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Extended Range Guided Munition
The Extended Range Guided Munition was a precision guided rocket-assisted 5-inch (127 mm) shell (projectile) development by Raytheon for the U.S. Navy. The program was cancelled in March 2008 after twelve years of development and over 600 million dollars in funding. The developmental round was designated EX 171. ERGM consisted of three major subsections: propulsion (rocket motor), warhead, and Guidance, Navigation and Control section. ERGM is fired from the 127 mm (5 inch) 62 Caliber Mark 45 gun Mod 4, at which point the would fins deploy and the rocket motor would ignite, lifting the munition to at least 80,000 feet (24 km), after which the canards would deploy and guide the ERGM to the target using GPS guidance. It was to be used on ''Arleigh Burke''-class destroyers (hulls DDG-51 through 112). Despite the long development time, the ERGM never worked as reliably as the older but significantly less expensive laser-guided M712 Copperhead. During development, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exponential Random Graph Model
Exponential family random graph models (ERGMs) are a family of statistical models for analyzing data from social and other networks. Examples of networks examined using ERGM include knowledge networks, organizational networks, colleague networks, social media networks, networks of scientific development, and others. Background Many metrics exist to describe the structural features of an observed network such as the density, centrality, or assortativity. However, these metrics describe the observed network which is only one instance of a large number of possible alternative networks. This set of alternative networks may have similar or dissimilar structural features. To support statistical inference on the processes influencing the formation of network structure, a statistical model should consider the set of all possible alternative networks weighted on their similarity to an observed network. However because network data is inherently relational, it violates the assumptions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circular Error Probable
In the military science of ballistics, circular error probable (CEP) (also circular error probability or circle of equal probability) is a measure of a weapon system's precision. It is defined as the radius of a circle, centered on the mean, whose perimeter is expected to include the landing points of 50% of the rounds; said otherwise, it is the median error radius. That is, if a given munitions design has a CEP of 100 m, when 100 munitions are targeted at the same point, 50 will fall within a circle with a radius of 100 m around their average impact point. (The distance between the target point and the average impact point is referred to as bias.) There are associated concepts, such as the DRMS (distance root mean square), which is the square root of the average squared distance error, and R95, which is the radius of the circle where 95% of the values would fall in. The concept of CEP also plays a role when measuring the accuracy of a position obtained by a navig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Assisted Projectile
A rocket-assisted projectile (RAP) is a cannon, howitzer, mortar, or recoilless rifle round incorporating a rocket motor for independent propulsion. This gives the projectile greater speed and range than a non-assisted ballistic shell, which is propelled only by the gun's exploding charge. Some forms of rocket-assisted projectiles can be outfitted with a laser-guide for greater accuracy. The German Sturmtiger (1944) used a 380 mm Rocket Propelled Round as its main projectile. These rounds were high explosive shells or shaped charges with a maximum range of 6,000 m. The gun first accelerated the projectile to 45 m/s (150 ft/s), the 40 kg (88 lb) rocket charge then boosted this to about 250 m/s (820 ft/s). Also the German Krupp K5 railway gun of World War 2 used rocket assisted projectiles in the later stages of the war, although it also used conventional artillery projectiles. The North Korean M-1978 / M1989 (KOKSAN) 170mm self-propelled gun can use rocket assisted proje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Range Land Attack Projectile
The Long Range Land Attack Projectile (LRLAP) is a cancelled precision guided 155 mm naval artillery shell for the U.S. Navy's Advanced Gun System (AGS). LRLAP was developed and produced by Lockheed Martin Missiles and Fire Control, the prime contractor being BAE Systems. The LRLAP would have used a rocket-assisted projectile with fin glide trajectory. The warhead effectiveness was considered comparable to that of the M795 artillery shell, and with the AGS it would have been capable of 6 round Multiple Rounds Simultaneous Impact (MRSI) in a span of 2 seconds. It would have used a blast fragmentation type warhead. The LRLAP was designed for use in the AGS and is not compatible with any other weapon. The AGS is used only on the ''Zumwalt''-class destroyer, with two AGSs on each ship. In November 2016, the Navy announced it had decided to cancel procurement of the LRLAP. This was due to rising costs resulting from the trimming of the ''Zumwalt''-class destroyer fleet to jus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Trajectory Extended Range Munition
