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Submarine Navigation
Submarine navigation underwater requires special skills and technologies not needed by surface ships. The challenges of underwater navigation have become more important as submarines spend more time underwater, travelling greater distances and at higher speed. Military submarines travel underwater in an environment of total darkness with neither windows nor lights. Operating in stealth mode, they cannot use their active sonar systems to ping ahead for underwater hazards such as undersea mountains, drilling rigs or other submarines. Surfacing to obtain navigational fixes is precluded by pervasive anti-submarine warfare detection systems such as radar and satellite surveillance. Antenna masts and antenna-equipped periscopes can be raised to obtain navigational signals but in areas of heavy surveillance, only for a few seconds or minutes; current radar technology can detect even a slender periscope while submarine shadows may be plainly visible from the air. Navigational techno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Ship
Surface combatants (or surface ships or surface vessels) are a subset of naval warships which are designed for warfare on the surface of the water, with their own weapons and armed forces. They are generally ships built to fight other ships, submarines, aircraft or land targets, and can carry out several other missions including counter-narcotics operations and maritime interdiction. Their primary purpose is to engage space, air, surface, and submerged targets with weapons deployed from the ship itself, rather than by manned carried craft.Naval Transformational Roadmap . Retrieved 2009-08-29. Surface ships include |
Global Positioning System
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite systems (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. It does not require the user to transmit any data, and operates independently of any telephonic or Internet reception, though these technologies can enhance the usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls and maintains the GPS system, it is freely accessible to anyone with a GPS receiver. The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft was lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voyage Management System
Voyage(s) or The Voyage may refer to: Literature *''Voyage : A Novel of 1896'', Sterling Hayden * ''Voyage'' (novel), a 1996 science fiction novel by Stephen Baxter *''The Voyage'', Murray Bail * "The Voyage" (short story), a 1921 story by Katherine Mansfield * "Voyage", a poem by Patti Smith from her 1996 book '' The Coral Sea'' * ''Voyages'' (poem), a 1926 poem by Hart Crane *Le Voyage, 1996 graphic novel, see Edmond Baudoin *Le Voyage, poem by Baudelaire Film and television * ''The Voyage'' (1921 film), an Italian silent drama film * ''The Voyage'' (1974 film), an Italian film * ''Voyage'' (2013 film), a Hong Kong film made mostly in English * ''Voyages'' (film), a 1999 film directed by Emmanuel Finkiel * ''Voyage'' (1993 film), a 1993 American TV film directed by John Mackenzie * Voyage.tv, an American online travel channel * Voyages Television, an international travel marketing channel * Voyage (French TV channel), a television channel in France operated by Path ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Waters
According to the United Nations Convention on the Law of the Sea, a nation's internal waters include waters on the side of the baseline of a nation's territorial waters that is facing toward the land, except in archipelagic states. It includes waterways such as rivers and canals, and sometimes the water within small bays. In inland waters, sovereignty of the state is equal to that which it exercises on the mainland. The coastal state is free to make laws relating to its internal waters, regulate any use, and use any resource. In the absence of agreements to the contrary, foreign vessels have no right of passage within internal waters, and this lack of right to innocent passage is the key difference between internal waters and territorial waters.UN Convention on the Law of the Sea, Part II, Article 2 The "archipelagic waters" within the outermost islands of archipelagic states are treated as internal waters with the exception that innocent passage must be allowed, although the arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilotage
Piloting or pilotage is the process of navigating on water or in the air using fixed points of reference on the sea or on land, usually with reference to a nautical chart or aeronautical chart to obtain a fix of the position of the vessel or aircraft with respect to a desired course or location. Horizontal fixes of position from known reference points may be obtained by sight or by radar. Vertical position may be obtained by depth sounder to determine depth of the water body below a vessel or by altimeter to determine an aircraft's altitude, from which its distance above the ground can be deduced. Piloting a vessel is usually practiced close to shore or on inland waterways. Pilotage of an aircraft is practiced under visual meteorological conditions for flight. Land navigation is a related discipline, using a topographic map, especially when applied over trackless terrain. Divers use related techniques for underwater navigation. Piloting references Charts Depending on wheth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic) to extrem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Navigation
