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Echelon Formation
An echelon formation () is a (usually military) formation in which its units are arranged diagonally. Each unit is stationed behind and to the right (a "right echelon"), or behind and to the left ("left echelon"), of the unit ahead. The name of the formation comes from the French word échelon, meaning a rung of a ladder, which describes the shape that this formation has when viewed from above or below. Military formation Use of the formation dates back to ancient infantry and cavalry warfare, as an alternative to column, line-abreast, or phalanx (box) formations. One of its earliest uses was at the Battle of Leuctra, when the Thebans attacked the Spartan right with a column 48 men deep while their weaker center and right were repelled. The echelon formation may have been used by Hannibal at the Battle of Cannae, Alexander the Great at the Battle of Gaugamela, Frederick II of Prussia, and the Confederate army at the Battle of Gettysburg. The tactic still persists and is r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tank
A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; their main armament is often mounted within a turret. They are a mainstay of modern 20th and 21st century ground forces and a key part of combined arms combat. Modern tanks are versatile mobile land weapons platforms whose main armament is a large- calibre tank gun mounted in a rotating gun turret, supplemented by machine guns or other ranged weapons such as anti-tank guided missiles or rocket launchers. They have heavy vehicle armour which provides protection for the crew, the vehicle's munition storage, fuel tank and propulsion systems. The use of tracks rather than wheels provides improved operational mobility which allows the tank to overcome rugged terrain and adverse conditions such as mud and ice/snow better than wheele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echelon Faults
Echelon may refer to: * A level formation ** A level or rank in an organization, profession, or society ** A military sub-subunit smaller than a company but larger than a platoon ** Echelon formation, a step-like arrangement of units * ECHELON, a worldwide electronic intelligence-gathering operation, within the UKUSA Agreement, mainly for industry espionage Places * Echelon, New Jersey Sciences * En echelon veins, geological feature * Row echelon form, in mathematics, a kind of matrix Arts * Echelon (band), a four-piece band hailing from Essex, England * The Echelon, fanbase of the band Thirty Seconds to Mars Thirty Seconds to Mars (commonly stylized as 30 Seconds to Mars) is an American Rock music, rock band from Los Angeles, California, formed in 1998. The band consists of brothers Jared Leto (lead vocals, guitar, bass, keyboards) and Shannon Let ..., named after a song on their debut album. * ''Echelons'' (album) Games * ''Echelon'' (1987 video game), a space flig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V Formation
A V formation is a symmetric V- or Chevron (insignia), chevron-shaped Formation flying, flight formation. In nature, it occurs among goose, geese, swans, ducks, and other bird migration, migratory birds while in human aviation it is used mostly in military aviation, Air show, air shows, and occasionally commercial aviation. Flying in the V formation is thought by some to improve energy efficiency. Others hypothesize that it is the formation that most reliably allows a flock of large birds to fly very close together without any member of the flock being disturbed by the vortices of a bird flying ahead, while at the same time having the most favorable conditions for the optical perceptions to maintain the flight formation. Usually, large birds fly in this formation. V formations are thought to improve the fuel efficiency of aircraft. Aerodynamics The V formation possibly improves the efficiency of flying birds, particularly over long Bird migration, migratory routes. It is hypoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Migration
Bird migration is a seasonal movement of birds between breeding and wintering grounds that occurs twice a year. It is typically from north to south or from south to north. Animal migration, Migration is inherently risky, due to predation and mortality. The Arctic tern holds the long-distance migration record for birds, travelling between Arctic breeding grounds and the Antarctic each year. Some species of Procellariiformes, tubenoses, such as albatrosses, circle the Earth, flying over the southern oceans, while others such as Manx shearwaters migrate between their northern breeding grounds and the southern ocean. Shorter migrations are common, while longer ones are not. The shorter migrations include altitudinal migrations on mountains, including the Andes and Himalayas. The timing of migration seems to be controlled primarily by changes in day length. Migrating birds navigate using celestial cues from the Sun and stars, the Earth's magnetic field, and mental maps. Histor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duck
Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group (the group of all descendants of a single common ancestral species), since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water. Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules and coots. Etymology The word ''duck'' comes from Old English 'diver', a derivative of the verb 'to duck, bend down low as if to get under something, or dive', because of the way many species in the dabbling duck group feed by upending; compare with Dutch language, Dutch and German language, German 'to dive'. This word replaced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goose
