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Boomerang (countermeasure)
Boomerang is a gunfire locator developed by DARPA and BBN Technologies primarily for use against snipers. Boomerang is mounted on mobile vehicles such as the Humvee, Stryker, and MRAP combat vehicles. There were plans to integrate it into the Land Warrior system. Development Boomerang grew out of a program conceived by the U.S. Department of Defense in late 2003, months after the traditional combat phase of the Iraq War had ended on 1 May, at a time when it was clear that U.S. troops were increasingly at risk from a growing and aggressive insurgency. Often, troops in noisy Humvees did not know they were being shot at until someone was hit. U.S. Defense Secretary Donald Rumsfeld approached DARPA and asked for near-term solutions that could be applied to the conflict in Iraq. Rumsfeld was looking for something that did not have to be a perfect solution, but was at least better than nothing. The U.S. Army and Special Operations Command began using a limited number of French-mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boomerang 3 Gunfire Acoustic Detection System MOD 45153048
A boomerang () is a thrown tool, typically constructed with aerofoil sections and designed to spin about an axis perpendicular to the direction of its flight. A returning boomerang is designed to return to the thrower, while a non-returning boomerang is designed as a weapon to be thrown straight and is traditionally used by some Aboriginal Australians for hunting. Historically, boomerangs have been used for hunting, sport, and entertainment and are made in various shapes and sizes to suit different purposes. Although considered an Australian icon, ancient boomerangs have also been discovered in Africa, the Americas, and Eurasia. Description A boomerang is a throwing stick with aerodynamic properties, traditionally made of wood, but also of bone, horn, tusks and even iron. Modern boomerangs used for sport may be made from plywood or plastics such as ABS, polypropylene, phenolic paper, or carbon fibre-reinforced plastics. Boomerangs come in many shapes and sizes dependi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricochets
A ricochet ( ; ) is a rebound, bounce, or skip off a surface, particularly in the case of a projectile. Most ricochets are caused by accident and while the force of the deflection decelerates the projectile, it can still be energetic and almost as dangerous as before the deflection. The possibility of ricochet is one of the reasons for the common Gun safety#Be sure of the target and of what is beyond it, firearms safety rule "Never shoot at a flat, hard surface." Ricochets can occur with ''any'' caliber, but short or round ricocheting bullets may not produce the audible whine caused by tumbling irregular shapes. Ricochets are a hazard of shooting because, for as long as they retain sufficient velocity, ricocheting bullets or bullet fragments may cause collateral damage to animals, objects, or even the person who fired the shot. Variables Ricochets occur when a bullet or bullet fragment is deflected by an object rather than penetrating and becoming embedded in that object. Ricoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Equipment
United may refer to: Places * United, Pennsylvania, an unincorporated community * United, West Virginia, an unincorporated community Arts and entertainment Films * ''United'' (2003 film), a Norwegian film * ''United'' (2011 film), a BBC Two film Literature * ''United!'' (novel), a 1973 children's novel by Michael Hardcastle Music * United (band), Japanese thrash metal band formed in 1981 Albums * ''United'' (Commodores album), 1986 * ''United'' (Dream Evil album), 2006 * ''United'' (Marvin Gaye and Tammi Terrell album), 1967 * ''United'' (Marian Gold album), 1996 * ''United'' (Phoenix album), 2000 * ''United'' (Woody Shaw album), 1981 Songs * "United" (Judas Priest song), 1980 * "United" (Prince Ital Joe and Marky Mark song), 1994 * "United" (Robbie Williams song), 2000 * "United", a song by Danish duo Nik & Jay featuring Lisa Rowe Television * ''United'' (TV series), a 1990 BBC Two documentary series * ''United!'', a soap opera that aired on BBC One from 1965-19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Ranging
In land warfare, artillery sound ranging is a method of determining the coordinates of a hostile battery using data derived from the sound of its guns (or mortar or rockets) firing. The same methods can also be used to direct artillery fire at a position with known coordinates. It is an application of sound (or acoustic) location, which is location of the source of sounds that may originate in the air, on the ground or on or below the water's surface. Sound ranging was one of three methods of locating hostile artillery that rapidly developed in World War I. The others were aerial reconnaissance (visual and photographic) and flash spotting. A sound ranger used aural and stop-watch methods which first emerged before World War I. Stop-watch methods involved spotting a gun firing, measuring the bearing to it and the length of time it took the sound to arrive. Aural methods typically involved a person listening to a pair of microphones a few kilometres apart and measuring the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston Marathon Bombing