Radar navigation is the utilization of marine and aviation radar systems for vessel and aircraft navigation. When a craft is within radar range of land or special radar aids to navigation, the navigator can take distances and angular bearings to charted objects and use these to establish arcs of position and lines of position on a chart.Maloney, 2003:744. A fix consisting of only radar information is called a ''radar fix''.Bowditch, 2002:816. Some types of radar fixes include the relatively self-explanatory methods of "range and bearing to a single object,"National Imagery and Mapping Agency, 2001:163. "two or more bearings," "tangent bearings," and "two or more ranges." Parallel indexing is a technique defined by William Burger in the 1957 book ''The Radar Observer's Handbook''.National Imagery and Mapping Agency, 2001:169. This technique involves creating a line on the screen that is parallel to the ship's course, but offset to the left or right by some distance. This p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Navigation
Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space (or on the surface of the Earth) without having to rely solely on estimated positional calculations, commonly known as "dead reckoning", made in the absence of satellite navigation or other similar modern electronic or digital positioning means. Celestial navigation uses "sights", or timed angular measurements, taken typically between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. Celestial navigation can also take advantage of measurements between celestial bodies without reference to the Earth horizon, such as when the Moon and other selected bodies are used in the practice called "lunars" or lunar distance method, used for determining precise time when time is unknown. Celestial navigation by taking sights of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha (navigation)
Alpha, also known as RSDN-20, is a Russian system for long range radio navigation. RSDN in Russian stands for (''radiotehnicheskaya Sistema Dal'ney Navigatsii''), which translates to English as "radio-technical long-distance navigation system". Alpha was used to determine positions of aircraft, ships, and submarines (in underwater positions). The system was developed in parallel with U.S. Omega navigational system, and also works in VLF-range. Alpha coverage is up to 10,000 km from the master station, with a position error of . The Alpha system consists of three transmitters, placed in the proximity of Novosibirsk, Krasnodar and Khabarovsk. Two other transmitters at Revda and Seyda are not currently operational . These transmitters radiate signals of 0.4 second duration, in a 3.6 second cycle, on the frequencies F1: 11.904761 kHz, F2: 12.648809 kHz and F3: 14.880952 kHz. A radio fix is taken by measuring the phase difference of the received signals. Other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omega (navigation System)
OMEGA was the first global-range radio navigation system, operated by the United States in cooperation with six partner nations. It was a hyperbolic navigation system, enabling ships and aircraft to determine their position by receiving very low frequency (VLF) radio signals in the range 10 to 14 kHz, transmitted by a global network of eight fixed terrestrial radio beacons, using a navigation receiver unit. It became operational around 1971 and was shut down in 1997 in favour of the Global Positioning System. History Previous systems Taking a " fix" in any navigation system requires the determination of two measurements. Typically these are taken in relation to fixed objects like prominent landmarks or the known location of radio transmission towers. By measuring the angle to two such locations, the position of the navigator can be determined. Alternately, one can measure the angle and distance to a single object, or the distance to two objects. The introduction of radio s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHAYKA
Chayka (russian: Чайка, lit. "seagull") also known as Radioteknicheskaya Systema Dalyoloiy Navigatsii abbreviated as RSDN (lit. Russian Hyperbolic Radio Navigation System) is a Russian terrestrial radio navigation system, similar to Loran-C. It operates on similar frequencies around 100 kHz, and uses the same techniques of comparing both the envelope and the signal phase to accurately determine location. The systems differ primarily in details. Chayka-Chains Chayka, like LORAN-C, uses different pulse repetition frequencies (Group Repetition Intervals, or GRIs) to allow the identification of different stations operating on the same frequencies. There are 5 Chayka chains in use: *GRI 8000 — Western (European) Russia Chayka Chain (1969, RSDN-3/10) *GRI 7950 — Eastern Russia Chayka Chain (1986, RSDN-4) *GRI 5980 — Russian-American Chayka Chain (1995) *GRI 5960 — Northern Chayka Chain (1996, RSDN-5) *GRI 4970 — North-Western Chayka Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbolic Navigation
Hyperbolic navigation is a class of radio navigation systems in which a navigation receiver instrument is used to determine location based on the difference in timing (phase) of radio waves received from radio navigation beacon transmitters. Such systems rely on the ability of two widely separated stations to broadcast a signal that is highly correlated in time. Typical systems either broadcast short pulses at the same time, or continual signals that are identical in phase. A receiver located at the midpoint between the two stations will receive the signals at the same time or have identical phase, but at any other location the signal from the closer station will be received first or have a different phase. Determining the location of a receiver requires that the two synchronized stations be tuned in at the same time so the signals can be compared. This reveals a ''difference'' in time, corresponding to a relative distance closer to one station or the other. Plotting all the loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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