Array ( [0] => {{short description|Process of monitoring and controlling the movement of a craft or vehicle from one place to another}} [1] => {{other uses}} [2] => [[File:Navigation system on a merchant ship.jpg|thumb|A navigation system on an [[oil tanker]]]] [3] => '''Navigation''' is a field of study that focuses on the process of monitoring and controlling the [[motion|movement]] of a craft or [[vehicle]] from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation,The Handbook Of The SAS And Elite Forces. How The Professionals Fight And Win. Edited by Jon E. Lewis. p.363-Tactics And Techniques, Personal Skills And Techniques. Robinson Publishing Ltd 1997. ISBN 1-85487-675-9 [[marine navigation]], aeronautic navigation, and space navigation.{{cite book|last=Rell Pros-Wellenhof|first=Bernhard|title=Navigation: Principles of Positioning and Guidances|year=2007|publisher=Springer|isbn=978-3-211-00828-7|pages=5–6}} [4] => [5] => It is also the term of art used for the specialized knowledge used by [[navigator]]s to perform navigation tasks. All navigational techniques involve locating the navigator's [[Position (geometry)|position]] compared to known locations or patterns. [6] => [7] => Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and [[Relative direction|direction]]. In this sense, navigation includes [[orienteering]] and [[pedestrian]] navigation. [8] => [9] => ==History== [10] => {{Further|History of navigation}} [11] => {{see also|History of geodesy}} [12] => In the European medieval period, navigation was considered part of the set of ''[[Artes mechanicae|seven mechanical arts]]'', none of which were used for long voyages across open ocean. [[Polynesian navigation]] is probably the earliest form of open-ocean navigation; it was based on memory and observation recorded on scientific instruments like the [[Marshall Islands stick chart|Marshall Islands Stick Charts of Ocean Swells]]. Early Pacific Polynesians used the motion of stars, weather, the position of certain wildlife species, or the size of waves to find the path from one island to another. [13] => [14] => Maritime navigation using scientific instruments such as the [[mariner's astrolabe]] first occurred in the Mediterranean during the Middle Ages. Although [[astrolabe|land astrolabes]] were invented in the [[Hellenistic period]] and existed in [[classical antiquity]] and the [[Islamic Golden Age]], the oldest record of a sea astrolabe is that of [[Spanish people|Spanish]] astronomer [[Ramon Llull]] dating from 1295.''The Ty Pros Companion to Ships and the Sea'', Peter Kemp ed., 1976 {{ISBN|0-586-08308-1}} The perfecting of this navigation instrument is attributed to [[Portuguese Empire|Portuguese]] navigators during early [[Portuguese discoveries]] in the [[Age of Discovery]].{{cite book |author=Comandante Estácio dos Reis |title=Astrolábios Náuticos |year=2002 |publisher=INAPA |isbn=978-972-797-037-7}}{{cite web |url=http://www.ancruzeiros.pt/anci-astrolabio.html |title=Archived copy |access-date=2013-04-02 |url-status=dead |archive-url=https://web.archive.org/web/20121122134304/http://www.ancruzeiros.pt/anci-astrolabio.html |archive-date=2012-11-22 }} The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer [[Martín Cortés de Albacar]]'s ''Arte de Navegar'' (''The Art of Navigation'') published in 1551,Swanick, Lois Ann. ''An Analysis Of Navigational Instruments In The Age Of Exploration: 15th Century To Mid-17th century'', MA Thesis, Texas A&M University, December 2005 based on the principle of the [[archipendulum]] used in constructing the [[Egyptian pyramids]]. [15] => [16] => Open-seas navigation using the astrolabe and the [[compass]] started during the Age of Discovery in the 15th century. The Portuguese began systematically exploring the [[Atlantic]] coast of [[Africa]] from 1418, under the sponsorship of [[Henry the Navigator|Prince Henry]]. In 1488 [[Bartolomeu Dias]] reached the [[Indian Ocean]] by this route. In 1492 the [[Ferdinand and Isabella|Spanish monarchs]] funded [[Christopher Columbus]]'s expedition to sail west to reach the [[Indies]] by crossing the Atlantic, which resulted in the [[Discovery of the Americas]]. In 1498, a Portuguese expedition commanded by [[Vasco da Gama]] reached [[India]] by sailing around Africa, opening up direct trade with [[Asia]]. Soon, the Portuguese sailed further eastward, to the [[Maluku Islands|Spice Islands]] in 1512, landing in [[China]] one year later. [17] => [18] => The first circumnavigation of the earth was completed in 1522 with the [[Timeline of Magellan's circumnavigation|Magellan-Elcano expedition]], a Spanish voyage of discovery led by Portuguese explorer [[Ferdinand Magellan]] and completed by Spanish navigator [[Juan Sebastián Elcano]] after the former's death in the [[Philippines]] in 1521. The fleet of seven ships sailed from [[Sanlúcar de Barrameda]] in Southern [[Spain]] in 1519, crossed the Atlantic Ocean and after several stopovers rounded the southern tip of [[South America]]. Some ships were lost, but the remaining fleet continued across the [[Pacific]] making a number of discoveries including [[Guam]] and the Philippines. By then, only two galleons were left from the original seven. The ''Victoria'' led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to finally arrive in Spain in 1522, three years after its departure. The ''Trinidad'' sailed east from the Philippines, trying to find a maritime path back to the [[Americas]], but was unsuccessful. The eastward route across the Pacific, also known as the ''tornaviaje'' (return trip) was only discovered forty years later, when Spanish cosmographer [[Andrés de Urdaneta]] sailed from the Philippines, north to parallel 39°, and hit the eastward [[Kuroshio Current]] which took its galleon across the Pacific. He arrived in [[Acapulco]] on October 8, 1565. [19] => [20] => ==Etymology== [21] => The term stems from the 1530s, from [[Latin]] ''navigationem'' (nom. ''navigatio''), from ''navigatus'', pp. of ''navigare'' "to sail, sail over, go by sea, steer a ship," from ''navis'' "ship" and the root of ''agere'' "to drive".{{Cite web |title=Etymonline - Online Etymology Dictionary |url=https://www.etymonline.com/search?q=navigation&ref=searchbar_searchhint |website=www.etymonline.com}} [22] => {{clear}} [23] => [24] => ==Basic concepts== [25] => {{longlat}} [26] => [27] => ===Latitude=== [28] => {{Further|Latitude}} [29] => Roughly, the latitude of a place on Earth is its angular distance north or south of the [[equator]].Bowditch, 2003:4. Latitude is usually expressed in [[degree (angle)|degrees]] (marked with °) ranging from 0° at the [[Equator]] to 90° at the North and South poles. The latitude of the [[North Pole]] is 90° N, and the latitude of the [[South Pole]] is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the [[pole star]] ([[Polaris]]) with a [[sextant]] and using sight reduction tables to correct for height of eye and atmospheric refraction. The height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so. [30] => [31] => ===Longitude=== [32] => {{Further|Longitude}} [33] => Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the [[prime meridian]] or [[Greenwich meridian]]. Longitude is usually expressed in [[degree (angle)|degrees]] (marked with °) ranging from [[prime meridian|0°]] at the Greenwich meridian to [[180th meridian|180°]] east and west. [[Sydney]], for example, has a longitude of about [[151st meridian east|151° east]]. [[New York City]] has a longitude of [[74th meridian west|74° west]]. For most of history, mariners struggled to determine longitude. Longitude can be calculated if the precise time of a sighting is known. Lacking that, one can use a [[sextant]] to take a [[Lunar distance (navigation)|lunar distance]] (also called ''the lunar observation'', or "lunar" for short) that, with a [[nautical almanac]], can be used to calculate the time at zero longitude (see [[Greenwich Mean Time]]). [34] => {{cite book [35] => | last =Norie [36] => | first =J.W. [37] => | title =New and Complete Epitome of Practical Navigation [38] => | year =1828 [39] => | location =London [40] => | url =http://www.mysticseaport.org/library/initiative/ImPage.cfm?PageNum=3&BibId=13617&ChapterId=30 [41] => | access-date =2007-08-02 [42] => | page =222 [43] => | url-status=dead [44] => | archive-url =https://web.archive.org/web/20070927203111/http://www.mysticseaport.org/library/initiative/ImPage.cfm?PageNum=3&BibId=13617&ChapterId=30 [45] => | archive-date =2007-09-27 [46] => }} Reliable [[marine chronometer]]s were unavailable until the late 18th century and not affordable until the 19th century. [47] => {{cite book [48] => | last =Norie [49] => | first =J.W. [50] => | title =New and Complete Epitome of Practical Navigation [51] => | year =1828 [52] => | location =London [53] => | url =http://www.mysticseaport.org/library/initiative/ImPage.cfm?PageNum=2&BibId=13617&ChapterId=30 [54] => | access-date =2007-08-02 [55] => | page =221 [56] => | url-status=dead [57] => | archive-url =https://web.archive.org/web/20070927202912/http://www.mysticseaport.org/library/initiative/ImPage.cfm?PageNum=2&BibId=13617&ChapterId=30 [58] => | archive-date =2007-09-27 [59] => }}{{Cite book [60] => | last = Taylor [61] => | first = Janet [62] => | title=An Epitome of Navigation and Nautical Astronomy [63] => | publisher = Taylor [64] => | edition = Ninth [65] => | year = 1851 [66] => | url=https://archive.org/details/anepitomenaviga00taylgoog [67] => | quote = Nautical Almanac 1849-1851. [68] => | access-date=2007-08-02 [69] => | page = 295f [70] => }} [71] => [72] => {{cite book [73] => | first=Frederick James [74] => | last=Britten [75] => | title = Former Clock & Watchmakers and Their Work [76] => | year = 1894 [77] => | publisher=Spon & Chamberlain [78] => | location = New York [79] => |url=https://archive.org/details/formerclockwatc00britgoog [80] => | quote=Chronometers were not regularly supplied to the Royal Navy until about 1825 [81] => |access-date=2007-08-08 [82] => | page=[https://archive.org/details/formerclockwatc00britgoog/page/n242 230] [83] => }} For about a hundred years, from about 1767 until about 1850,Lecky, Squire, ''Wrinkles in Practical Navigation'' mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich time.{{cite book [84] => |last= Roberts |first= Edmund |author-link= Edmund Roberts (diplomat) [85] => |title= Embassy to the Eastern courts of Cochin-China, Siam, and Muscat: in the U.S. sloop-of-war Peacock ... during the years 1832–3–4 [86] => |url= https://books.google.com/books?id=aSgPAAAAYAAJ [87] => |date= 1837 |publisher= Harper & brothers [88] => |page= 373 |no-pp= [89] => |chapter= Chapter XXIV―departure from Mozambique [90] => |isbn= 9780608404066 |chapter-url= https://books.google.com/books?id=aSgPAAAAYAAJ&pg=PA365 [91] => |access-date= April 25, 2012 [92] => |edition= Digital [93] => |quote= ...what I have stated, will serve to show the absolute necessity of having firstrate chronometers, or the lunar observations carefully attended to; and never omitted to be taken when practicable. [94] => }} [95] => [96] => ===Loxodrome=== [97] => {{Further|Rhumb line}} [98] => In navigation, a rhumb line (or loxodrome) is a line crossing all meridians of longitude at the same angle, i.e. a path derived from a defined initial bearing. That is, upon taking an initial bearing, one proceeds along the same bearing, without changing the direction as measured relative to true or magnetic north. [99] => [100] => ==Methods of navigation== [101] => Most [[Navigation system|modern navigation]] relies primarily on positions determined electronically by receivers collecting information from satellites. Most other modern techniques rely on finding intersecting [[line of position|lines of position]] or LOP.Maloney, 2003:615. [102] => [103] => A line of position can refer to two different things, either a line on a chart or a line between the observer and an object in real life.Maloney, 2003:614 A bearing is a measure of the direction to an object. If the navigator measures the direction in real life, the angle can then be drawn on a [[nautical chart]] and the navigator will be somewhere on that bearing line on the chart. [104] => [105] => In addition to bearings, navigators also often measure distances to objects. On the chart, a distance produces a circle or arc of position. Circles, arcs, and hyperbolae of positions are often referred to as lines of position. [106] => [107] => If the navigator draws two lines of position, and they intersect he must be at that position. A [[fix (position)|fix]] is the intersection of two or more LOPs. [108] => [109] => If only one line of position is available, this may be evaluated against the [[dead reckoning]] position to establish an estimated position.Maloney, 2003:618. [110] => [111] => Lines (or circles) of position can be derived from a variety of sources: [112] => * celestial observation (a short segment of the [[circle of equal altitude]], but generally represented as a line), [113] => * terrestrial range (natural or man made) when two charted points are observed to be in line with each other,Maloney, 2003:622. [114] => * compass bearing to a charted object, [115] => * radar range to a charted object, [116] => * on certain coastlines, a depth sounding from [[Fathometer|echo sounder]] or hand [[Sounding line|lead line]]. [117] => [118] => There are some methods seldom used today such as "dipping a light" to calculate the geographic range from observer to lighthouse. [119] => [120] => Methods of navigation have changed through history.Bowditch, 2002:1. Each new method has enhanced the mariner's ability to complete his voyage. One of the most important judgments the navigator must make is the best method to use. Some types of navigation are depicted in the table. [121] => [122] => {| class="wikitable" style="font-size:95%" [123] => |- [124] => ! Illustration !! Description !! Application [125] => |- valign="top" [126] => ! colspan="3" | Traditional navigation methods include: [127] => |- valign="top" [128] => |[[File:Cruising sailor navigating.jpg|100px]] [129] => |In marine navigation, [[dead reckoning]] or DR, in which one advances a prior position using the ship's course and speed. The new position is called a DR position. It is generally accepted that only course and speed determine the DR position. Correcting the DR position for [[leeway]], current effects, and steering error result in an estimated position or EP. An [[Inertial guidance system|inertial navigator]] develops an extremely accurate EP. [130] => |Used at all times. [131] => |-valign="top" [132] => |[[File:SplitPointLighthouse.jpg|100px]] [133] => |In marine navigation, [[pilotage]] involves navigating in restricted/coastal waters with frequent determination of position relative to geographic and hydrographic features. [134] => |When within sight of land. [135] => |-valign="top" [136] => |[[File:Orienteering map.jpg|100px]] [137] => |[[Land navigation]] is the discipline of following a route through terrain on foot or by vehicle, using maps with reference to terrain, a compass, and other basic navigational tools and/or using landmarks and signs. [[Wayfinding]] is the more basic form. [138] => |Used at all times. [139] => |-valign="top" [140] => |[[File:Moon-Mdf-2005.jpg|100px]] [141] => |[[Celestial navigation]] involves reducing celestial measurements to lines of position using tables, [[spherical trigonometry]], and [[Nautical almanac|almanacs]]. It is primarily used at sea but can also be used on land. [142] => |Used primarily as a backup to [[satellite navigation|satellite]] and other [[Radio navigation|electronic systems]] in the open ocean. [143] => |-valign="top" [144] => ! colspan="3" | [[Electronic navigation]] covers any method of [[position fixing]] using electronic means, including: [145] => |-valign="top" [146] => |[[File:Decca Navigator Mk 12.jpg|100px]] [147] => |[[Radio navigation]] uses radio waves to determine position by either [[radio direction finder|radio direction finding systems]] or hyperbolic systems, such as [[Decca Navigator System|Decca]], [[OMEGA Navigation System|Omega]] and [[LORAN-C]]. [148] => | Availability has declined due to the development of accurate