to: * Arcade game, a coin-operated game machine ** Arcade cabinet, housing which holds an arcade game's hardware ** Arcade system board, a standardized printed circuit board * Amusement arcade, a place with arcade games * Arcade (architecture), a series of adjoining arches * Shopping mall, one or more buildings forming a complex of shops, also sometimes called a shopping arcade Arcade or The Arcade may also refer to: Places Greece *Arcades (Crete), a town and city-state of ancient Crete, Greece Italy * Arcade, Italy, a town and commune in the region of Veneto United States * Arcade Building (Asheville, North Carolina) * Arden-Arcade, California * Arcade, Georgia, a city in Jackson County * Arcade (village), New York * Arcade (town), New York * The Arcade (Oak Bluffs, Massachusetts), a historic site in Oak Bluffs, Massachusetts * The Arcade (Providence, Rhode Island), a historic shopping center * Arcade, Texas Arts and entertainment Books and comic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARCADE Balloon
Arcade most often refers to: * Arcade game, a coin-operated game machine ** Arcade cabinet, housing which holds an arcade game's hardware ** Arcade system board, a standardized printed circuit board * Amusement arcade, a place with arcade games * Arcade (architecture), a series of adjoining arches * Shopping mall, one or more buildings forming a complex of shops, also sometimes called a shopping arcade Arcade or The Arcade may also refer to: Places Greece *Arcades (Crete), a town and city-state of ancient Crete, Greece Italy * Arcade, Italy, a town and commune in the region of Veneto United States * Arcade Building (Asheville, North Carolina) * Arden-Arcade, California * Arcade, Georgia, a city in Jackson County * Arcade (village), New York * Arcade (town), New York * The Arcade (Oak Bluffs, Massachusetts), a historic site in Oak Bluffs, Massachusetts * The Arcade (Providence, Rhode Island), a historic shopping center * Arcade, Texas Arts and entertainment Books and comics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately wide varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System. Biogeographically, the Antarctic realm is one of eight biogeographic realms of Earth's land surface. Geography As defined by the Antarctic Treaty System, the Antarctic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Plateau Anisotropy Chasing Experiment
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately wide varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System. Biogeographically, the Antarctic realm is one of eight biogeographic realms of Earth's land surface. Geography As defined by the Antarctic Treaty System, the Antarctic regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Pole
The South Pole, also known as the Geographic South Pole, Terrestrial South Pole or 90th Parallel South, is one of the two points where Earth's axis of rotation intersects its surface. It is the southernmost point on Earth and lies antipodally on the opposite side of Earth from the North Pole, at a distance of 12,430 miles (20,004 km) in all directions. Situated on the continent of Antarctica, it is the site of the United States Amundsen–Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole is distinct from the South Magnetic Pole, the position of which is defined based on Earth's magnetic field. The South Pole is at the centre of the Southern Hemisphere. Geography For most purposes, the Geographic South Pole is defined as the southern point of the two points where Earth's axis of rotation intersects its surface (the other being the Geographic North Pole). However, Earth's axis of rotat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S latitude), and has an average height of about . The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. Along their length, the Andes are split into several ranges, separated by intermediate depressions. The Andes are the location of several high plateaus—some of which host major cities such as Quito, Bogotá, Cali, Arequipa, Medellín, Bucaramanga, Sucre, Mérida, El Alto and La Paz. The Altiplano plateau is the world's second-highest after the Tibetan plateau. These ranges are in turn grouped into three major divisions based on climate: the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes Mountains are the highest m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon Noise
Photon noise is the randomness in signal associated with photons arriving at a detector. For a simple black body emitting on an absorber, the noise-equivalent power is given by :\mathrm^2 = 2 h^2 \nu^2 \Delta\nu \left( \frac + n^2 \right) where h is the Planck constant, \nu is the central frequency, \Delta\nu is the bandwidth, n is the occupation number and \eta is the optical efficiency. The first term is essentially shot noise whereas the second term is related to the bosonic character of photons, variously known as "Bose noise" or "wave noise". At low occupation number, such as in the visible spectrum, the shot noise term dominates. At high occupation number, however, typical of the radio spectrum, the Bose term dominates. See also * Hanbury Brown and Twiss effect * Phonon noise Phonon noise, also known as thermal fluctuation noise, arises from the random exchange of energy between a thermal mass and its surrounding environment. This energy is quantized in the form of phon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feed Horn
A feed horn (or feedhorn) is a small horn antenna used to couple a waveguide to e.g. a parabolic dish antenna or offset dish antenna for reception or transmission of microwave. A typical application is the use for satellite television reception with a satellite dish. In that case the feed horn can either be a separate part used together with e.g. a "low-noise block downconverter" (LNB), or more typically today is integrated into a "low-noise block feedhorn" (LNBF). Principle of operation The feed horn minimizes the mismatch loss between the antenna and the waveguide. If a simple open-ended waveguide would be used, without the horn, the sudden end of the conductive walls causes an abrupt impedance change at the aperture, between the wave impedance in the waveguide and the impedance of free space (see horn antenna for more details). When used with a offset, parabolic or lens antenna, the phase center of the horn is placed at the focal point of the reflector. The characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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