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Akula-class Submarine
The ''Akula'' class, Soviet designation Project 971 ''Shchuka-B'' (russian: Щука-Б, , Pike-B, NATO reporting name ''Akula'') are a series of fourth generation nuclear-powered attack submarines (SSNs) first deployed by the Soviet Navy in 1986. There are four sub-classes or flights of Shchuka-B, consisting of the original seven Project 971 boats (codenamed ''Akula I''), commissioned between 1984 and 1990; six Project 971Is (Improved ''Akula''s), commissioned between 1991 and 2009; one Project 971U (''Akula II''), commissioned in 1995; and one Project 971M (''Akula III''), commissioned in 2001. The Russians call all of the submarines ''Shchuka-B'', regardless of modifications. Some confusion may exist as the name ''Akula'' (russian: Акула, meaning "shark" in Russian) was used by the Soviets for a different class of submarines, the Project 941, which is known in the West as the . The Project 971 was named ''Shchuka-B'' by the Soviets but given the designation ''Akula'' b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Vepr By Ilya Kurganov Crop
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and Autonomous underwater vehicle, robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as ''boats'' rather than ''ships'' irrespective of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and they were adopted by several navies. They were first widely used during World War I (1914–1918), and are now used in many navy, navies, large and small. Military uses include attacking enemy surface ships (merchant and military) or other submarines, and for aircraft carrier protection, Blockade runner, blockade running, Ballistic missile submarine, nuclear deterrence, reconnaissance, conventio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulsdon
Coulsdon (, traditionally pronounced ) is a town in south London, England, within the London Borough of Croydon, in the ceremonial county of Greater London since 1965. Prior to this it was part of the historic county of Surrey. History The location forms part of the North Downs. The hills contain chalk and flint. A few dry valleys with natural underground drainage merge and connect to the main headwater of the River Wandle, as a winterbourne (stream), so commonly called "the Bourne". Although this breaks onto the level of a few streets when the water table is exceptionally high, the soil is generally dry. The depression and wind gap has been a natural route way across the Downs for early populations. Fossil records exist from the Pleistocene period (about 4,000,000 years ago) There is evidence of human occupation from the Neolithic period, Iron Age,Volume 9 of the Bourne Society's Local History Records (1970) Anglo-Saxon, Bronze Age, Roman and Medieval *675. Frithwald, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Low Frequency
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave as the wavelengths range from one to ten myriameters (an obsolete metric unit equal to 10 kilometers). Due to its limited bandwidth, audio (voice) transmission is highly impractical in this band, and therefore only low data rate coded signals are used. The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves can penetrate at least 40 meters (131 ft) into saltwater, they are used for military communication with submarines. Propagation characteristics Because of their long wavelengths, VLF radio waves can diffract around large obstacles and so are not blocked by mountain ranges, and can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalibr
The 3M-54 Kalibr, (Калибр, caliber), also referred to it as 3M54-1 Kalibr, 3M14 Biryuza (Бирюза, turquoise), (NATO reporting name SS-N-27 Sizzler and SS-N-30A) is a family of Russian cruise missiles developed by the Novator Design Bureau (OKB-8). There are ship-launched, submarine-launched and air-launched versions of the missile, and variants for anti-ship, anti-submarine and land attack use. Some versions have a second propulsion stage that initiates a supersonic sprint in the terminal approach to the target, reducing the time that target's defense systems have to react, while subsonic versions have greater range than the supersonic variants. The missile can carry a warhead weighing up to of explosive or a thermonuclear warhead. Design The missile is a modular system with five versions: two anti-shipping types, one for land attack and two anti-submarine types. The missile is designed to share common parts between the surface and submarine-launched variants but ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RK-55
The Novator RK-55 ''Relief'' (russian: РК-55 Рельеф 'Relief'; NATO: SSC-X-4 'Slingshot'; GRAU: 3K12) is a Russian land-based and submarine-launched cruise missile with a nuclear warhead developed in the Soviet Union. It was about to enter service in 1987, when such weapons were banned under the Intermediate-Range Nuclear Forces Treaty. A version launched from submarine torpedo tubes, the S-10 ''Granat'' (SS-N-21 'Sampson'; GRAU: 3K10), has apparently been converted to carry conventional warheads and continues in service to this day. The Russian Federation was reported to have deployed the derivative SS-CX-7/SS-CX-8 systems on February 14, 2017. The RK-55 is very similar to the air-launched Kh-55 (AS-15 'Kent') but the Kh-55 has a drop-down turbofan engine and was designed by MKB Raduga. Both have formed the basis of post-Cold-War missiles, in particular the 3M-54 Kalibr which has a supersonic approach phase. Development In the late 1960s, the "Ekho" study conducted by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9K38 Igla
