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Y-Gerät
The Battle of the Beams was a period early in the Second World War when bombers of the German Air Force (''Luftwaffe'') used a number of increasingly accurate systems of radio navigation for night bombing in the United Kingdom. British scientific intelligence at the Air Ministry fought back with a variety of their own increasingly effective means, involving jamming and deception signals. The period ended when the Wehrmacht moved their forces to the East in May 1941, in preparation for the attack on the Soviet Union. The idea of "beam" based navigation was developed during the 1930s, initially as a blind landing aid. The basic concept is to produce two directional radio signals that are aimed slightly to the left and right of a runway's midline. Radio operators in the aircraft listen for these signals and determine which of the two beams they are flying in. This is normally accomplished by sending Morse code signals into the two beams, to identify right and left. For bombing, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knickebein Antenna
The Battle of the Beams was a period early in the Second World War when bombers of the German Air Force (''Luftwaffe'') used a number of increasingly accurate systems of radio navigation for night bombing in the United Kingdom. British scientific intelligence at the Air Ministry fought back with a variety of their own increasingly effective means, involving jamming and deception signals. The period ended when the Wehrmacht moved their forces to the East in May 1941, in preparation for the attack on the Soviet Union. The idea of "beam" based navigation was developed during the 1930s, initially as a blind landing aid. The basic concept is to produce two directional radio signals that are aimed slightly to the left and right of a runway's midline. Radio operators in the aircraft listen for these signals and determine which of the two beams they are flying in. This is normally accomplished by sending Morse code signals into the two beams, to identify right and left. For bombing, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Blitz
The Blitz was a German bombing campaign against the United Kingdom in 1940 and 1941, during the Second World War. The term was first used by the British press and originated from the term , the German word meaning 'lightning war'. The Germans conducted mass air attacks against industrial targets, towns, and cities, beginning with raids on London towards the end of the Battle of Britain in 1940 (a battle for daylight air superiority between the Luftwaffe and the Royal Air Force over the United Kingdom). By September 1940, the Luftwaffe had lost the Battle of Britain and the German air fleets () were ordered to attack London, to draw RAF Fighter Command into a battle of annihilation.Price 1990, p. 12. Adolf Hitler and Reichsmarschall Hermann Göring, commander-in-chief of the Luftwaffe, ordered the new policy on 6 September 1940. From 7 September 1940, London was systematically bombed by the Luftwaffe for 56 of the following 57 days and nights. Most notable was a large dayligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination. The basic principles are measurements from/to electric beacons, especially * Angular directions, e.g. by bearing, radio phases or interferometry, * Distances, e.g. ranging by measurement of time of flight between one transmitter and multiple receivers or vice versa, * Distance ''differences'' by measurement of times of arrival of signals from one transmitter to multiple receivers or vice versa * Partly also velocity, e.g. by means of radio Doppler shift. Combinations of these measurement principles also are important—e.g., many radars measure range and azimuth of a target. Bearing-measurement systems These systems used some form of directional radio antenna to determine the location of a broadcast station on the ground. Conventional navigation techniques a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipole Antenna
In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods. The driving current from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the two halves of the antenna. Each side of the feedline to the transmitter or receiver is connected to one of the conductors. This contrasts with a monopole antenna, which consists of a single rod or conductor with one side of the feedline connected to it, and the other side connected to some type of ground. A common example of a dipole is the "rabbit ears" television antenna found on broadcast telev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stollberg (North Frisia)
At 43.4 metres above Normalnull, sea level, the Stollberg is the fourth highest hill in the district of Kreis Nordfriesland, North Frisia in northern Germany, after the Sandesberg near Ostenfeld (Husum), Ostenfeld (53.3 m), the Uwe Düne in the municipality of Kampen (Sylt), Kampen auf Sylt (50.2 m) and the Rantzauhöhe within the Langenberg south of the village of Leck (Nordfriesland), Leck (44.8 m). It is part of the geest (topography), geest ridge that runs westwards and was created as a so-called old moraine during the Saale glaciation and was subsequently shaped during the Weichselian glaciation. From the top of the Stollberg there is a good view over the surrounding area, both near and far. The Stollberg belongs to the municipality of Bordelum and lies immediately next to the Bundesstraße 5, B 5 federal road. In the vicinity of the hill is the Stollberg spring, which was considered holy in earlier times. In April 2002 the Ministry for the Environment, Nature and Forests in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanic Mythology
