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Fernmeldeturm Berlin
The Fernmeldeturm Berlin (Telecommunications Tower Berlin) is a telecommunication tower located atop the Schäferberg hill in Berlin- Wannsee. The tower was built between 1961 and 1964, and is not open to the public. Owner and operator of the site is Deutsche Funkturm (DFMG), a subsidiary of Deutsche Telekom. The Fernmeldeturm Berlin is tall, and its steel-reinforced concrete shaft extends to a height of . Between in elevation, the tower houses six floors for technical equipment. This currently consists of transmitters for DVB-T digital television, analog FM radio, and newer Digital radio, DAB and DMB digital radio. From 1964 to the early nineties, the tower was used to implement two over-the-horizon radio links to the rest of West Germany. The city of Berlin was geographically isolated, so unusual means were necessary to bridge the distance. One such link used bundled arrays of directional antennas mounted near the top to establish a near-line-of sight connection at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin - Fernmeldeturm Auf Dem Schäferberg - 2013
Berlin ( ; ) is the capital and largest city of Germany, by both area and population. With 3.66 million inhabitants, it has the highest population within its city limits of any city in the European Union. The city is also one of the states of Germany, being the third smallest state in the country by area. Berlin is surrounded by the state of Brandenburg, and Brandenburg's capital Potsdam is nearby. The urban area of Berlin has a population of over 4.6 million and is therefore the most populous urban area in Germany. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's second-largest metropolitan region after the Rhine-Ruhr region, as well as the fifth-biggest metropolitan region by GDP in the European Union. Berlin was built along the banks of the Spree river, which flows into the Havel in the western borough of Spandau. The city includes lakes in the western and southeastern boroughs, the largest of which is Müggelsee. About one-third ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropospheric Scatter
Tropospheric scatter, also known as troposcatter, is a method of communicating with microwave radio signals over considerable distances – often up to and further depending on frequency of operation, equipment type, terrain, and climate factors. This method of propagation uses the tropospheric scatter phenomenon, where radio waves at UHF and SHF frequencies are randomly scattered as they pass through the upper layers of the troposphere. Radio signals are transmitted in a narrow beam aimed just above the horizon in the direction of the receiver station. As the signals pass through the troposphere, some of the energy is scattered back toward the Earth, allowing the receiver station to pick up the signal. Normally, signals in the microwave frequency range travel in straight lines, and so are limited to '' line-of-sight'' applications, in which the receiver can be 'seen' by the transmitter. Communication distances are limited by the visual horizon to around . Troposcatter allows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buildings And Structures In Steglitz-Zehlendorf
A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for a wide number of factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, monument, prestige, and aesthetic reasons. To better understand the term ''building'' compare the list of nonbuilding structures. Buildings serve several societal needs – primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical division of the :Human habitats, human habitat (a place of comfort and safety) and the ''outside'' (a place that at times may be harsh and harmful). Ever since the first cave paintings, buildings have also become objects or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tallest Towers
Several extant building fulfill the engineering definition of a tower: "a tall human structure, always taller than it is wide, for public or regular operational access by humans, but not for living in or office work, and are ''self-supporting'' or ''free-standing'', which means no guy-wires for support." This definition excludes continuously habitable buildings and skyscrapers as well as radio and TV masts. Also excluded because they are not designed for public or regular operational access are bridge towers or pylons, wind turbines, chimneys, transmission towers, sculptures and most large statues and obelisks. Towers are most often built to use their height for various purposes, and can stand alone or as part of a larger structure. Some common purposes are for telecommunications, and as a viewing platform. The Tokyo Skytree, completed in February 2012, is , making it the tallest tower, and third-tallest free-standing structure in the world. Entirely self-supported towers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (radio)
In radio engineering, an antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified. Antennas are essential components of all radio equipment. An antenna is an array of conductors ( elements), electrically connected to the receiver or transmitter. Antennas can be designed to transmit and receive radio waves in all horizontal directions equally ( omnidirectional antennas), or preferentially in a particular direction ( directional, or high-gain, or “beam” antennas). An antenna may include components not conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Radio Mondiale
