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Elevation (ballistics)
In ballistics, the elevation is the angle between the horizontal plane and the axial direction of the barrel (firearms), barrel of a gun, Mortar (weapon), mortar or heavy artillery. Originally, elevation was a ''linear'' measure of how high the gunners had to physically lift the muzzle (firearm), 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tank Gun
A tank gun is the main armament of a tank. Modern tank guns are high-velocity, large-caliber artilleries capable of firing kinetic energy penetrators, high-explosive anti-tank, and cannon-launched guided projectiles. Anti-aircraft guns can also be mounted to tanks. As the tank's primary armament, they are almost always employed in a direct fire mode to defeat a variety of ground targets at all ranges, including dug-in infantry, lightly armored vehicles, and especially other heavily armored tanks. They must provide accuracy, range, penetration, and rapid fire in a package that is as compact and lightweight as possible, to allow mounting in the cramped confines of an armored gun turret. Tank guns generally use self-contained ammunition, allowing rapid loading (or use of an autoloader). They often display a bulge in the barrel, which is a bore evacuator, or a device on the muzzle, which is a muzzle brake. History World War I The first tanks were used to break through trench d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitching Moment
In aerodynamics, the pitching moment on an airfoil is the Moment (physics), moment (or torque) produced by the aerodynamic force with respect to the aerodynamic center on the airfoil . The pitching moment on the wing of an airplane is part of the total moment that must be balanced using the lift on the horizontal stabilizer. More generally, a pitching moment is any moment acting on the pitch (aviation), pitch axis of a moving body. The Lift (force), lift on an airfoil is a distributed force that can be said to act at a point called the center of pressure. However, as angle of attack changes on a Camber (aerodynamics), cambered airfoil, there is Center of pressure (fluid mechanics)#Movement of center of pressure, movement of the center of pressure forward and aft. This makes analysis difficult when attempting to use the concept of the center of pressure. One of the remarkable properties of a Camber (aerodynamics), cambered airfoil is that, even though the center of pressure m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altitude (astronomy)
The horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane to define two angles of a spherical coordinate system: altitude and ''azimuth''. Therefore, the horizontal coordinate system is sometimes called the az/el system, the alt/az system, or the alt-azimuth system, among others. In an altazimuth mount of a telescope, the instrument's two axes follow altitude and azimuth. Definition This celestial coordinate system divides the sky into two hemispheres: The upper hemisphere, where objects are above the horizon and are visible, and the lower hemisphere, where objects are below the horizon and cannot be seen, since the Earth obstructs views of them. The great circle separating the hemispheres is called the ''celestial horizon'', which is defined as the great circle on the celestial sphere whose plane is normal to the local gravity vector (the vertical direction). In practice, the horizon can be define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MANPADS
Man-portable air-defense systems (MANPADS or MPADS) are portable shoulder-launched surface-to-air missiles. They are guided weapons and are a threat to low-flying aircraft, especially helicopters and also used against low-flying cruise missiles. These short-range missiles can also be fired from vehicles, tripods, weapon platforms, and warships. Overview MANPADS were developed in the 1950s to provide military ground forces with protection from jet aircraft. They have received a great deal of attention, partly because armed terrorist groups have used them against commercial airliners. These missiles, affordable and widely available through a variety of sources, have been used successfully over the past three decades, both in military conflicts, by militant groups, and by terrorist organizations. Twenty-five countries, including China, Iran, Poland, Russia, Sweden, the United Kingdom and the United States produce man-portable air defense systems.CRS RL31741 page 1 Possession, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guided Missile
A missile is an airborne ranged weapon capable of Propulsion, self-propelled flight aided usually by a propellant, jet engine or rocket motor. Historically, 'missile' referred to any projectile that is thrown, shot or propelled towards a target; this usage is still recognized today with any unguided jet- or rocket-propelled weapons generally described as rocket artillery. Airborne explosive devices without propulsion are referred to as shell (projectile), shells if fired by an artillery piece and Aerial bomb, bombs if dropped by an aircraft. Missiles are also generally missile guidance, guided towards specific targets termed as guided missiles or guided Rocket (weapon), rockets. Missile systems usually have five system components: targeting (warfare), targeting, guidance system, flight system, engine, and warhead. Missiles are primarily classified into different types based on firing source and target such as surface-to-surface missile, surface-to-surface, air-to-surface missi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Rangefinder
A laser rangefinder, also known as a laser telemeter or laser distance meter, is a rangefinder that uses a laser beam to determine the distance to an object. The most common form of laser rangefinder operates on the time of flight principle by sending a laser pulse in a narrow beam towards the object and measuring the time taken by the pulse to be reflected off the target and returned to the sender. Due to the high speed of light, this technique is not appropriate for high precision sub-millimeter measurements, where triangulation and other techniques are often used instead. Laser rangefinders are sometimes classified as type of handheld scannerless lidar. Pulse The pulse may be coded to reduce the chance that the rangefinder can be jammed. It is possible to use Doppler effect techniques to judge whether the object is moving towards or away from the rangefinder, and if so, how fast. Precision The precision of an instrument is correlated with the rise time, divergence, and po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire-control System
A fire-control system (FCS) is a number of components working together, usually a gun data computer, a director and radar, which is designed to assist a ranged weapon system to target, track, and hit a target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more accurately. Naval fire control Origins The original fire-control systems were developed for ships. The early history of naval fire control was dominated by the engagement of targets within visual range (also referred to as direct fire). In fact, most naval engagements before 1800 were conducted at ranges of . Even during the American Civil War, the famous engagement between and was often conducted at less than range. Rapid technical improvements in the late 19th century greatly increased the range at which gunfire was possible. Rifled guns of much larger size firing explosive shells of lighter relative weight (compared to all-metal balls) so greatly increased the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Sight
Iron sights are a system of physical alignment markers used as a sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and bows, or less commonly as a primitive finder sight for optical telescopes. Iron sights, which are typically made of metal, are the earliest and simplest type of sighting device. Since iron sights neither magnify nor illuminate the target, they rely completely on the viewer's naked eye and the available light by which the target is visible. In this respect, iron sights are distinctly different from optical sight designs that employ optical manipulation or active illumination, such as telescopic sights, reflector (reflex) sights, holographic sights, and laser sights. Iron sights are typically composed of two components mounted perpendicularly above the weapon's bore axis: a 'rear sight' nearer (or 'proximal') to the shooter's eye, and a 'front sight' farther forward (or 'distal') near the muzzle. During aim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artillery Battery
In military organizations, an artillery battery is a unit or multiple systems of artillery, mortar systems, rocket artillery, multiple rocket launchers, surface-to-surface missiles, ballistic missiles, cruise missiles, etc., so grouped to facilitate better battlefield communication and command and control, as well as to provide dispersion for its constituent gunnery crews and their systems. The term is also used in a naval context to describe groups of guns on warships. Land usage Historically the term "battery" referred to a cluster of cannons in action as a group, either in a temporary field position during a battle or at the siege of a fortress or a city. Such batteries could be a mixture of cannon, howitzer, or mortar types. A siege could involve many batteries at different sites around the besieged place. The term also came to be used for a group of cannons in a fixed fortification, for coastal or frontier defence. During the 18th century "battery" began to be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