GNSS. [149] => |-valign="top" [150] => |[[File:Radar screen.JPG|100px]] [151] => |[[Radar navigation]] uses radar to determine the distance from or bearing of objects whose position is known. This process is separate from radar's use as a collision avoidance system. [152] => | Primarily when within radar range of land. [153] => |-valign="top" [154] => |[[File:GPS Satellite NASA art-iif.jpg|100px]] [155] => |[[Satellite navigation]] uses a Global Navigation Satellite System (GNSS) to determine position. [156] => |Used in all situations. [157] => |} [158] => [159] => The practice of navigation usually involves a combination of these different methods. [160] => [161] => ===Mental navigation checks=== [162] => By mental navigation checks, a pilot or a navigator estimates tracks, distances, and altitudes which will then help the pilot avoid gross navigation errors.''The Handbook of the SAS and Elite Forces. How the Professionals Fight and Win''. Edited by Jon E. Lewis. p. 370 "Tactics And Techniques, Personal Skills And Techniques". Robinson Publishing Ltd 1997. {{ISBN|1854876759}} [163] => [164] => ===Piloting=== [165] => {{Further|Pilotage}} [166] => [[File:Navigatie.jpg|thumb|Manual navigation through Dutch airspace]] [167] => Piloting (also called pilotage) involves navigating an aircraft by visual reference to landmarks,Federal Aviation Regulations Part 1 §1.1 or a water vessel in restricted waters and fixing its position as precisely as possible at frequent intervals.Bowditch, 2002:105. More so than in other phases of navigation, proper preparation and attention to detail are important. Procedures vary from vessel to vessel, and between military, commercial, and private vessels. As pilotage takes place in [[Waves and shallow water|shallow waters]], it typically involves following courses to ensure sufficient [[under keel clearance]], ensuring a sufficient depth of water below the [[Draft (hull)|hull]] as well as a consideration for [[Squat effect|squat]].{{cite book | last=Gilardoni | first=Eduardo O. | last2=Presedo | first2=Juan P. | title=Navigation in Shallow Waters | publisher=Witherbys | publication-place=Livingston, Scotland | date=2017 | isbn=978-1-85609-667-6}} It may also involve navigating a ship within a river, [[canal]] or [[Channel (geography)|channel]] in close proximity to land. [168] => [169] => A military navigation team will nearly always consist of several people. A military navigator might have bearing takers stationed at the gyro repeaters on the bridge wings for taking simultaneous bearings, while the civilian navigator on a merchant ship or leisure craft must often take and plot their position themselves, typically with the aid of electronic position fixing. While the military navigator will have a bearing book and someone to record entries for each fix, the civilian navigator will simply pilot the bearings on the chart as they are taken and not record them at all. If the ship is equipped with an [[ECDIS]], it is reasonable for the navigator to simply monitor the progress of the ship along the chosen track, visually ensuring that the ship is proceeding as desired, checking the compass, sounder and other indicators only occasionally. If a [[harbour pilot|pilot]] is aboard, as is often the case in the most restricted of waters, his judgement can generally be relied upon, further easing the workload. But should the ECDIS fail, the navigator will have to rely on his skill in the manual and time-tested procedures. [170] => [171] => ===Celestial navigation=== [172] => {{Main|Celestial navigation}} [173] => [[File:Sun-Moon path.PNG|thumb|upright=1.2|A celestial fix will be at the intersection of two or more circles.]] [174] => [175] => Celestial navigation systems are based on observation of the positions of the [[Sun]], [[Moon]], [[planet]]s and [[list of selected stars for navigation|navigational stars]]. Such systems are in use as well for terrestrial navigating as for interstellar navigating. By knowing which point on the rotating Earth a celestial object is above and measuring its height above the observer's horizon, the navigator can determine his distance from that subpoint. A [[nautical almanac]] and a [[marine chronometer]] are used to compute the subpoint on Earth a celestial body is over, and a [[sextant]] is used to measure the body's angular height above the horizon. That height can then be used to compute distance from the subpoint to create a circular line of position. A navigator shoots a number of stars in succession to give a series of overlapping lines of position. Where they intersect is the celestial fix. The Moon and Sun may also be used. The Sun can also be used by itself to shoot a succession of lines of position (best done around local noon) to determine a position. [176] => [177] => ====Marine chronometer==== [178] => {{main|Marine chronometer}} [179] => In order to accurately measure longitude, the precise time of a sextant sighting (down to the second, if possible) must be recorded. Each second of error is equivalent to 15 seconds of longitude error, which at the equator is a position error of .25 of a nautical mile, about the accuracy limit of manual celestial navigation. [180] => [181] => The spring-driven marine chronometer is a precision timepiece used aboard ship to provide accurate time for celestial observations.Bowditch, 2002:269. A chronometer differs from a spring-driven watch principally in that it contains a variable lever device to maintain even pressure on the mainspring, and a special balance designed to compensate for temperature variations. [182] => [183] => A spring-driven chronometer is set approximately to Greenwich mean time (GMT) and is not reset until the instrument is overhauled and cleaned, usually at three-year intervals. The difference between GMT and chronometer time is carefully determined and applied as a correction to all chronometer readings. Spring-driven chronometers must be wound at about the same time each day. [184] => [185] => [[Quartz clock#Accuracy enhancement|Quartz crystal marine chronometers]] have replaced spring-driven chronometers aboard many ships because of their greater accuracy. They are maintained on GMT directly from radio time signals. This eliminates chronometer error and watch error corrections. Should the second hand be in error by a readable amount, it can be reset electrically. [186] => [187] => The basic element for time generation is a quartz crystal oscillator. The quartz crystal is temperature compensated and is hermetically sealed in an evacuated envelope. A calibrated adjustment capability is provided to adjust for the aging of the crystal. [188] => [189] => The chronometer is designed to operate for a minimum of one year on a single set of batteries. Observations may be timed and ship's clocks set with a comparing watch, which is set to chronometer time and taken to the bridge wing for recording sight times. In practice, a wrist watch coordinated to the nearest second with the chronometer will be adequate. [190] => [191] => A stop watch, either spring wound or digital, may also be used for celestial observations. In this case, the watch is started at a known GMT by chronometer, and the elapsed time of each sight added to this to obtain GMT of the sight. [192] => [193] => All chronometers and watches should be checked regularly with a radio time signal. Times and frequencies of radio time signals are listed in publications such as [[Radio Navigational Aids]]. [194] => [195] => ====The marine sextant==== [196] => [[File:Marine sextant.svg|thumb|upright=1.2|The marine [[sextant]] is used to measure the elevation of celestial bodies above the horizon.]] [197] => {{Further|Sextant}} [198] => The second critical component of celestial navigation is to measure the angle formed at the observer's eye between the celestial body and the sensible horizon. The sextant, an optical instrument, is used to perform this function. The sextant consists of two primary assemblies. The frame is a rigid triangular structure with a pivot at the top and a graduated segment of a circle, referred to as the "arc", at the bottom. The