203:. Since all physical observations are subject to errors, the resulting position fix is also subject to inaccuracy. Although in theory two lines of position (LOP) are enough to define a point, in practice 'crossing' more LOPs provides greater accuracy and confidence, especially if the lines cross at a good angle to each other. Three LOPs are considered the minimum for a practical navigational fix. The three LOPs when drawn on the chart will in general form a triangle, known as a 'cocked hat'. The navigator will have more confidence in a position fix that is formed by a small cocked hat with angles close to those of an
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Though these processes are closely related and are part of the broader concept of location-based technologies, they are distinct in their specific applications and functions. While geolocation typically provides a set of coordinates to localize an asset on a reference plan or on a map, geofencing can
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Usually, a fix is where two or more position lines intersect at any given time. If three position lines can be obtained, the resulting "cocked hat", where the three lines do not intersect at the same point, but create a triangle, gives the navigator an indication of the accuracy. The most accurate
326:
and to indoor positioning, for all the situations where satellite GPS is not a viable option and the localization process has to happen indoors. For indoor positioning, tracking and localization there are many technologies that can be used, depending on the specific needs and on the environmental
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generally refers to the identification or estimation of the real-world geographic location of an object, often specifically in the context of digital or electronic systems, such as determining the location of a computer, mobile device, or network node.
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indicator. Two or more objects of known position are sighted, and the bearings recorded. Bearing lines are then plotted on a chart through the locations of the sighted items. The intersection of these lines is the current position of the vessel.
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The calculation requires measurements or observations of distances or angles to reference points whose positions are known. In 2D surveys, observations of three reference points are enough to compute a position in a
308:. The fix confirms the actual position during a journey. A fix can introduce inaccuracies if the reference point is not correctly identified or is inaccurately measured.
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plane. In practice, observations are subject to errors resulting from various physical and atmospheric factors that influence the measurement of distances and angles.
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64:; positions may also be expressed as a bearing and range from a known landmark. In turn, positions can determine a meaningful location, such as a
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Brena, Ramon F.; García-Vázquez, Juan Pablo; Galván-Tejada, Carlos E.; Muñoz-Rodriguez, David; Vargas-Rosales, Cesar; Fangmeyer, James (2017).
219:. As more redundant reference points are added, the position fix becomes more accurate and the area of the resulting error ellipse decreases.
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287:; in aviation, use of electronic navigation aids is more common. A visual fix can be made by using any sighting device with a
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in order to compute a position fix in 3D space. This is most commonly done by combining distance measurements to 4 or more
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fixes occur when the position lines are perpendicular to each other. Fixes are a necessary aspect of navigation by
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279:, the term is generally used with manual or visual techniques, such as the use of intersecting visual or radio
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668:. Advances in Computer Vision and Pattern Recognition (in Romanian). Springer International Publishing.
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Geopositioning can be referred to both global positioning and outdoor positioning, using for example
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systems generally use more than three reference points to compute a position fix to increase the
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Combining multiple observations to compute a position fix is equivalent to solving a system of
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275:, a position derived from measuring in relation to external reference points. In nautical
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While these terms are often used interchangeably, they have slightly different meanings.
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positioned along the coast. These measurements could be made visually using a
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The process of using 3 reference points to calculate the location is called
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A practical example of obtaining a position fix would be for a ship to take
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Zamir, A.R.; Hakeem, A.; Van Gool, L.; Shah, M.; Szeliski, R. (2016).
124:, on the other hand, involves creating a virtual geographic boundary (
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Identification of the real-world geographic position of an object
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Munoz, D.; Lara, F.B.; Vargas, C.; Enriquez-Caldera, R. (2009).
486:"What is geofencing and how is it used? – TechTarget Definition"
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Keating, J.B.; United States. Bureau of Land
Management (1993).
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207:. The area of doubt surrounding a position fix is called an
110:, and the process may also be described as geo-localization.
753:
Handbook of
Position Location: Theory, Practice, and Advances
602:
Nait-Sidi-Moh, A.; Bakhouya, M.; Gaber, J.; Wack, M. (2013).
78:, the process of inferring the location of animals over time;
756:. IEEE Series on Digital & Mobile Communication. Wiley.