Digital Radio Mondiale (DRM; ''mondiale'' being Italian and French for "worldwide") is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting—particularly shortwave—and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using xHE-AAC audio coding format. Various other MPEG-4 and Opus codecs are also compatible, but the standard now specifies xHE-AAC. Digital Radio Mondiale is also the name of the international non-profit consortium that has designed the platform and is now promoting its introduction. Radio France Internationale, TéléDiffusion de France, BBC World Service, Deutsche Welle, Voice of America, Telefunken (now Transradio) and Thomcast (now Ampegon) took part at the formation of the DRM consortium. The principle of DRM is that bandwidth is the limiting factor, and com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Wave
Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the daytime, reception is usually limited to more local stations, though this is dependent on the signal conditions and quality of radio receiver used. Improved signal propagation at night allows the reception of much longer distance signals (within a range of about 2,000 km or 1,200 miles). This can cause increased interference because on most channels multiple transmitters operate simultaneously worldwide. In addition, amplitude modulation (AM) is often more prone to interference by various electronic devices, especially power supplies and computers. Strong transmitters cover larger areas than on the FM broadcast band but require more energy and longer antennas. Digital modes are possible but have not reached momentum yet. MW was the main radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Network
A cellular network or mobile network is a communication network where the link to and from end nodes is wireless. The network is distributed over land areas called "cells", each served by at least one fixed-location transceiver (typically three cell sites or base transceiver stations). These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell. When joined together, these cells provide radio coverage over a wide geographic area. This enables numerous portable transceivers (e.g., mobile phones, tablets and laptops equipped with mobile broadband modems, pagers, etc.) to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabolic Dish
A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis. The parabolic reflector transforms an incoming plane wave travelling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis. Parabolic reflectors are used to collect energy from a distant source (for example sound waves or incoming star light). Since the principles of reflection are reversible, parabolic reflectors can also be used to collimate radiation from an isotropic source into a parallel beam. In optics, parabolic mirrors are used to gather light in reflecting telescopes and solar furnaces, and project a beam of light in f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fernsehturm Stuttgart
Fernsehturm Stuttgart ( en, Stuttgart TV Tower) is a telecommunications tower in Stuttgart, Germany. It was the first telecommunications tower in the world constructed from reinforced concrete, and it is the prototype for many such towers worldwide. Although controversial at first, it quickly became a well known landmark of Stuttgart and a tourist attraction. Location The tower is located on the hill '' Hoher Bopser'' (elevation 483 meters) in the southern Stuttgart borough of Degerloch. From the observation decks there is a view of Stuttgart, from the forests and vineyards in and around Stuttgart to the Swabian Jura and the Black Forest. History The tower's construction was controversial – critics opposed the new building method and its costs; a simple 200-meter antenna array would have cost just 200,000 DM. Construction began on 10 January 1954 and continued for 20 months. This made it the first telecom tower in the world built with reinforced concrete. The construction cos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Loading
Wind engineering is a subset of mechanical engineering, structural engineering, meteorology, and applied physics that analyzes the effects of wind in the natural and the built environment and studies the possible damage, inconvenience or benefits which may result from wind. In the field of engineering it includes strong winds, which may cause discomfort, as well as extreme winds, such as in a tornado, hurricane or heavy storm, which may cause widespread destruction. In the fields of wind energy and air pollution it also includes low and moderate winds as these are relevant to electricity production and dispersion of contaminants. Wind engineering draws upon meteorology, fluid dynamics, mechanics, geographic information systems, and a number of specialist engineering disciplines, including aerodynamics and structural dynamics. The tools used include atmospheric models, atmospheric boundary layer wind tunnels, and computational fluid dynamics models. Wind engineering involves, among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabolic Reflector
A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis. The parabolic reflector transforms an incoming plane wave travelling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis. Parabolic reflectors are used to collect energy from a distant source (for example sound waves or incoming star light). Since the principles of reflection are reversible, parabolic reflectors can also be used to collimate radiation from an isotropic source into a parallel beam. In optics, parabolic mirrors are used to gather light in reflecting telescopes and solar furnaces, and project a beam of li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