The 9K38 Igla (russian: Игла́, "needle", NATO reporting name SA-18 Grouse) is a Russian/Soviet man-portable infrared homing surface-to-air missile (SAM) system. A simplified, earlier version is known as the 9K310 Igla-1 (NATO: SA-16 Gimlet), and the latest variant is the 9K338 Igla-S (SA-24 Grinch). The Igla-1 entered service in 1981, the Igla in 1983, and the Igla-S in 2004. The Igla has been supplemented by the 9K333 Verba since 2014.New Russian Verba MANPADS will replace Igla-S - Armyrecognition.com, 15 September 2014 History The development of the Igla short-range man-portable air defense system ( MA ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identification Friend Or Foe
Identification, friend or foe (IFF) is an identification system designed for command and control. It uses a transponder that listens for an ''interrogation'' signal and then sends a ''response'' that identifies the broadcaster. IFF systems usually use radar frequencies, but other electromagnetic frequencies, radio or infrared, may be used. It enables military and civilian air traffic control interrogation systems to identify aircraft, vehicles or forces as friendly and to determine their bearing and range from the interrogator. IFF is used by both military and civilian aircraft. IFF was first developed during World War II, with the arrival of radar, and several friendly fire incidents. IFF can only positively identify friendly aircraft or other forces. If an IFF interrogation receives no reply or an invalid reply, the object is not positively identified as foe; friendly forces may not properly reply to IFF for various reasons such as equipment malfunction, and parties in the area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decoy
A decoy (derived from the Dutch ''de'' ''kooi'', literally "the cage" or possibly ''ende kooi'', " duck cage") is usually a person, device, or event which resembles what an individual or a group might be looking for, but it is only meant to lure them. Decoys have been used for centuries most notably in game hunting, but also in wartime and in the committing or resolving of crimes. Hunting In hunting wildfowl, the term decoy may refer to two distinct devices. One, the duck decoy (structure), is a long cone-shaped wickerwork tunnel installed on a small pond to catch wild ducks. After the ducks settled on the pond, a small, trained dog would herd the birds into the tunnel. The catch was formerly sent to market for food, but now these are used only by ornithologists to catch ducks to be ringed and released. The word ''decoy'', also originally found in English as "coy", derives from the Dutch ''de Kooi'' (the cage) and dates back to the early 17th century, when this type of duck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Countermeasures
An electronic countermeasure (ECM) is an electrical or electronic device designed to trick or deceive radar, sonar, or other detection systems, like infrared (IR) or lasers. It may be used both offensively and defensively to deny targeting information to an enemy. The system may make many separate targets appear to the enemy, or make the real target appear to disappear or move about randomly. It is used effectively to protect aircraft from guided missiles. Most air forces use ECM to protect their aircraft from attack. It has also been deployed by military ships and recently on some advanced tanks to fool laser/IR guided missiles. It is frequently coupled with stealth advances so that the ECM systems have an easier job. Offensive ECM often takes the form of jamming. Self-protecting (defensive) ECM includes using blip enhancement and jamming of missile terminal homers. History The first example of electronic countermeasures being applied in a combat situation took place during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Warfare Support Measures
In military telecommunications, electronic support (ES) or electronic support measures (ESM) gather intelligence through passive "listening" to electromagnetic radiations of military interest. They are an aspect of electronic warfare involving actions taken under direct control of an operational commander to detect, intercept, identify, locate, record, and/or analyze sources of radiated electromagnetic energy for the purposes of immediate threat recognition (such as warning that fire control RADAR has locked on a combat vehicle, ship, or aircraft) or longer-term operational planning.Polmar, Norman "The U. S. Navy Electronic Warfare (Part 1)" ''United States Naval Institute Proceedings'' October 1979 p.137 Thus, electronic support provides a source of information required for decisions involving electronic protection (EP), electronic attack (EA), avoidance, targeting, and other tactical employment of forces. Electronic support data can be used to produce signals intelligence (SIG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Towed Array Sonar
A towed array sonar is a system of hydrophones towed behind a submarine or a surface ship on a cable. Trailing the hydrophones behind the vessel, on a cable that can be kilometers long, keeps the array's sensors away from the ship's own noise sources, greatly improving its signal-to-noise ratio, and hence the effectiveness of detecting and tracking faint contacts, such as quiet, low noise-emitting submarine threats, or seismic signals. A towed array offers superior resolution and range compared with hull mounted sonar. It also covers the baffles, the blind spot of hull mounted sonar. However, effective use of the system limits a vessel's speed and care must be taken to protect the cable from damage. History During World War I, a towed sonar array known as the "Electric Eel" was developed by Harvey Hayes, a U.S. Navy physicist. This system is believed to be the first towed sonar array design. It employed two cables, each with a dozen hydrophones attached. The project was discontin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