A goose (: geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (grey geese and white geese) and '' Branta'' (black geese). Some members of the Tadorninae subfamily (e.g., Egyptian goose, Orinoco goose) are commonly called geese, but are not considered "true geese" taxonomically. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are smaller. The term "goose" may refer to such bird of either sex, but when paired with "gander", "goose" refers specifically to a female one ("gander" referring to a male). Young birds before fledging are called goslings. The collective noun for a group of geese on the ground is a gaggle; when in flight, they are called a skein, a team, or a wedge; when flying close together, they are called a plump. Etymology The word "goose" is a direct descendant of Proto-Indo-European ''*ǵʰh₂éns''. In Germanic lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birdwatching
Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device such as binoculars or a telescope, by listening for bird sounds, watching public webcams, or by viewing smart bird feeder cameras. Most birdwatchers pursue this activity for recreational or social reasons, unlike ornithologists, who engage in the study of birds using formal scientific methods. Birding, birdwatching, and twitching The first recorded use of the term ''birdwatcher'' was in 1712 by William Oldsworth. The term ''birding'' was also used for the practice of ''fowling'' or hunting with firearms as in Shakespeare's '' The Merry Wives of Windsor'' (1602): "She laments sir... her husband goes this morning a-birding." The terms ''birding'' and ''birdwatching'' are today used by some interchangeably, although some participants prefer ''birding'', partly because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
En Echelon1
EN or En or en may refer to: Businesses * Bouygues (stock symbol EN) * Island Rail Corridor, formerly known as the Esquimalt and Nanaimo Railway (reporting mark EN) * Euronews, a news television and internet channel Language and writing * N, 14th letter of the Roman alphabet * EN, a mark in Sumerian cuneiform script for a High priest or Priestess (meaning "lord", or "priest") *En (digraph) /‹en›/, a phoneme *En (Cyrillic), 15th letter of the Cyrillic alphabet *En (typography), a unit of typographical width ** Dash#En dash /en dash/, a dash of length 1 en * En language, a language spoken in northern Vietnam *English language (ISO language code: en) Organisations * Eastern National, a US organization providing educational products to National Park visitors * English Nature, a former UK government conservation agency * Envirolink Northwest, an environmental organization in England Religion * En (deity) in Albanian mythology Science and technology * Engineer * E''n'' (Lie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riot Police
Riot police are police who are organized, deployed, trained or equipped to confront crowds, protests or riots. Riot police may be regular police officers who act in the role of riot police in particular situations, or they may be separate units organized within or in parallel to regular police forces. Riot police are used in a variety of different situations and purposes. They may be employed to control riots as their name suggests, to disperse or control crowds, to maintain public order or discourage criminality, or to protect people or property. The militarization of modern police has brought militaristic riot gear and new technologies that allow for their duties to expand above normal police duties. Riot gear Riot police often use special equipment called riot gear to help protect themselves and for offensive use in riot control. Riot gear typically includes personal armor, batons, tactical shield, riot shields, and riot helmets. Many riot police teams also deploy spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leapfrogging (infantry)
Bounding overwatch (also known as leapfrogging, moving overwatch, or the buddy system) is a military tactic of alternating movement of coordinated units to allow, if necessary, suppressive fire in support of offensive forward "fire and movement" or defensive " center peel" disengagement. As members of a unit (element to platoon level) take an overwatch posture, other members advance to cover; these two groups continually switch roles as they close with the enemy. This process may be done by "leapfrogging" with fireteams, but is usually done within fireteams along a squad/platoon battle line to simulate an overwhelming movement towards the enemy and make it more difficult for the enemy to distinguish specific targets. This military tactic takes continuous training and focused coordination to be effectively practiced on the modern battlefield. It was first developed in World War II, when the prevalence of man-portable automatic weapons made suppressing fire possible. Example of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platoon
A platoon is a Military organization, military unit typically composed of two to four squads, Section (military unit), sections, or patrols. Platoon organization varies depending on the country and the Military branch, branch, but a platoon can be composed of 20–50 troops, although specific platoons may range from 10 to 100 people. A platoon is typically the smallest military unit led by a Officer (armed forces), commissioned officer. The platoon leader is usually a junior officer—a Second lieutenant, second or first lieutenant or an equivalent rank. The officer is usually assisted by a platoon sergeant. Rifle platoons normally consist of a small platoon headquarters and three or four sections (Commonwealth) or squads (United States). In some armies, platoon is used throughout the branches of the army. In a few armies, such as the French Army, a platoon is specifically a cavalry unit, and the infantry use "section" as the equivalent unit. A unit consisting of several platoon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
