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Ionosonde Juliusruh
The Ionosonde Juliusruh is a facility of the institute for atmospheric physics near Juliusruh in northeastern Germany for sounding the ionosphere with radar systems in the short wave range (frequencies between 1 MHz and 30 MHz). The landmark of the station is a 70 metre high grounded free standing steel framework tower, which was built in 1960/61 and which carries a cage aerial for the transmitter of the ionosonde. See also *List of 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' ... External links * http://www.ionosonde.iap-kborn.de/indexeng.htm * * http://www.skyscraperpage.com/diagrams/?b45849 {{authority control Research institutes in Germany Towers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juliusruh
Juliusruh is a village on the northern coast of the island of Rügen in northeastern Germany. Juliusruh is part of the municipality of Breege. Juliusruh and Breege combined have 821 inhabitants in an area of 15,99 km² (approx. 6 sq miles). Tourism is Juliusruh's economic mainstay. A facility for atmospheric research, the Ionosonde Juliusruh The Ionosonde Juliusruh is a facility of the institute for atmospheric physics near Juliusruh in northeastern Germany for sounding the ionosphere with radar systems in the short wave range (frequencies between 1 MHz and 30 MHz). The land ... is located nearby. Villages in Mecklenburg-Western Pomerania Towns and villages on Rügen Wittow {{VorpommernRügen-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) using a kite-supported antenna for reception. The transmitting station in Poldhu, Cornwall, used a spark-gap transmitter to produce a signal with a freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Wave
Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the High frequency, high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 metres); above the Medium frequency, medium frequency band (MF), to the bottom of the Very high frequency, VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" radio propagation, propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are limited by the visual horizon, about 64 km (40 miles). Shortwave broadcasts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cage Aerial
A cage antenna (British cage aerial) is a radio antenna where a conventional design has been augmented by replacing a single long conductor with several parallel wires, connected at their ends, and held in position by ring spacers or support struts mounted on a central mast (if any). The "cage" is either mounted around a central mast (either conducting or non-conducting) or suspended from overhead wires. Purpose A cage can improve any antenna design by replacing a single wire in any section that carries large, unbalanced (radiating) current; the only issue is whether the improvement will be substantial enough to warrant the extra effort. The multiple parallel wires electrically simulate a single fat wire, roughly equivalent to a wire with a diameter half as wide as the distance separating the cage wires, giving the modified antenna higher radiation resistance, lowered conductor resistance, and a wider bandwidth without as much weight and wind resistance as the equivalent fat wire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosonde
An ionosonde, or chirpsounder, is a special radar for the examination of the ionosphere. The basic ionosonde technology was invented in 1925 by Gregory Breit and Merle A. Tuve and further developed in the late 1920s by a number of prominent physicists, including Edward Victor Appleton. The term ''ionosphere'' and hence, the etymology of its derivatives, was proposed by Robert Watson-Watt. Components An ionosonde consists of: * A high frequency (HF) radio transmitter, automatically tunable over a wide range. Typically the frequency coverage is 0.5–23 MHz or 1–40 MHz, though normally sweeps are confined to approximately 1.6–12 MHz. * A tracking HF receiver which can automatically track the frequency of the transmitter. * An antenna with a suitable radiation pattern, which transmits well vertically upwards and is efficient over the whole frequency range used. * Digital control and data analysis circuits. The transmitter sweeps all or part of the HF frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of 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] |
Research Institutes In Germany
Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness to controlling sources of bias and error. These activities are characterized by accounting and controlling for biases. A research project may be an expansion on past work in the field. To test the validity of instruments, procedures, or experiments, research may replicate elements of prior projects or the project as a whole. The primary purposes of basic research (as opposed to applied research) are documentation, discovery, interpretation, and the research and development (R&D) of methods and systems for the advancement of human knowledge. Approaches to research depend on epistemologies, which vary considerably both within and between humanities and sciences. There are several forms of research: scientific, humanities, artistic, econom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