second component is the index arm, which is attached to the pivot at the top of the frame. At the bottom is an endless vernier which clamps into teeth on the bottom of the "arc". The optical system consists of two mirrors and, generally, a low power telescope. One mirror, referred to as the "index mirror" is fixed to the top of the index arm, over the pivot. As the index arm is moved, this mirror rotates, and the graduated scale on the arc indicates the measured angle ("altitude"). [199] => [200] => The second mirror, referred to as the "horizon glass", is fixed to the front of the frame. One half of the horizon glass is silvered and the other half is clear. Light from the celestial body strikes the index mirror and is reflected to the silvered portion of the horizon glass, then back to the observer's eye through the telescope. The observer manipulates the index arm so the reflected image of the body in the horizon glass is just resting on the visual horizon, seen through the clear side of the horizon glass. [201] => [202] => Adjustment of the sextant consists of checking and aligning all the optical elements to eliminate "index correction". Index correction should be checked, using the horizon or more preferably a star, each time the sextant is used. The practice of taking celestial observations from the deck of a rolling ship, often through cloud cover and with a hazy horizon, is by far the most challenging part of celestial navigation.{{Cite web |title=How Did Aviators "Shoot" the Sun and Stars? {{!}} Time and Navigation |url=http://timeandnavigation.si.edu/navigating-air/challenges/overcoming-challenges/celestial-navigation |access-date=2023-06-12 |website=timeandnavigation.si.edu |language=en}} [203] => [204] => ===Inertial navigation=== [205] => {{Further|Inertial navigation system}} [206] => [207] => [[Inertial navigation system]] (INS) is a [[dead reckoning]] type of navigation system that computes its position based on motion sensors. Before actually navigating, the initial latitude and longitude and the INS's physical orientation relative to the Earth (e.g., north and level) are established. After alignment, an INS receives impulses from motion detectors that measure (a) the acceleration along three axes (accelerometers), and (b) rate of rotation about three orthogonal axes (gyroscopes). These enable an INS to continually and accurately calculate its current latitude and longitude (and often velocity). [208] => [209] => Advantages over other navigation systems are that, once aligned, an INS does not require outside information. An INS is not affected by adverse weather conditions and it cannot be detected or jammed. Its disadvantage is that since the current position is calculated solely from previous positions and motion sensors, its errors are cumulative, increasing at a rate roughly proportional to the time since the initial position was input. Inertial navigation systems must therefore be frequently corrected with a location 'fix' from some other type of navigation system. [210] => [211] => The first inertial system is considered to be the V-2 guidance system deployed by the Germans in 1942. However, inertial sensors are traced to the early 19th century."An historical perspective on inertial navigation systems", Daniel Tazartes, ''2014 International Symposium on Inertial Sensors and Systems (ISISS)'', Laguna Beach, CA The advantages INSs led their use in aircraft, missiles, surface ships and submarines. For example, the U.S. Navy developed the Ships Inertial Navigation System (SINS) during the [[Polaris missile]] program to ensure a reliable and accurate navigation system to initial its missile guidance systems. Inertial navigation systems were in wide use until [[satellite navigation]] systems (GPS) became available. INSs are still in common use on submarines (since GPS reception or other fix sources are not possible while submerged) and long-range missiles. [212] => [213] => ==== Space navigation ==== [214] => Not to be confused with satellite navigation, which depends upon satellites to function, space navigation refers to the navigation of spacecraft themselves. This has historically been achieved (during the [[Apollo program]]) via a [[Apollo Guidance Computer|navigational computer]], an Inertial navigation system, and via celestial inputs entered by astronauts which were recorded by sextant and telescope. Space rated navigational computers, like those found on Apollo and later missions, are designed to be hardened against possible data corruption from radiation. [215] => [216] => Another possibility that has been explored for deep space navigation is [[Pulsar-based navigation|Pulsar navigation]], which compares the X-ray bursts from a collection of known pulsars in order to determine the position of a spacecraft. This method has been tested by multiple space agencies, such as [[NASA]] and [[European Space Agency|ESA]].{{Cite web |title=GSP Executive Summary |url=https://gsp.esa.int/documents/10192/43064675/C4000106174ExS.pdf/8a26a304-9d5f-447d-aa75-bc0c955a4b78 |url-status=dead |website=gsp.esa.int |access-date=2022-12-07 |archive-date=2017-03-16 |archive-url=https://web.archive.org/web/20170316044511/http://gsp.esa.int/documents/10192/43064675/C4000106174ExS.pdf/8a26a304-9d5f-447d-aa75-bc0c955a4b78 }}{{Cite web |author1=Rafi Letzter |date=2018-04-16 |title=NASA's Got a Plan for a 'Galactic Positioning System' to Save Astronauts Lost in Space |url=https://www.livescience.com/62309-galactic-positioning-system-nasa.html |access-date=2022-12-07 |website=livescience.com |language=en}} [217] => [218] => ===Electronic navigation=== [219] => [[File:Accuracy of Navigation Systems.svg|thumb|upright=1.2]] [220] => [221] => ====Radio navigation==== [222] => {{main|Radio navigation|Radio direction finder}} [223] => A radio direction finder or RDF is a device for finding the direction to a [[radio]] source. Due to radio's ability to travel very long distances "over the horizon", it makes a particularly good navigation system for ships and aircraft that might be flying at a distance from land. [224] => [225] => RDFs works by rotating a directional [[Antenna (electronics)|antenna]] and listening for the direction in which the signal from a known station comes through most strongly. This sort of system was widely used in the 1930s and 1940s. RDF antennas are easy to spot on [[Germany|German]] [[World War II]] aircraft, as loops under the rear section of the fuselage, whereas most [[United States|US]] aircraft enclosed the antenna in a small teardrop-shaped fairing. [226] => [227] => In navigational applications, RDF signals are provided in the form of ''radio beacons'', the radio version of a [[lighthouse]]. The signal is typically a simple [[Amplitude modulation|AM]] broadcast of a [[morse code]] series of letters, which the RDF can tune in to see if the beacon is "on the air". Most modern detectors can also tune in any commercial radio stations, which is particularly useful due to their high power and location near major cities. [228] => [229] => [[Decca Navigator System|Decca]], [[OMEGA Navigation System|OMEGA]], and [[LORAN-C]] are three similar hyperbolic navigation systems. Decca was a [[hyperbola|hyperbolic]] [[low frequency]] [[radio navigation]] system (also known as [[multilateration]]) that was first deployed during [[World War II]] when the Allied forces needed a system which could be used to achieve accurate landings. As was the case with [[Loran C]], its primary use was for ship navigation in coastal waters. Fishing vessels were major post-war users, but it was also used on aircraft, including a very early (1949) application of moving-map displays. The system was deployed in the North Sea and was used by helicopters operating to [[oil platform]]s. [230] => [231] => The OMEGA Navigation System was the first truly global [[radio navigation]] system for aircraft, operated by the [[United States]] in cooperation with six partner nations. OMEGA was developed by the United States Navy for military aviation users. It was approved for development in 1968 and promised a true worldwide oceanic coverage capability with only eight transmitters and the ability to achieve a four-mile (6 km) accuracy when fixing a position. Initially, the system was to be used for navigating nuclear bombers across the North Pole to Russia. Later, it was found useful for submarines.