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Standard Frequency And Time Signal Service
Standard frequency and time signal service (short: SFTS) is, according to Article 1.53 of the International Telecommunication Union, International Telecommunication Union's (ITU) ITU Radio Regulations, Radio Regulations (RR),ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.53, definition: ''standard frequency and time signal service'' "A radiocommunication service for scientific, technical and other purposes, providing the transmission of specified frequencies, time signals, or both, of stated high precision, intended for general reception". Classification In accordance with ''ITU Radio Regulations'' (article 1) variations of this ''radiocommunication service'' are classified as follows: Standard frequency and time signal service (article 1.53) * Standard frequency and time signal-satellite service In general this ''radiocommunication service '' uses radio stations as follows: *Standard frequency and time signal stations (article 1.95) Standard freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dcf77
DCF77 is a German longwave time signal and standard-frequency radio station. It started service as a standard-frequency station on 1 January 1959. In June 1973, date and time information was added. Its primary and backup transmitter are located at in Mainflingen, about south-east of Frankfurt am Main, Germany. The transmitter generates a nominal power of 50 kW, of which about 30 to 35 kW can be radiated via a T-antenna. DCF77 is controlled by the ''Physikalisch-Technische Bundesanstalt'' (PTB), Germany's national physics laboratory and transmits in continuous operation (24 hours). It is operated by ''Media Broadcast GmbH'' (previously a subsidiary of ''Deutsche Telekom AG''), on behalf of the PTB. With Media Broadcast GmbH, a temporal transmission availability of at least 99.7% per year or under 26.28 hours of annual downtime has been agreed upon. Most service interruptions are short-term disconnections of under two minutes. Longer lasting transmission se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio De Janeiro
Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the Americas, sixth-most-populous city in the Americas. Founded in 1565 by the Portuguese people, Portuguese, the city was initially the seat of the Captaincy of Rio de Janeiro, a domain of the Portuguese Empire. In 1763, it became the capital of the State of Brazil, a List of states of the Portuguese Empire, state of the Portuguese Empire. In 1808, when the Transfer of the Portuguese Court to Brazil, Portuguese Royal Court moved to Brazil, Rio de Janeiro became the seat of the court of Queen Maria I of Portugal. She subsequently, under the leadership of her son the prince regent John VI of Portugal, raised Brazil to the dignity of a kingdom, within the United Kingdom of Portugal, Brazil and the Algarves, United Kingdom of Portugal, Brazil, and Algar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute Of Standards And Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of physical science, physical science laboratory programs that include Nanotechnology, nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Naval Observatory
The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains the country's leading facility for astronomical and timing data. The observatory is located in Northwest Washington, D.C. at the northwestern end of Embassy Row. It is among the few pre-20th century astronomical observatories located in an urban area. In 1893, in an effort to escape light pollution, it was relocated from Foggy Bottom near the city's center, to its Northwest Washington, D.C. location. The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the moons of Mars. Its achievements include providing data for the first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrier Signal
In telecommunications, a carrier wave, carrier signal, or just carrier, is a periodic waveform (usually sinusoidal) that conveys information through a process called ''modulation''. One or more of the wave's properties, such as amplitude or frequency, are modified by an information bearing signal, called the ''message signal'' or ''modulation signal''. The carrier frequency is usually much higher than the message signal frequency; this is because it is usually impractical to transmit signals with low frequencies over long distances (due to attenuation). The purpose of the carrier is usually either to transmit the information through space as an electromagnetic wave (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by frequency division multiplexing (as in a cable television system). The term originated in radio communication, where the carrier wave creates the waves which carry the information (modul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standardization
Standardization (American English) or standardisation (British English) is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization can help maximize compatibility, interoperability, safety, repeatability, efficiency, and quality. It can also facilitate a normalization of formerly custom processes. In social sciences, including economics, the idea of ''standardization'' is close to the solution for a coordination problem, a situation in which all parties can realize mutual gains, but only by making mutually consistent decisions. Divergent national standards impose costs on consumers and can be a form of non-tariff trade barrier. History Early examples Standard weights and measures were developed by the Indus Valley civilization.Iwata, Shigeo (2008), "Weights and Measures in the Indus Valley", ''Encyclopaedia of the History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events (or the intervals between them), and to quantify rates of change of quantities in material reality or in the qualia, conscious experience. Time is often referred to as a fourth dimension, along with Three-dimensional space, three spatial dimensions. Time is one of the seven fundamental physical quantities in both the International System of Units (SI) and International System of Quantities. The SI base unit of time is the second, which is defined by measuring the electronic transition frequency of caesium atoms. General relativity is the primary framework for understanding how spacetime works. Through advances in both theoretical and experimental investigations of spacetime, it has been shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocommunication Service
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ottawa, Ontario
Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the core of the Ottawa–Gatineau census metropolitan area (CMA) and the National Capital Region (Canada), National Capital Region (NCR). Ottawa had a city population of 1,017,449 and a metropolitan population of 1,488,307, making it the list of the largest municipalities in Canada by population, fourth-largest city and list of census metropolitan areas and agglomerations in Canada, fourth-largest metropolitan area in Canada. Ottawa is the political centre of Canada and the headquarters of the federal government. The city houses numerous List of diplomatic missions in Ottawa, foreign embassies, key buildings, organizations, and institutions of Government of Canada, Canada's government; these include the Parliament of Canada, the Supreme Court of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHU (radio Station)
CHU is the call sign of a shortwave time signal radio station operated by the Institute for National Measurement Standards of the National Research Council. CHU's signal is used for continuous dissemination of official Canadian government time signals, derived from atomic clocks. History Radio time signals allowed accurate and rapid distribution of time signals beyond the range of the telegraph or visual signals. This was of particular value in surveying remote areas, where time signals allowed accurate determination of longitude. In the summer of 1914, a survey party at Quinze Dam in the Ottawa River watershed attempted to receive time signals transmitted from Kingston; however, signals were not resolvable and the time signal from NAA in Arlington, Virginia was used instead.Malcolm M. Thomson, ''The Beginning of the Long Dash: A History of Timekeeping in Canada'', University of Toronto Press, 1978, ,1 Chapter 6 The station was started in 1923 by the Dominion Observatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It comprises an area of , and its population was estimated at 29 million in 2022. The capital and largest urban agglomeration is the city of Caracas. The continental territory is bordered on the north by the Caribbean Sea and the Atlantic Ocean, on the west by Colombia, Brazil on the south, Trinidad and Tobago to the north-east and on the east by Guyana. Venezuela is a presidential republic consisting of States of Venezuela, 23 states, the Venezuelan Capital District, Capital District and Federal Dependencies of Venezuela, federal dependencies covering Venezuela's offshore islands. Venezuela is among the most urbanized countries in Latin America; the vast majority of Venezuelans live in the cities of the north and in the capital. The territory o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
