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Juliet Marine Systems Ghost
Juliet Marine Systems ''Ghost'' is an advanced super-cavitating stealth ship that can reduce hull friction to 1/900th that of conventional watercraft. It was developed to provide superior protection and capabilities for United States military personnel. It was designed, developed, and built by the private American company Juliet Marine Systems. History Inventor Gregory Sancoff had decided to focus on small watercraft following the attack on USS ''Cole'' in 2000, after which he recalled saying: "Some yahoo terrorists in a cheap little boat and $500 worth of explosives can kill 17 sailors on a billion-dollar ship?" He also came across a 630-page United States Navy report on an exercise called Juliet, where the Navy attacked an enemy force of small, high-speed boats; after two days, the Navy had suffered over 20,000 simulated casualties. Sancoff gathered information on marine technology, including hydroplane racing boats and high-speed super-cavitating torpedoes. In 2007, Sanco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercavitation
Supercavitation is the use of a cavitation bubble to reduce skin friction drag on a submerged object and enable high speeds. Applications include torpedoes and propellers, but in theory, the technique could be extended to an entire underwater vessel. Physical principle Cavitation is the formation of vapour bubbles in liquid caused by flow around an object. Bubbles form when water accelerates around sharp corners and the pressure drops below the vapour pressure. Pressure increases upon deceleration, and the water generally reabsorbs the vapour; however, vapour bubbles can implode and apply small concentrated impulses that may damage surfaces like ship propellers and pump impellers. The potential for vapour bubbles to form in a liquid is given by the nondimensional cavitation number. It equals local pressure minus vapour pressure, divided by dynamic pressure. At increasing depths (or pressures in piping), the potential for cavitation is lower because the difference between local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Littoral Combat Ship
The littoral combat ship (LCS) is either of two classes of relatively small surface vessels designed for operations near shore by the United States Navy. It was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating anti-access and asymmetric threats in the littorals." Littoral combat ships are comparable to corvettes found in other navies. The and the are the first two LCS variants. Each is slightly smaller than the U.S. Navy's but larger than ''Cyclone''-class patrol ships. Each has the capabilities of a small assault transport, including a flight deck and hangar for housing two SH-60 or MH-60 Seahawk helicopters, a stern ramp for operating small boats, and the cargo volume and payload to deliver a small assault force with fighting vehicles to a roll-on/roll-off port facility. Standard armaments include Mk 110 57 mm guns and RIM-116 Rolling Airframe Missiles. They are also equipped with autonomous air, surface, and underwater vehicle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonobuoy
A sonobuoy (a portmanteau of sonar and buoy) is a relatively small buoy – typically diameter and long – expendable sonar system that is dropped/ejected from aircraft or ships conducting anti-submarine warfare or underwater acoustic research. Theory of operation Sonobuoys are ejected from aircraft in canisters and deploy upon water impact. An inflatable surface float with a radio transmitter remains on the surface for communication with the aircraft, while one or more hydrophone sensors and stabilizing equipment descend below the surface to a selected depth that is variable, depending on environmental conditions and the search pattern. The buoy relays acoustic information from its hydrophone(s) via UHF/ VHF radio to operators on board the aircraft. History With the technological improvement of the submarine in modern warfare, the need for an effective tracking system was born. Sound Navigation And Ranging (SONAR) was originally developed by the British—who cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Sensor
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discovered tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electro-optical Sensor
Electro-optical sensors are electronic detectors that convert light, or a change in light, into an electronic signal. These sensors are able to detect electromagnetic radiation from the infrared up to the ultraviolet wavelengths. They are used in many industrial and consumer applications, for example: * Lamps that turn on automatically in response to darkness * Position sensors that activate when an object interrupts a light beam * Flash detection, to synchronize one photographic flash to another * Photoelectric sensors that detect the distance, absence, or presence of an object Function An optical sensor converts light rays into electronic signals. It measures the physical quantity of light and then translates it into a form that is readable by an instrument. An optical sensor is generally part of a larger system that integrates a source of light, a measuring device and the optical sensor. This is often connected to an electrical trigger. The trigger reacts to a change in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Precision Kill Weapon System
