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Beacons
A beacon is an intentionally conspicuous device designed to attract attention to a specific location. A common example is the lighthouse, which draws attention to a fixed point that can be used to navigate around obstacles or into port. More modern examples include a variety of radio beacons that can be read on radio direction finders in all weather, and radar transponders that appear on radar displays. Beacons can also be combined with semaphoric or other indicators to provide important information, such as the status of an airport, by the colour and rotational pattern of its airport beacon, or of pending weather as indicated on a weather beacon mounted at the top of a tall building or similar site. When used in such fashion, beacons can be considered a form of optical telegraphy. For navigation Beacons help guide navigators to their destinations. Types of navigational beacons include radar reflectors, radio beacons, sonic and visual signals. Visual beacons range from s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Beacon
In navigation, a radio beacon or radiobeacon is a kind of beacon, a device that marks a fixed location and allows direction finding, direction-finding equipment to find relative Bearing (navigation), bearing. But instead of employing visible light, radio beacons transmit electromagnetic radiation in the radio wave electromagnetic spectrum, band. They are used for direction-finding systems on ships, aircraft and vehicles. Radio beacons transmitter, transmit a continuous or periodic radio signal with limited information (for example, its identification or location) on a specified radio frequency. Occasionally, the beacon's transmission includes other information, such as telemetry, telemetric or meteorological data. Radio beacons have many applications, including air and sea navigation, propagation research, robotic mapping, radio-frequency identification (RFID), near-field communication (NFC) and indoor navigation, as with real-time locating systems (RTLS) like Syledis or simulta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Beacons
In navigation, a radio beacon or radiobeacon is a kind of beacon, a device that marks a fixed location and allows direction-finding equipment to find relative bearing. But instead of employing visible light, radio beacons transmit electromagnetic radiation in the radio wave band. They are used for direction-finding systems on ships, aircraft and vehicles. Radio beacons transmit a continuous or periodic radio signal with limited information (for example, its identification or location) on a specified radio frequency. Occasionally, the beacon's transmission includes other information, such as telemetric or meteorological data. Radio beacons have many applications, including air and sea navigation, propagation research, robotic mapping, radio-frequency identification (RFID), near-field communication (NFC) and indoor navigation, as with real-time locating systems (RTLS) like Syledis or simultaneous localization and mapping (SLAM). Types Radio-navigation beacons The mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Beacon
A weather beacon is a beacon that indicates the local weather forecast in a code of colored or flashing lights. Often, a short poem or jingle accompanies the code to make it easier to remember. The beacon is usually on the roof of a tall building in a central business district, but some are attached to towers. The beacons are most commonly owned by financial services companies and television stations and are part of advertising and public relations programs. They provide a very basic forecast for the general public and not as an aid to navigation. In addition to displaying weather forecasts, some weather beacons have been used to signal victory or defeat for a professional sports home team. History Precursors In 1898 on the orders of U.S. President William McKinley, coastal warning display towers were installed along the coast of the United States. In 1936, the City Hall Square, Copenhagen#Sculptures, ''Weather Girl'' sculptures were installed in City Hall Square, Copenhagen, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Day Beacon
A day beacon (sometimes ''daybeacon'') is an unlighted nautical sea mark. A signboard identifying it is called a '' day mark''. Day beacons typically mark channels whose key points are marked by lighted buoys. They may also mark smaller navigable routes in their entirety. They are the most common navigation aid in shallow water, as they are relatively inexpensive to install and maintain. Navigation around them is similar to that around other navigation aids. Identification Lateral marking For historical reasons, there are two systems for lateral day beacons. When proceeding from open water towards harbor, marks with cylindrical topmarks or square dayboards are kept to port in both regions, but colors and numbers are reversed. When lateral beacons are paired, vessels should pass between the pairing. However, beacons are also frequently placed individually. Generally, single lateral beacons are at the inside corner of a turn. Interior or exterior placement can be determined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finder
