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Atmospheric Noise
Atmospheric noise is radio noise, or "static", caused by natural atmospheric processes, primarily lightning discharges in thunderstorms. On a worldwide scale, there are about 40 lightning flashes per second, or lightning discharges per day. Lightning Atmospheric noise is radio noise caused by natural atmospheric processes, primarily lightning discharges in thunderstorms. It is mainly caused by cloud-to-ground flashes as the current is much stronger than that of Lightning#Cloud-to-cloud, cloud-to-cloud flashes. On a worldwide scale, 3.5 million lightning flashes occur daily. That means there are about 40 lightning flashes per second. The sum of all these lightning flashes results in atmospheric noise. It can be easily heard with any AM broadcasting, AM radio or single sideband, SSB radio receiver, receiver tuned to an unused frequency. The heard static is a combination of white noise (cumulative of distant thunderstorms) and electromagnetic interference, imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorandom Number Generator
A pseudorandom number generator (PRNG), also known as a deterministic random bit generator (DRBG), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random number generation, random numbers. The PRNG-generated sequence is not truly random, because it is completely determined by an initial value, called the PRNG's ''random seed, seed'' (which may include truly random values). Although sequences that are closer to truly random can be generated using hardware random number generators, ''pseudorandom number generators'' are important in practice for their speed in number generation and their reproducibility. PRNGs are central in applications such as simulations (e.g. for the Monte Carlo method), electronic games (e.g. for procedural generation), and cryptography. Cryptographic applications require the output not to be predictable from earlier outputs, and more cryptographically-secure pseudorandom number generator, elabora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Number Generation
Random number generation is a process by which, often by means of a random number generator (RNG), a sequence of numbers or symbols is generated that cannot be reasonably predicted better than by random chance. This means that the particular outcome sequence will contain some patterns detectable in hindsight but impossible to foresee. True random number generators can be ''Hardware random number generator, hardware random-number generators'' (HRNGs), wherein each generation is a function of the current value of a physical environment's attribute that is constantly changing in a manner that is practically impossible to model. This would be in contrast to so-called "random number generations" done by ''pseudorandom number generators'' (PRNGs), which generate numbers that only look random but are in fact predetermined—these generations can be reproduced simply by knowing the state of the PRNG. Various applications of randomness have led to the development of different methods for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Command, Control And Ocean Surveillance Center
The Naval Information Warfare Systems Command (NAVWAR), based in San Diego, California, is one of six SYSCOM Echelon II organizations within the United States Navy and is the Navy's technical authority and acquisition command for C4ISR (Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance), business information technology and space systems. Echelon II means that the organization reports to someone who, in turn, reports directly to the Chief of Naval Operations on the military side. From a civilian perspective, NAVWAR reports to the Assistant Secretary of the Navy ( RDA). The command was formerly known as Space and Naval Warfare Systems Command (SPAWAR) and was renamed in June 2019 to better align its identity with its mission. NAVWAR supports over 150 programs managed by the Program Executive Office (PEO) for Command, Control, Communications, Computers and Intelligence (C4I), as well as the programs of PEO for Enterprise Information Systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telecommunication Union
The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information and communications technology, information and communication technologies. It was established on 17 May 1865 as the International Telegraph Union, the first formal and permanent international organization. The organization significantly predates the UN, making it the oldest UN agency. Doreen Bogdan-Martin is the Secretary-General of ITU, the first woman to serve as its head. The ITU was initially aimed at helping connect Telegraphy, telegraphic networks between countries, with its mandate consistently broadening with the advent of new communications technologies; it adopted its current name in 1932 to reflect its expanded responsibilities over radio and the telephone. On 15 November 1947, the ITU entered into an agreement with the newly cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunication systems with the objective of ensuring the effective use of the spectrum. ITU is required, according to its constitution, to allocate spectrum and register frequency allocation, orbital positions and other parameters of satellites, "in order to avoid harmful interference between radio stations of different countries". The international spectrum management system is therefore based on regulatory procedures for frequency coordination, notification and registration. ITU-R has a permanent secretariat, the Radiocommunication Bureau, based at the ITU HQ in Geneva, Switzerland. The elected Director of the Bureau is Mario Maniewicz; he was first elected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features Peer review, peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2022 ''Journal Citation Reports'' (with an ascribed impact factor of 50.5), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in the autumn of 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander MacMillan (publisher), Alexander MacMillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Astronomy
Radio astronomy is a subfield of astronomy that studies Astronomical object, celestial objects using radio waves. It started in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxy, galaxies, as well as entirely new classes of objects, such as Radio galaxy, radio galaxies, quasars, pulsars, and Astrophysical maser, masers. The discovery of the cosmic microwave background radiation, regarded as evidence for the Big Bang, Big Bang theory, was made through radio astronomy. Radio astronomy is conducted using large Antenna (radio), radio antennas referred to as ''radio telescopes'', that are either used alone, or with multiple linked telescopes utilizing the techniques of Astronomical interferometer, radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a Galaxy#Isophotal diameter, D25 isophotal diameter estimated at , but only about 1,000 light-years thick at the spiral arms (more at the bulge). Recent simulations suggest that a dark matter area, also containing some visible stars, may extend up to a diameter of almost 2 million light-years (613 kpc). The Milky Way has several List of Milky Way's satellite galaxies, satellite galaxies and is part of the Local Group of galaxies, forming part of the Virgo Supercluster which is itself a component of the Laniakea Supercluster. It is estimated to contain 100–400 billion stars and at least that number of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Noise
Cosmic noise, also known as galactic radio noise, is radio-frequency electromagnetic radiation from sources outside of the Earth's atmosphere. Its characteristics are comparable to those of thermal noise. Cosmic noise occurs at frequencies above about 15 MHz when highly directional antennas are pointed toward the Sun or other regions of the sky, such as the center of the Milky Way Galaxy. Celestial objects like quasars, which are super dense objects far from Earth, emit electromagnetic waves in their full spectrum, including radio waves. The fall of a meteorite can also be heard through a radio receiver; the falling object burns from friction with the Earth's atmosphere, ionizing surrounding gases and producing radio waves. Cosmic microwave background radiation (CMBR) from outer space is also a form of cosmic noise. CMBR is thought to be a relic of the Big Bang, and pervades the space almost homogeneously over the entire celestial sphere. The bandwidth of the CMBR is wide, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holmdel, NJ
Holmdel is a township in Monmouth County, in the U.S. state of New Jersey. Located near Raritan Bay in the Raritan Valley Region, the township is a regional commercial hub of Central Jersey, home to Bell Labs and PNC Bank Arts Center, and a bedroom community of New York City in the New York Metropolitan Area. As of the 2020 U.S. census, the township's population was 17,400, an increase of 627 (+3.7%) from the 2010 census count of 16,773, which in turn reflected an increase of 992 (+6.3%) from the 15,781 counted in the 2000 census. Holmdel Township was formed by an act of the New Jersey Legislature on February 23, 1857, from portions of Raritan Township (now Hazlet).Snyder, John P''The Story of New Jersey's Civil Boundaries: 1606-1968'' Bureau of Geology and Topography; Trenton, New Jersey; 1969. p. 180. Accessed May 29, 2024. The origin of the township's name is unclear, with some sources indicating that it was named for the Holmes family, who were early settlers of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