The AGR-20 Advanced Precision Kill Weapon System (APKWS) is a design conversion of Hydra 70 unguided rockets with a laser guidance kit to turn them into precision-guided munitions (PGMs). APKWS is approximately one-third the cost and one-third the weight of the current inventory of laser-guided weapons, has a lower yield more suitable for avoiding collateral damage, and takes one quarter of the time for ordnance personnel to load and unload. Development Where possible the system utilizes existing Hydra 70 components such as launchers, rocket motors, warheads and fuzes. The weapon bridges the gap between the Hydra 70 and AGM-114 Hellfire systems and provides a cost-effective method of engaging lightly armored point targets. APKWS is the U.S. government's only Program of Record for the semi-active, laser-guided 2.75-inch (70 millimeter) rocket. It converts the Hydra 70 unguided rocket into a precision guided munition through the addition of a mid-body guidance unit develop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AGM-176 Griffin
The AGM-176 Griffin is a lightweight, precision-guided munition developed by Raytheon. It can be launched from the ground or air as a rocket-powered missile or dropped from the air as a guided bomb. It carries a relatively small warhead, and was designed to be a precision low-collateral damage weapon for irregular warfare. It has been used in combat by the United States military during the War in Afghanistan. Development Raytheon developed the Griffin as a low-cost modular system, using components from earlier projects, including the FGM-148 Javelin and the AIM-9X Sidewinder. It was originally designed to be launched from the US Special Operations Command's MC-130W Dragon Spear gunship and can be guided either by a semi-active laser seeker or with GPS. Its precision combined with a relatively small 5.9 kg warhead reduces collateral damage. The munition comes in two versions. Griffin A is an unpowered precision munition that can be dropped from a rear cargo door or a door-mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M197 Electric Cannon
The M197 electric cannon is a 20 mm three-barreled electric Gatling-type rotary cannon used by the United States military. Development The M197 electric cannon was developed primarily for use by United States Army helicopter gunships. Development began in 1967 after experience in the Vietnam War revealed the inadequacy of the 7.62 mm Minigun for gunship use. The M197 is essentially a lightened version of the General Electric M61 Vulcan cannon, with three barrels instead of six. Its maximum rate of fire is one quarter that of the Vulcan, largely to limit its recoil for light aircraft and helicopter use. It shares the Vulcan's M50 and PGU series 20 mm ammunition. History The M197 went into service on later marks of the AH-1 Cobra, using either the M97 or A/A49E-7 armament subsystems, and was also fitted in a ventral turret on the U.S. Marine Corps YOV-10D Bronco NOGS. It is also the basis of the GPU-2/A gun pod, which incorporates the cannon, a battery and ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Mine
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered. Although international law requires signatory nations to declare mined areas, precise locations remain secret; and non-complying individ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-submarine Warfare
Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involved a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines, which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-surface Warfare
Anti-surface warfare (ASuW or ASUW) is the branch of naval warfare concerned with the suppression of surface combatants. More generally, it is any weapons, sensors, or operations intended to attack or limit the effectiveness of an adversary's surface ships. Before the adoption of the submarine and naval aviation, all naval warfare consisted of anti-surface warfare. The distinct concept of an anti-surface warfare capability emerged after World War II, and literature on the subject as a distinct discipline is inherently dominated by the dynamics of the Cold War. Categories of anti-surface warfare Anti-surface warfare can be divided into four categories based on the platform from which weapons are launched: * Air (or aviation): Anti-surface warfare conducted by aircraft. Historically, this was conducted primarily through level- or dive-bombing, strafing runs or air-launching torpedoes (and in some cases by suicide attacks). Today, air ASuW is generally conducted by stand-off att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed F-117 Nighthawk
The Lockheed F-117 Nighthawk is a retired American single-seat, twin-engine stealth attack aircraft developed by Lockheed's secretive Skunk Works division and operated by the United States Air Force (USAF). It was the first operational aircraft to be designed with stealth technology. The F-117 was based on the ''Have Blue'' technology demonstrator. The Nighthawk's maiden flight took place in 1981 at Groom Lake, Nevada, and the aircraft achieved initial operating capability status in 1983. The aircraft was shrouded in secrecy until it was revealed to the public in 1988. Of the 64 F-117s built, 59 were production versions, with the other five being prototypes. The F-117 was widely publicized for its role in the Gulf War of 1991. Although it was commonly referred to as the "Stealth Fighter", it was strictly an attack aircraft. F-117s took part in the conflict in Yugoslavia, where one was shot down by a surface-to-air missile (SAM) in 1999. The U.S. Air Force retired the F-1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