[http://www.jproc.ca/hyperbolic/omega.html Omega] Due to the success of the [[Global Positioning System]] the use of Omega declined during the 1990s, to a point where the cost of operating Omega could no longer be justified. Omega was terminated on September 30, 1997, and all stations ceased operation. [232] => [233] => LORAN is a terrestrial [[radio-navigation|navigation]] system using [[low frequency]] radio transmitters that use the time interval between radio signals received from three or more stations to determine the position of a ship or aircraft. The current version of LORAN in common use is LORAN-C, which operates in the [[low frequency]] portion of the EM spectrum from 90 to 110 [[Hertz|kHz]]. Many nations are users of the system, including the [[United States]], [[Japan]], and several European countries. Russia uses a nearly exact system in the same frequency range, called [[CHAYKA]]. LORAN use is in steep decline, with [[Global Positioning System|GPS]] being the primary replacement. However, there are attempts to enhance and re-popularize LORAN. LORAN signals are less susceptible to interference and can penetrate better into foliage and buildings than GPS signals. [234] => [235] => ====Radar navigation==== [236] => {{Further|Radar navigation|Doppler radar#navigation}} [237] => [[File:Navigation_system_on_a_merchant_ship_2.jpg|thumb|right|Radar ranges and bearings can be used to determine a position.]] [238] => [239] => Radar is an effective aid to navigation because it provides ranges and bearings to objects within range of the radar scanner.{{cite book | last = Anwar | first = Nadeem | title = Navigation Advanced for Mates and Masters | edition = 2nd | date = 2015 | publisher = [[Witherby Publishing Group]] | location = Edinburgh | pages=133-139 |isbn = 978-1-85609-627-0}} When a vessel (ship or boat) is within radar range of land or fixed objects (such as special radar aids to navigation and navigation marks) 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. Types of radar fixes include "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." Radar can also be used with [[ECDIS]] as a means of position fixing with the radar image or distance/bearing overlaid onto an [[Electronic navigational chart|Electronic nautical chart]]. [240] => [241] => 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 parallel line allows the navigator to maintain a given distance away from hazards. The line on the radar screen is set to a specific distance and angle, then the ship's position relative to the parallel line is observed. This can provide an immediate reference to the navigator as to whether the ship is on or off its intended course for navigation.{{cite book | last = Victor| first = Alain| title = Parallel Index Techniques in Restricted Waters -| edition = 2nd | date = 2020 | publisher = [[Witherby Publishing Group]] | location = Edinburgh |isbn = 9781856099165}} [242] => [243] => Other techniques that are less used in general navigation have been developed for special situations. One, known as the "contour method," involves marking a transparent plastic template on the radar screen and moving it to the chart to fix a position.National Imagery and Mapping Agency, 2001:164. Another special technique, known as the Franklin Continuous Radar Plot Technique, involves drawing the path a radar object should follow on the radar display if the ship stays on its planned course.National Imagery and Mapping Agency, 2001:182. During the transit, the navigator can check that the ship is on track by checking that the pip lies on the drawn line. [244] => [245] => ====Satellite navigation==== [246] => {{Further|Satellite navigation}} [247] => Global Navigation Satellite System or GNSS is the term for satellite navigation systems that provide positioning with global coverage. A GNSS allow small [[electronics|electronic]] receivers to determine their location ([[longitude]], [[latitude]], and [[altitude]]) within a few meters using [[time signal]]s transmitted along a [[Line-of-sight propagation|line of sight]] by [[radio]] from [[satellite]]s. Receivers on the ground with a fixed position can also be used to calculate the precise time as a reference for scientific experiments. [248] => [249] => As of October 2011, only the [[United States]] NAVSTAR [[Global Positioning System]] (GPS) and the [[Russia]]n [[GLONASS]] are fully globally operational GNSSs. The [[European Union]]'s [[Galileo positioning system]] is a next generation GNSS in the final deployment phase, and became operational in 2016. [[China]] has indicated it may expand its regional [[Beidou navigation system]] into a global system. [250] => [251] => More than two dozen GPS satellites are in [[medium Earth orbit]], transmitting signals allowing GPS receivers to determine the receiver's [[geographic location|location]], speed and direction. [252] => [253] => Since the first experimental satellite was launched in 1978, GPS has become an indispensable aid to navigation around the world, and an important tool for [[cartography|map-making]] and [[surveying|land surveying]]. GPS also provides a precise [[time transfer|time reference]] used in many applications including scientific study of [[earthquake]]s, and [[synchronization]] of telecommunications networks. [254] => [255] => Developed by the [[United States Department of Defense]], GPS is officially named NAVSTAR GPS (NAVigation Satellite Timing And Ranging Global Positioning System). The [[satellite constellation]] is managed by the [[United States Air Force]] [[50th Space Wing]]. The cost of maintaining the system is approximately [[United States dollar|US$]]750 million per year,[http://gps.losangeles.af.mil/jpo/gpsoverview.htm GPS Overview from the NAVSTAR Joint Program Office] {{webarchive|url=https://web.archive.org/web/20060928042828/http://gps.losangeles.af.mil/jpo/gpsoverview.htm |date=2006-09-28 }}. Accessed December 15, 2006. including the replacement of aging satellites, and research and development. Despite this fact, GPS is free for civilian use as a [[Public good (economics)|public good]]. [256] => [257] => Modern [[smartphones]] act as personal [[GPS]] navigators for civilians who own them. Overuse of these devices, whether in the vehicle or on foot, can lead to a relative inability to learn about navigated environments, resulting in sub-optimal navigation abilities when and if these devices become unavailable.{{Cite journal|last=Gardony|first=Aaron L|date=April 2013|title=How Navigational Aids Impair Spatial Memory: Evidence for Divided Attention|journal=Spatial Cognition & Computation|volume=13|issue=4|pages=319–350|doi=10.1080/13875868.2013.792821|s2cid=7905481}}{{Cite journal|last=Gardony|first=Aaron L.