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Télé Distribution Française
ALS162 is a French longwave time signal and standard-frequency radio station and is used for the dissemination of the Metropolitan French national legal time to the public. TéléDiffusion de France broadcast the ALS162 time signal, provided by LNE-SYRTE and LNE-LTFB time laboratories under ANFR (state body for radio frequencies) responsibility, from the Allouis longwave transmitter at 162 kHz, with a power of 800 kW. The current time signal is generated by extremely accurate caesium atomic clocks and phase-modulated on the 162 kHz ( wavelength) carrier signal in a way that is inaudible when listening to the signal using normal Longwave receivers. The ALS162 phase-modulated time signal service requires a more complex receiver than the popular German DCF77 amplitude-modulated time signal service, but the much more powerful transmitter (16 times DCF77's 50 kW) gives it a much greater range of 3,500 km. The signal transmission is almost continuous, but th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNCF
The Société nationale des chemins de fer français (, , SNCF ) is France's national State-owned enterprise, state-owned railway company. Founded in 1938, it operates the Rail transport in France, country's national rail traffic along with that of Monaco, including the TGV, on France's high-speed rail network. Its functions include operation of railway services for passengers and freight (through its subsidiaries SNCF Voyageurs and Rail Logistics Europe), as well as maintenance and signalling of rail infrastructure (SNCF#Divisions, SNCF Réseau). The railway network consists of about of route, of which are high-speed lines and electrified. About 14,000 trains are operated daily. In 2010 the SNCF was ranked 22nd in France and 214th globally on the Fortune Global 500, ''Fortune'' Global 500 list. It is the main business of the SNCF Group, which in 2020 had €30 billion of sales in 120 countries. The SNCF Group employs more than 275,000 employees in France and around the worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radian
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the centre of a circle by an Circular arc, arc that is equal in length to the radius. The unit was formerly an SI supplementary unit and is currently a dimensionless unit, dimensionless SI derived unit,: "The CGPM decided to interpret the supplementary units in the SI, namely the radian and the steradian, as dimensionless derived units." defined in the SI as 1 rad = 1 and expressed in terms of the SI base unit metre (m) as . Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing. Definition One radian is defined as the angle at the center of a circle in a plane that wikt:subtend, subtends an arc whose length equals the radius of the circle. More generally, the magnit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmitter Station
A transmitter station or transmission facility is an installation used for transmitting radio frequency signals for wireless communication, broadcasting, microwave link, mobile telephone or other purposes. Choice of location The location may be chosen to fit the coverage area and for VHF-UHF-applications Line-of-sight propagation, line of sight considerations. For lower frequencies a location with good ground conductivity is required. In case of microwave link chains, stations should be in observable ranges of each other. (see Earth bulge) Computer programmes for the terrain profile and abacs are used in addition to on site observations. Avoidance of industrial noise is also taken into consideration. Another parameter may be the government regulations concerning public health requiring a minimum distance to human habitation. The distance depends on the Effective radiated power, power and the frequency of the transmitting signal. Low power stations may be in cities; higher pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