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturally-occurring radio source, or an illicit or enemy system. Radio direction finding differs from radar in that only the direction is determined by any one receiver; a radar system usually also gives a distance to the object of interest, as well as direction. By triangulation, the location of a radio source can be determined by measuring its direction from two or more locations. Radio direction finding is used in radio navigation for ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. During the Second World War, radio direction finding was used by both sides to locate and direct aircraft, surface ships, and submarines. RDF systems can be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and the advent of much cheaper, more sophisticated, and more effective electronic navigational systems. History Ancient lighthouses Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since elevating the fire would improve visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs and promontory, prom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodrome Beacon
An aerodrome beacon, airport beacon, rotating beacon or aeronautical beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night. An aerodrome beacon is mounted on top of a towering structure, often a control tower, above other buildings of the airport. It produces flashes similar to that of a lighthouse. Airport and heliport beacons are designed in such a way to make them most effective from one to ten degrees above the horizon; however, they can be seen well above and below this peak spread. The beacon may be an omnidirectional flashing xenon strobe, or it may be an aerobeacon rotating at a constant speed which produces the visual effect of flashes at regular intervals. Flashes may be of one, two, or three alternating colors ( described below). In the United States In the United States, the Federal Aviation Administration (FAA) has established the following rules for airport beacons: Flashing rates # 24 to 30 per minute fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phryctoriae
Phryctoria () was a semaphore system used in Ancient Greece. The ''phryctoriae'' were towers built on selected mountaintops so that one tower (''phryctoria'') would be visible to the next tower (usually 20 miles away). The towers were used for the transmission of a specific prearranged message. One tower would light its flame, the next tower would see the fire, and light its own. In Aeschylus tragedy ''Agamemnon'', a slave watchman character learns the news of Troy's fall from Mycenae by carefully watching a fire beacon. Thucydides wrote that during the Peloponnesian War, the Peloponnesians who were in Corcyra were informed by night-time beacon signals of the approach of sixty Athenian vessels from Lefkada. When Cnemus attacked Salamis Island, the Salaminians informed the Athenians and asked for help by beacon-fires. Phryctoriae and Pyrseia Ιn the 2nd century BC, the Greek engineers from Alexandria, Cleoxenes () and Democletus () invented the ''pyrseia'' (). Πυρσεία f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodrome Beacon
An aerodrome beacon, airport beacon, rotating beacon or aeronautical beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night. An aerodrome beacon is mounted on top of a towering structure, often a control tower, above other buildings of the airport. It produces flashes similar to that of a lighthouse. Airport and heliport beacons are designed in such a way to make them most effective from one to ten degrees above the horizon; however, they can be seen well above and below this peak spread. The beacon may be an omnidirectional flashing xenon strobe, or it may be an aerobeacon rotating at a constant speed which produces the visual effect of flashes at regular intervals. Flashes may be of one, two, or three alternating colors ( described below). In the United States In the United States, the Federal Aviation Administration (FAA) has established the following rules for airport beacons: Flashing rates # 24 to 30 per minute fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Wall
The Great Wall of China (, literally "ten thousand Li (unit), ''li'' long wall") is a series of fortifications in China. They were built across the historical northern borders of ancient Chinese states and Imperial China as protection against Eurasian nomads, various nomadic groups from the Eurasian Steppe. The first walls date to the 7th century BC; these were joined together in the Qin dynasty. Successive dynasties expanded the wall system; the best-known sections were built by the Ming dynasty (1368–1644). To aid in defense, the Great Wall utilized watchtowers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and its status as a transportation corridor. Other purposes of the Great Wall have included border controls (allowing control of immigration and emigration, and the imposition of duties on goods transported along the Silk Road), and the regulation of trade. The collective fortifications constituting the Great Wall stret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
King You Of Zhou
King You of Zhou (795–771 BC), personal name Ji Gongsheng, was a king of the Chinese Zhou dynasty and the last from the Western Zhou dynasty. He reigned from 781 to 771 BC. History In 780 BC, a major earthquake struck Guanzhong. A soothsayer named Bo Yangfu () considered this an omen foretelling the destruction of the Zhou Dynasty. In 779 BC, a concubine named Bao Si entered the palace and came into the King You's favour. They had a son named Bofu. King You deposed and Crown Prince Yijiu. He made Bao Si the new queen and Bofu the new crown prince. Queen Shen's father, the Marquess of Shen, was furious at the deposition of his daughter and grandson Crown Prince Yijiu and mounted an attack on King You's palace with the Quanrong. King You called for his nobles using the previously abused beacons but none came. In the end, King You and Bofu were killed and Bao Si was captured. After King You died, nobles including the Marquess of Shen, the Marquess of Zeng () and supporte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