|date=June 2015|title=Navigational Aids and Spatial Memory Impairment: The Role of Divided Attention|journal=Spatial Cognition & Computation|volume=15|issue=4|pages=246–284|doi=10.1080/13875868.2015.1059432|s2cid=42070277}}{{Cite book|title=Spatial Information Theory|last=Winter|first=Stephen|publisher=Springer Berlin|year=2007|isbn=978-3540747888|location=Heidelberg, Germany|pages=238–254}} Typically a [[compass]] is also provided to determine direction when not moving. [258] => [259] => ==== Acoustic navigation ==== [260] => {{main|Sonar|Acoustic location}} [261] => {{expand section|date=March 2020}} [262] => [263] => ==Navigation processes== [264] => [265] => ===Ships and similar vessels=== [266] => ====One day's work in navigation==== [267] => The day's work in navigation is a minimal set of tasks consistent with prudent navigation. The definition will vary on military and civilian vessels, and from ship to ship, but the traditional method takes a form resembling:Turpin and McEwen, 1980:6–18. [268] => # Maintain a continuous dead reckoning plot. [269] => # Take two or more star observations at morning twilight for a celestial fix (prudent to observe six stars). [270] => # Morning Sun observation. Can be taken on or near [[prime vertical]] for longitude, or at any time for a line of position. [271] => # Determine compass error by azimuth observation of the Sun. [272] => # Computation of the interval to noon, watch time of local apparent noon, and constants for meridian or ex-meridian sights. [273] => # Noontime meridian or ex-meridian observation of the Sun for noon latitude line. Running fix or cross with Venus line for noon fix. [274] => # Noontime determination the day's run and day's set and drift. [275] => # At least one afternoon Sun line, in case the stars are not visible at twilight. [276] => # Determine compass error by azimuth observation of the Sun. [277] => # Take two or more star observations at evening twilight for a celestial fix (prudent to observe six stars). [278] => [279] => Navigation on ships is usually always conducted on the [[Bridge (nautical)#Navigation station|bridge]]. It may also take place in adjacent space, where chart tables and publications are available. [280] => [281] => ====Passage planning==== [282] => {{Main|Passage planning}} [283] => [[File:Exval.jpeg|thumb|right|Poor passage planning and deviation from the plan can lead to groundings, ship damage and cargo loss.]]Passage planning or voyage planning is a procedure to develop a complete description of vessel's voyage from start to finish. The plan includes leaving the dock and harbor area, the en route portion of a voyage, approaching the destination, and [[Mooring (watercraft)|mooring]]. According to international law, a vessel's [[captain (nautical)|captain]] is legally responsible for passage planning,{{cite web [284] => | title = Regulation 34 – Safe Navigation [285] => | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Regulations/regulation34.htm [286] => | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999 [287] => | access-date=March 26, 2007}} however on larger vessels, the task will be delegated to the ship's [[navigator]].{{cite web [288] => | title = ANNEX 24 – MCA Guidance Notes for Voyage Planning [289] => | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex24.htm [290] => | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999 [291] => | access-date=March 26, 2007}} [292] => [293] => Studies show that [[human error]] is a factor in 80 percent of navigational accidents and that in many cases the human making the error had access to information that could have prevented the accident. The practice of voyage planning has evolved from penciling lines on [[nautical chart]]s to a process of [[risk management]]. [294] => [295] => Passage planning consists of four stages: appraisal, planning, execution, and monitoring, which are specified in ''[[International Maritime Organization]] Resolution A.893(21), Guidelines For Voyage Planning,''{{cite web [296] => | title = ANNEX 25 – MCA Guidance Notes for Voyage Planning [297] => | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex25.htm [298] => | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999 [299] => | access-date=January 28, 2011}} and these guidelines are reflected in the local laws of IMO signatory countries (for example, Title 33 of the U.S. [[Code of Federal Regulations]]), and a number of professional books or publications. There are some fifty elements of a comprehensive passage plan depending on the size and type of vessel. [300] => [301] => The appraisal stage deals with the collection of information relevant to the proposed voyage as well as ascertaining risks and assessing the key features of the voyage. This will involve considering the type of navigation required e.g. [[Ice navigation]], the region the ship will be passing through and the [[hydrography|hydrographic]] information on the route. In the next stage, the written plan is created. The third stage is the execution of the finalised voyage plan, taking into account any special circumstances which may arise such as changes in the weather, which may require the plan to be reviewed or altered. The final stage of passage planning consists of monitoring the vessel's progress in relation to the plan and responding to deviations and unforeseen circumstances. [302] => [303] => ====Integrated bridge systems==== [304] => [[File:Integriertes Brückensystem.jpg|thumb|Integrated Bridge System, integrated on an Offshore Service Ship]] [305] => Electronic integrated bridge concepts are driving future navigation system planning. Integrated systems take inputs from various ship sensors, electronically display positioning information, and provide control signals required to maintain a vessel on a preset course. The navigator becomes a system manager, choosing system presets, interpreting system output, and monitoring vessel response. [306] => [307] => ===Land navigation=== [308] => Navigation for cars and other land-based travel typically uses [[map]]s, [[landmark]]s, and in recent times [[Navigation system|computer navigation]] ("[[satnav]]", short for satellite navigation), as well as any means available on water. [309] => [310] => Computerized navigation commonly relies on [[GPS]] for current location information, a [[electronic map|navigational map database]] of roads and navigable routes, and uses [[algorithm]]s related to the [[shortest path problem]] to identify optimal routes. [311] => [312] => Pedestrian navigation is involved in [[orienteering]], [[Land navigation|land navigation (military)]], and [[wayfinding]]. [313] => [314] => ===Underwater navigation=== [315] => {{main|Diver navigation|Submarine navigation}} [316] => [317] => ==Standards, training and organisations== [318] => [319] => Professional standards for navigation depend on the type of navigation and vary by country. For marine navigation, [[Merchant Navy]] [[Deck department|deck officers]] are trained and internationally certified according to the [[STCW Convention]].{{cite book |title=Standards of Training and Certification of Watchkeeping' (STCW) Convention |publisher= [[International Maritime Organization]]|date= 2010 }} Leisure and amateur mariners may undertake lessons in navigation at local/regional training schools. [[Navy|Naval]] officers receive navigation training as part of their naval training. [320] => [321] => In land navigation, courses and training is often provided to young persons as part of general or extra-curricular education. Land navigation is also an essential part of army training. Additionally, organisations such as the [[Scouting|Scouts]] and [[The Duke of Edinburgh's Award|DoE programme]] teach navigation to their students. [[Orienteering]] organisations are a type of sports that require navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain whilst moving at speed.{{cite web [322] => |url = http://www.orienteering.ca/about_orienteering.htm [323] => |title = About Orienteering [324] => |publisher = The Canadian Orienteering Federation [325] => |access-date = 2008-08-11 [326] => |url-status = dead [327] => |archive-url = https://web.archive.org/web/20081002091244/http://www.orienteering.ca/about_orienteering.htm [328] => |archive-date = 2008-10-02 [329] => }} [330] => [331] => In aviation, pilots undertake [[air navigation]] training as part of learning to fly. [332] => [333] => Professional organisations also assist to encourage improvements in navigation or bring together navigators in learned environments. The [[Royal Institute of Navigation]] (RIN) is a [[learned society]] with charitable status, aimed at furthering the development of navigation on land and sea, in the air and in space. It was founded in 1947 as a forum for mariners, pilots, engineers and academics to compare their experiences and exchange information.{{Cite journal|year=2016|title=The Royal Institute of Navigation - Aims and Objects|journal=Journal of Navigation|volume=69|issue=66|pages= b1–b2 }} In the US, the [[Institute of Navigation]] (ION) is a non-profit professional organisation advancing the art and science of positioning, navigation and timing.