Germanic mythology consists of the body of myths native to the Germanic peoples, including Norse mythology, Anglo-Saxon mythology, and Continental Germanic mythology. It was a key element of Germanic paganism. Origins As the Germanic languages developed from Proto-Indo-European language, Germanic mythology is ultimately a development of Proto-Indo-European mythology. Archaeological remains, such as petroglyphs in Scandinavia, suggest continuity in Germanic mythology since at least the Nordic Bronze Age. Sources The earliest written sources on Germanic mythology include literature by Roman writers. This includes ''Commentaries on the Gallic War'' by Julius Caesar, ''Geographica'' by Strabo, and ''Germania'' by Tacitus. Later Latin-language sources on Germanic mythology include ''Getica'' by Jordanes, ''History of the Lombards'' by Paul the Deacon, ''Ecclesiastical History of the English People'' by Bede, ''Vita Ansgari'' by Rimbert, ''Gesta Hammaburgensis ecclesiae pontificum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Map Of Knickebein Transmitters
A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes. Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although most commonly used to depict geography, maps may represent any space, real or fictional, without regard to context or scale, such as in brain mapping, DNA mapping, or computer network topology mapping. The space being mapped may be two dimensional, such as the surface of the earth, three dimensional, such as the interior of the earth, or even more abstract spaces of any dimension, such as arise in modeling phenomena having many independent variables. Although the earliest maps known are of the heavens, geographic maps of territory have a very long tradition and exist from ancient times. The word "map" comes from the , wherein ''mappa'' meant 'napkin' or 'cloth' and ''mundi'' 'the world'. Thus, "map" became a shortened term referring to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Navigation
Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space (or on the surface of the Earth) without having to rely solely on estimated positional calculations, commonly known as "dead reckoning", made in the absence of satellite navigation or other similar modern electronic or digital positioning means. Celestial navigation uses "sights", or timed angular measurements, taken typically between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. Celestial navigation can also take advantage of measurements between celestial bodies without reference to the Earth horizon, such as when the Moon and other selected bodies are used in the practice called "lunars" or lunar distance method, used for determining precise time when time is unknown. Celestial navigation by taking sights of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrodome (aviation)
An astrodome is a hemispherical transparent dome that was installed in the cabin roof of an aircraft. Such a dome would allow a trained navigator to perform astronavigation and thereby guide the aircraft at night without the aid of land-based visual references. Astronavigation was a principal early method for attaining an aircraft's position during nighttime by referencing the stars. The practice of sighting stars using a sextant had been commonplace amongst navigators for hundreds of years aboard ships, and proved to be applicable to faster moving aircraft as well, however, the task required a 360-degree view of the horizon. By installing an astrodome, such a view could be readily achieved. The Royal Air Force (RAF) adopted astronavigation techniques into standard navigator training during the late 1930s, both the methods used and the design of the sextant were adapted to better suit the aviation environment, while many aircraft ordered by the service would be furnished with as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackout (wartime)
A blackout during war, or in preparation for an expected war, is the practice of collectively minimizing outdoor light, including upwardly directed (or reflected) light. This was done in the 20th century to prevent crews of enemy aircraft from being able to identify their targets by sight, such as during the London Blitz of 1940. In coastal regions, a shoreside blackout of city lights also helped protect ships from being seen silhouetted against the artificial light by enemy submarines farther out at sea. World War I Plans to black out British coastal towns in the event of war were drawn up in 1913 by Winston Churchill in his role as First Lord of the Admiralty; these plans were implemented on 12 August 1914, eight days after the United Kingdom had entered the war. On 1 October 1914, the Commissioner of the Metropolitan Police ordered that bright exterior lights were to be extinguished or dimmed in the London area and street lamps be partially painted out with black paint. Elsewhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Bomber Will Always Get Through
"The bomber will always get through" was a phrase used by Stanley Baldwin in a 1932 speech "A Fear for the Future" given to the British Parliament. His speech stated that contemporary bomber aircraft had the performance necessary to conduct a strategic bombing campaign that would destroy a country's cities and there was little that could be done in response. It concluded that the conduct of future wars would require one to "kill more women and children more quickly than the enemy if you want to save yourselves." At the time of the speech aircraft performance was rapidly improving and new techniques and construction methods were producing ever-larger aircraft. For a time, this resulted in a performance gap where multi-engine aircraft outperformed the single-engine fighter aircraft that would have to intercept them. This gap could be further widened through the use of night bombing, which made interception practically impossible. This state of affairs was relatively short-lived. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