The Boston Marathon bombing was a domestic terrorist attack that took place during the annual Boston Marathon on April 15, 2013. Two terrorists, brothers Dzhokhar Tsarnaev and Tamerlan Tsarnaev, planted two homemade pressure cooker bombs, which detonated 14 seconds and apart at 2:49p.m., near the finish line of the race, killing three people and injuring hundreds of others, including 17 who lost limbs. Three days later, on April 18, Federal Bureau of Investigation (FBI) released images of two suspects. They were later identified as the Tsarnaev brothers, who were Chechen Kyrgyzstani-Americans. Following their identification, at 10:35p.m., they killed an MIT policeman. At 11:00p.m., they kidnapped a man in his car. At 12:15a.m., on April 19, the man escaped. At 12:45a.m., they had a shootout with the police in nearby Watertown, during which two officers were severely injured (one of whom, DJ Simmonds, died a year later). Tamerlan was shot several times, and his brother Dz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, clause 1 of the United States Constitution (1789). See alsTitle 10, Subtitle B, Chapter 301, Section 3001 The oldest and most senior branch of the U.S. military in order of precedence, the modern U.S. Army has its roots in the Continental Army, which was formed 14 June 1775 to fight the American Revolutionary War (1775–1783)—before the United States was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.Library of CongressJournals of the Continental Congress, Volume 27/ref> The United States Army considers itself to be a continuation of the Continental Army, and thus considers its institutional inception to be the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azimuth
An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematically, the relative position vector from an observer ( origin) to a point of interest is projected perpendicularly onto a reference plane (the horizontal plane); the angle between the projected vector and a reference vector on the reference plane is called the azimuth. When used as a celestial coordinate, the azimuth is the horizontal direction of a star or other astronomical object in the sky. The star is the point of interest, the reference plane is the local area (e.g. a circular area with a 5 km radius at sea level) around an observer on Earth's surface, and the reference vector points to true north. The azimuth is the angle between the north vector and the star's vector on the horizontal plane. Azimuth is usually measured i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevation (ballistics)
In ballistics, the elevation is the angle between the horizontal plane and the axial direction of the barrel of a gun, mortar or heavy artillery. Originally, elevation was a ''linear'' measure of how high the gunners had to physically lift the muzzle of a gun up from the gun carriage to compensate for projectile drop and hit targets at a certain distance. Until WWI Though early 20th-century firearms were relatively easy to fire, artillery was not. Before and during World War I, the only way to effectively fire artillery was plotting points on a plane. Most artillery units seldom employed their guns in small numbers. Instead of using pin-point artillery firing they used old means of " fire for effect" using artillery en masse. This tactic was employed successfully by past armies. By World War I, reasonably accurate artillery fire was possible even at long range requiring significant elevation. However, artillery tactics used in previous wars were carried on, and still had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Range Of A Projectile
In physics, a projectile launched with specific initial conditions will have a range. It may be more predictable assuming a flat Earth with a uniform gravity field, and no air resistance. The following applies for ranges which are small compared to the size of the Earth. For longer ranges see sub-orbital spaceflight. The maximum horizontal distance traveled by the projectile, neglecting air resistance, can be calculated as follows: Note that the source's y-y0 is replaced with the article's y0 : where * d is the total horizontal distance travelled by the projectile. * v is the velocity at which the projectile is launched * g is the |
Sonic Boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. A decibel is the primary unit measurement of sound. "A thunderclap is incredibly loud, producing levels between 100 and 120 dBA ( decibels A)- the equivalent of standing near a jet during take-off." The crack of a supersonic bullet passing overhead or the crack of a bullwhip are examples of a sonic boom in miniature. Sonic booms due to large supersonic aircraft can be particularly loud and startling, tend to awaken people, and may cause minor damage to some structures. This led to prohibition of routine supersonic flight overland. Although they cannot be completely prevented, research suggests that with careful shaping of the vehicle, the nuisance due to the sonic booms may be reduced to the point that overland supersonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzzle Blast
A muzzle blast is an explosive shockwave created at the muzzle of a firearm during shooting. Before a projectile leaves the gun barrel, it obturates the bore and "plugs up" the pressurized gaseous products of the propellant combustion behind it, essentially containing the gases within a closed system as a neutral element in the overall momentum of the system's physics. However, when the projectile exits the barrel, this functional seal is removed and the highly energetic bore gases are suddenly free to exit the muzzle and rapidly expand in the form of a supersonic shockwave (which can be often fast enough to momentarily overtake the projectile and affect its flight dynamics), thus creating the muzzle blast. The muzzle blast is often broken down into two components: an auditory component and a non-auditory component. The auditory component is the loud "Bang!" sound of the gunshot, and is important because it can cause significant hearing loss to surrounding personnel and als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, and radio and television broadcasting. They are also used in computers for recording voice, speech recognition, VoIP, and for other purposes such as ultrasonic sensors or knock sensors. Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; the condenser microphone, which uses the vibrating diaphragm as a capacitor plate; and the contact microphone, which uses a crystal of piezoelectric material. Microphones typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