{{cite web [334] => | title = The Institute of Navigation [335] => | url = https://www.ion.org/about/index.cfm [336] => | access-date=February 6, 2020}} [337] => [338] => ===Publications=== [339] => [[File:Bowditch 1910 Figure 2 Compass Rose navigatorpracti00bowdrich 0021.jpg|thumb|right|An illustration showing a compass used for navigation from Bowditch's American Practical Navigator]] [340] => Numerous [[nautical publications]] are available on navigation, which are published by professional sources all over the world. In the UK, the [[United Kingdom Hydrographic Office]], the [[Witherby Publishing Group]] and the [[Nautical Institute]] provide numerous navigational publications, including the comprehensive Admiralty Manual of Navigation.{{cite web [341] => | title = The Admiralty Manual of Navigation [342] => | publisher = The Nautical Institute [343] => | url = https://www.nautinst.org/shop/the-admiralty-manual-of-navigation-vol-1-principles-of-navigation.html [344] => | access-date=February 6, 2020}}{{cite web [345] => | title = Navigation Publications [346] => | publisher = Witherby Publishing Group [347] => | url = https://www.witherbyseamanship.com/categories/navigation.html [348] => | access-date=February 6, 2020}} [349] => [350] => In the US, [[Bowditch's American Practical Navigator]] is a free available encyclopedia of navigation issued by the US Government.{{cite web [351] => | title = The American Practical Navigator [352] => | url = https://en.wikisource.org/wiki/The_American_Practical_Navigator [353] => | access-date=February 6, 2020}} [354] => [355] => ==Navigation in spatial cognition== [356] => Navigation is an essential everyday activity that involves a series of abilities that help humans and animals to locate, track, and follow paths in order to arrive at different destinations.{{Cite journal |date=November 2017 |title=Focus on spatial cognition |url=https://www.nature.com/articles/nn.4666 |journal=Nature Neuroscience |language=en |volume=20 |issue=11 |pages=1431 |doi=10.1038/nn.4666 |pmid=29073640 |s2cid=205441391 |issn=1546-1726}}{{Cite journal |last1=Wolbers |first1=Thomas |last2=Hegarty |first2=Mary |date=March 2010 |title=What determines our navigational abilities? |url=https://linkinghub.elsevier.com/retrieve/pii/S1364661310000021 |journal=Trends in Cognitive Sciences |language=en |volume=14 |issue=3 |pages=138–146 |doi=10.1016/j.tics.2010.01.001|pmid=20138795 |s2cid=15142890 }} Navigation, in [[spatial cognition]], allows for acquiring information about the environment by using the body and [[Landmark|landmarks]] of the environment as [[Frame of reference|frames of references]] to create [[Mental representation|mental representations]] of our environment, also known as a [[cognitive map]]. Humans navigate by transitioning between different spaces and coordinating both [[Frame of reference|egocentric and allocentric frames of reference]]. [357] => [358] => Navigation can be distinguished into two sptial components: locomotion and wayfinding.{{Citation |last=Montello |first=Daniel R. |title=Navigation |date=2005-07-18 |url=https://www.cambridge.org/core/product/identifier/9780511610448%23c80710-dcz-s9i-re2-gh5/type/book_part |work=The Cambridge Handbook of Visuospatial Thinking |pages=257–294 |editor-last=Shah |editor-first=Priti |edition=1 |publisher=Cambridge University Press |doi=10.1017/cbo9780511610448.008 |isbn=978-0-511-61044-8 |access-date=2022-05-06 |editor2-last=Miyake |editor2-first=Akira}} Locomotion is the process of movement from one place to another, both in humans and in animals. Locomotion helps you understand an environment by moving through a space in order to create a mental representation of it.{{Cite web |title=APA Dictionary of Psychology/Locomotion |url=https://dictionary.apa.org/locomotion |access-date=2022-05-06 |website=dictionary.apa.org |language=en}} [[Wayfinding]] is defined as an active process of following or deciding upon a path between one place to another through mental representations.{{Cite journal |last=GOLLEDGE |first=Reginald G. |date=December 2000 |title=Cognitive Maps, Spatial Abilities, and Human Wayfinding |url=https://mural.maynoothuniversity.ie/7262/1/RK-Cognitive.pdf |journal=Geographical Review of Japan |volume=73 |pages=93–104}} It involves processes such as representation, planning and decision which help to avoid obstacles, to stay on course or to regulate pace when approaching particular objects.{{Cite journal |last=Tolman |first=Edward C. |date=1948 |title=Cognitive maps in rats and men. |url=http://doi.apa.org/getdoi.cfm?doi=10.1037/h0061626 |journal=Psychological Review |language=en |volume=55 |issue=4 |pages=189–208 |doi=10.1037/h0061626 |pmid=18870876 |issn=1939-1471}} [359] => [360] => Navigation and wayfinding can be approached in the [[Spatial cognition|environmental space]]. According to [[Daniel R. Montello|Dan Montello]]’s [[Spatial cognition|space classification]], there are four levels of space with the third being the environmental space. The environmental space represents a very large space, like a city, and can only be fully explored through movement since all objects and space are not directly visible.{{Cite book |last=Denis |first=Michel |url=https://www.taylorfrancis.com/books/9781351596183 |title=Space and Spatial Cognition: A Multidisciplinary Perspective |date=2017-11-13 |publisher=Routledge |isbn=978-1-315-10380-8 |edition=1 |language=en |doi=10.4324/9781315103808}} Also [[Barbara Tversky]] systematized the space, but this time taking into consideration the three dimensions that correspond to the [[Axis (anatomy)|axes]] of the human body and its extensions: above/below, front/back and left/right. Tversky ultimately proposed a fourfold classification of navigable space: space of the body, space around the body, space of navigation and space of graphics.{{Cite journal |last=Tversky |first=Barbara |date=January 2003 |title=Structures Of Mental Spaces: How People Think About Space |url=http://journals.sagepub.com/doi/10.1177/0013916502238865 |journal=Environment and Behavior |language=en |volume=35 |issue=1 |pages=66–80 |doi=10.1177/0013916502238865 |s2cid=16647328 |issn=0013-9165}} [361] => [362] => ===Wayfinding=== [363] => There are two types of wayfinding in navigation: aided and unaided. Aided wayfinding requires a person to use various types of [[Media (communication)|media]], such as [[Map|maps]], [[Global Positioning System|GPS]], [[Direction, position, or indication sign|directional signage]], etc., in their navigation process which generally involves low spatial reasoning and is less cognitively demanding. Unaided wayfinding involves no such devices for the person who is navigating. Unaided wayfinding can be subdivided into a [[taxonomy]] of tasks depending on whether it is undirected or directed, which basically makes the distinction of whether there is a precise destination or not: undirected wayfinding means that a person is simply [[Exploration|exploring]] an environment for pleasure without any set destination.