The Ballistic Trajectory Extended Range Munition (BTERM) was a failed program to develop a precision guided rocket-assisted 127 mm (5-inch) artillery shell for the U.S. Navy. The program was originally named the Autonomous Naval Support Round (ANSR) and was developed by Alliant Techsystems. The concept was similar to Raytheon's Extended Range Guided Munition with several simplifications and a larger rocket engine. The warhead was based upon that in the AGM-88 HARM anti-radiation missile, and was guided through GPS; however, unlike the ERGM it was intended to fly a strictly ballistic trajectory. Both programs were cancelled in 2008. Specification * Caliber: 127 mm (5 in) * Guidance: GPS/ INS * Propulsion: Solid-propellant rocket engine * Warhead: Blast- fragmentation See also * Long Range Land Attack Projectile * M712 Copperhead * M982 Excalibur The M982 Excalibur (previously XM982) is a 155 mm extended-range guided artillery shell developed in a collaborative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Sands Missile Range
White Sands Missile Range (WSMR) is a United States Army military testing area and firing range located in the US state of New Mexico. The range was originally established as the White Sands Proving Ground on 9July 1945. White Sands National Park is located within the range. Significant events *The first atomic bomb (code named Trinity) was test detonated at Trinity Site near the northern boundary of the range on 16 July 1945, seven days after the White Sands Proving Ground was established. *After the conclusion of World War II, 100 long-range German V-2 rockets that were captured by U.S. military troops were brought to WSMR. Of these, 67 were test-fired between 1946 and 1951 from the White Sands V-2 Launching Site. (This was followed by the testing of American rockets, which continues to this day, along with testing other technologies.) *NASA's Space Shuttle Columbia landed on the Northrop Strip at WSMR on 30 March 1982 as the conclusion to mission STS-3. This was the only t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Flight
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. Data is sampled during the flight of an aircraft, or atmospheric testing of launch vehicles and reusable spacecraft. This data is validated for accuracy and analyzed before being passed to specialist engineering groups for further analysis to validate the design of the vehicle. The flight test phase accomplishes two major tasks: 1) finding and fixing any design problems and then 2) verifying and documenting the vehicle capabilities for government certification or customer acceptance. The flight test phase can range from the test of a single new system for an existing vehicle to the complete development and certification of a new aircraft, launch vehicle, or reusable spacecraft. Therefore, the duration of a particular flight test program ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or BLEVE * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Explosives may als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submunition
A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy vehicles. Other cluster munitions are designed to destroy runways or electric power transmission lines, disperse chemical or biological weapons, or to scatter land mines. Some submunition-based weapons can disperse non-munitions, such as leaflets. Because cluster bombs release many small bomblets over a wide area, they pose risks to civilians both during attacks and afterwards. Unexploded bomblets can kill or maim civilians and/or unintended targets long after a conflict has ended, and are costly to locate and remove. Cluster munitions are prohibited for those nations that ratified the Convention on Cluster Munitions, adopted in Dublin, Ireland, in May 2008. The Convention entered into force and became binding international law upon ratifying ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Motor
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance with Newton's third law. Most rocket engines use the combustion of reactive chemicals to supply the necessary energy, but non-combusting forms such as cold gas thrusters and nuclear thermal rockets also exist. Vehicles propelled by rocket engines are commonly called rockets. Rocket vehicles carry their own oxidiser, unlike most combustion engines, so rocket engines can be used in a vacuum to propel spacecraft and ballistic missiles. Compared to other types of jet engine, rocket engines are the lightest and have the highest thrust, but are the least propellant-efficient (they have the lowest specific impulse). The ideal exhaust is hydrogen, the lightest of all elements, but chemical rockets produce a mix of heavier species, reducing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which is contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