{{Cite journal |last1=Wiener |first1=Jan M. |last2=Büchner |first2=Simon J. |last3=Hölscher |first3=Christoph |date=2009-05-20 |title=Taxonomy of Human Wayfinding Tasks: A Knowledge-Based Approach |url=http://www.tandfonline.com/doi/abs/10.1080/13875860902906496 |journal=Spatial Cognition & Computation |language=en |volume=9 |issue=2 |pages=152–165 |doi=10.1080/13875860902906496 |s2cid=16529538 |issn=1387-5868}} [364] => [365] => Directed wayfinding, instead, can be further subdivided into search vs. target approximation. Search means that a person does not know where the destination is located and must find it either in an unfamiliar environment, which is labeled as an uninformed search, or in a familiar environment, labeled as an informed search. In target approximation, on the other hand, the location of the destination is known to the navigator but a further distinction is made based on whether the navigator knows how to arrive or not to the destination. Path following means that the environment, the path, and the destination are all known which means that the navigator simply follows the path they already know and arrive at the destination without much thought. For example, when you are in your city and walking on the same path as you normally take from your house to your job or university. However, path finding means that the navigator knows where the destination is but does not know the route they have to take to arrive at the destination: you know where a specific store is but you do not know how to arrive there or what path to take. If the navigator does not know the environment, it is called path search which means that only the destination is known while neither the path nor the environment is: you are in a new city and need to arrive at the train station but do not know how to get there. Path planning, on the other hand, means that the navigator knows both where the destination is and is familiar with the environment so they only need to plan the route or path that they should take to arrive at their target. For example, if you are in your city and need to get to a specific store that you know the destination of but do not know the specific path you need to take to get there. [366] => [367] => == See also == [368] => {{Portal|Geography}} [369] => * [[Robot navigation]] [370] => * [[TVMDC]] [371] => * [[Collision avoidance in transportation]] [372] => * [[Spatial cognition#Navigation]] [373] => [374] => ==Notes== [375] => {{Reflist}} [376] => [377] => ==References== [378] => {{refbegin}} [379] => * [https://en.wikisource.org/wiki/ Nathaniel Bowditch, ''The American Practical Navigator,'' (2002) by the United States government] [380] => * {{cite book | last = Anwar | first = Nadeem | title = Navigation Advanced for Mates and Masters | edition = 2nd | date = 2015 | publisher = [[Witherby Publishing Group]] | location = Edinburgh | isbn = 978-1-85609-627-0}} [381] => * {{cite book [382] => | last = Cutler [383] => | first = Thomas J. [384] => | title = Dutton's Nautical Navigation [385] => | edition = 15th [386] => | date = December 2003 [387] => | publisher = Naval Institute Press [388] => | location = Annapolis, MD [389] => | isbn = 978-1-55750-248-3 [390] => }} [391] => * {{cite book| author =Department of the Air Force| author-link =United States Air Force| title =Air Navigation| url =http://www.e-publishing.af.mil/pubfiles/af/11/afpam11-216/afpam11-216.pdf| access-date =2007-04-17| date =March 2001| publisher =Department of the Air Force| url-status=dead| archive-url =https://web.archive.org/web/20070325022639/http://www.e-publishing.af.mil/pubfiles/af/11/afpam11-216/afpam11-216.pdf| archive-date =2007-03-25}} [392] => * {{cite book [393] => | last = Great Britain Ministry of Defence (Navy) [394] => | title = Admiralty Manual of Seamanship [395] => | publisher = [[The Stationery Office]] [396] => | year = 1995 [397] => | isbn = 978-0-11-772696-3 [398] => }} [399] => * {{cite book | last=Gilardoni | first=Eduardo O. | last2=Presedo | first2=Juan P. | title=Navigation in Shallow Waters | publisher=Witherbys | publication-place=Livingston, Scotland | date=2017 | isbn=978-1-85609-667-6}} [400] => * {{cite book|author1=Bernhard Hofmann-Wellenhof|author2=K. Legat|author3=M. Wieser|title=Navigation: principles of positioning and guidance|url=https://books.google.com/books?id=losWr9UDRasC|access-date=7 February 2012|year=2003|publisher=Springer|isbn=978-3-211-00828-7}} [401] => * {{cite book [402] => | last = Maloney [403] => | first = Elbert S. [404] => | title = Chapman Piloting and Seamanship [405] => | url = https://archive.org/details/chapmanpilotings00elbe_1 [406] => | edition = 64th [407] => | date = December 2003 [408] => | publisher = Hearst Communications Inc. [409] => | location = New York [410] => | isbn = 978-1-58816-089-8 [411] => | url-access = registration [412] => }} [413] => * {{cite book [414] => |author=National Imagery and Mapping Agency [415] => |author-link=National Imagery and Mapping Agency [416] => |title=Publication 1310: Radar Navigation and Maneuvering Board Manual [417] => |url=http://www.nga.mil/portal/site/maritime/ [418] => |format=PDF [419] => |edition=7th [420] => |year=2001 [421] => |publisher=U.S. Government Printing Office [422] => |location=Bethesda, MD [423] => |url-status=dead [424] => |archive-url=https://web.archive.org/web/20070307132409/http://www.nga.mil/portal/site/maritime/ [425] => |archive-date=2007-03-07 [426] => }} [427] => * {{cite book [428] => | last = Turpin [429] => | first = Edward A. [430] => | author2 = McEwen, William A. [431] => | title = Merchant Marine Officers' Handbook [432] => | edition = 4th [433] => | year = 1980 [434] => | publisher = Cornell Maritime Press [435] => | location = Centreville, MD [436] => | isbn = 978-0-87033-056-8 [437] => }} [438] => * {{Cite EB1911|wstitle=Navigation|volume=19|pages=284–298|first=William Robert|last=Martin}} [439] => * {{Cite EB1911|wstitle=Pytheas|volume=22|pages=703–704|first1=Edward Herbert|last1=Bunbury|author-link=Edward Bunbury|first2=Charles Raymond|last2=Beazley|author-link2=Raymond Beazley}} [440] => * {{Citation | last1 =Raol| first1 =Jitendra | last2 =Gopal | first2 =Ajith | year =2013 | title =Mobile Intelligent Autonomous Systems | url = https://books.google.com/books?id=HaS91phGuRQC&q=sanskrit+navgati&pg=PA141 | publisher = CRC Press Taylor and Francis Group |location=Boca Raton, FL | isbn =978-1-4398-6300-8 }} [441] => {{refend}} [442] => [443] => ==External links== [444] => {{wikiquote}} [445] => {{Commons}} [446] => {{Wikisource|Portal:Navigation}} [447] => {{Wikivoyage}} [448] => * [https://www.gutenberg.org/ebooks/27642 ''Lectures in Navigation''] by Ernest Gallaudet Draper [449] => * [https://archive.today/20121208170816/http://alsworld.topcities.com/bwgg/index.html How to navigate with less than a compass or GPS] (archived 8 December 2012) [450] => [451] => {{Geodesy navbox|state=uncollapsed}} [452] => {{Orienteering|type=collapsed}} [453] => {{Seamanship}} [454] => {{Satellite navigation systems}} [455] => [456] => {{Authority control}} [457] => [458] => [[Category:Navigation| ]] [459] => [[Category:Geodesy]] [] => )
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Navigation

Navigation refers to the process of directing or guiding oneself through a physical or digital environment in order to reach a particular destination or desired outcome. In the context of Wikipedia, navigation is crucial for users to effectively explore and access the vast amount of information available on the site.

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In the context of Wikipedia, navigation is crucial for users to effectively explore and access the vast amount of information available on the site. The Wikipedia page on navigation provides an overview of the various tools and features available on the platform that assist users in finding and navigating through articles. It explains the different types of navigation methods, such as internal links, categories, and search functionality, that help users locate relevant articles and move between related topics. The page also highlights the importance of clear and consistent navigation in enhancing user experience and facilitating knowledge discovery. It discusses the role of site structure, menus, and navigation templates in organizing and presenting content in a logical and intuitive manner. Additionally, it outlines the concept of "navigation bars" as a common feature present on Wikipedia pages, providing quick access to essential links and tools. Furthermore, the page delves into more advanced navigation techniques used by experienced Wikipedia editors. It covers topics such as the use of transclusion, navigation templates, and templates for related articles, as well as the creation of custom navigation aids to enhance article navigation. Overall, the Wikipedia page on navigation serves as a comprehensive guide to understanding the various navigation tools and principles employed on the platform. It is a useful resource for both novice and experienced users, as it provides insights into effective navigation strategies and techniques for exploring and contributing to the world's largest online encyclopedia.

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