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The Geo-Positioning
Selection Guide for Resource Management
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Gentile, C.; Alsindi, N.; Raulefs, R.; Teolis, C. (2012).
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B. Hofmann-Wellenhof; K. Legat; M. Wieser (28 June 2011).
467:. BLM technical note. Bureau of Land Management. p. 5
697:"Evolution of Indoor Positioning Technologies: A Survey"
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Visual fix by three bearings plotted on a nautical chart
195:, or in case of poor visibility, electronically using
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Geolocation
Techniques: Principles and Applications
512:Navigation: Principles of Positioning and Guidance
90:, geolocating a device connected to the internet;
41:is the process of determining or estimating the
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780:Position Location Techniques and Applications
8:
635:Laurie Tetley; David Calcutt (7 June 2007).
252:, which orbit the Earth along known paths.
106:Geopositioning is sometimes referred to as
102:Geopositioning, Geolocation, and Geofencing
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263:The result of position fixing is called a
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515:. Springer Science & Business Media.
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144:Geopositioning uses various visual and
226:, and when using more than 3 points,
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750:Zekavat, R.; Buehrer, R.M. (2019).
665:Large-Scale Visual Geo-Localization
166:radio and WiFi positioning systems,
34:Principles of geolocation using GPS
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300:, which relies on estimates of
48:Geopositioning yields a set of
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638:Electronic Navigation Systems
408:Vertical position measurement
398:Satellite navigation software
71:Specific instances include:
170:satellite navigation systems
999:Precession of the equinoxes
608:. ISTE. Wiley. p. 71.
605:Geopositioning and Mobility
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641:. Routledge. pp. 9–.
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45:of an object or a person.
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318:Indoor positioning system
237:. Navigation systems use
211:. To minimize the error,
136:or a in/out information.
388:Longitude determination
338:Direction determination
201:radio direction finding
393:Location-based service
383:Latitude determination
260:
187:measurements on three
50:geographic coordinates
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18:Geographic positioning
979:Earth's gravity field
974:Earth's energy budget
575:. Springer New York.
542:. Springer New York.
312:Indoor Geopositioning
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239:regression algorithms
213:electronic navigation
95:mobile phone tracking
33:
894:Computer cartography
819:at Wikimedia Commons
783:. Elsevier Science.
714:10.1155/2017/2630413
358:Geodetic positioning
205:equilateral triangle
193:hand bearing compass
158:celestial navigation
88:internet geolocation
1013:Related disciplines
569:Progri, I. (2011).
413:W3C Geolocation API
343:Dynamic positioning
132:simply provide the
43:geographic position
1061:Geodesy portal
911:Geodetic astronomy
701:Journal of Sensors
378:Indoor positioning
327:characteristics.
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148:methods including
82:positioning system
76:animal geotracking
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615:978-1-118-74368-3
582:978-1-4419-7952-0
549:978-1-4614-1836-8
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363:GPS tracking unit
134:range of distance
16:(Redirected from
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443:. 2020-06-02
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348:Geo-blocking
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889:Cartography
817:Geolocation
189:lighthouses
115:Geolocation
108:geolocation
1101:Categories
1030:Geophysics
926:Navigation
873:Geodesists
796:2021-02-19
769:2021-02-19
681:2020-08-31
621:2020-08-31
588:2020-08-31
555:2020-08-31
495:2024-09-10
471:2020-08-31
447:2020-08-31
439:ISO/TC 211
420:References
368:Geotagging
277:navigation
250:satellites
146:electronic
140:Background
122:Geofencing
1020:Astronomy
984:Geodynamo
957:phenomena
955:Physical
916:Geomatics
882:Subfields
733:1687-725X
441:Geolexica
353:Geocoding
62:map datum
58:longitude
52:(such as
1073:Category
861:Overview
707:: 1–21.
331:See also
241:such as
126:Geofence
54:latitude
1112:Geodesy
1085:Commons
1040:Physics
1025:Geology
868:History
854:Geodesy
289:bearing
185:bearing
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490:WhatIs
306:course
302:speed
197:radar
1004:Tide
785:ISBN
758:ISBN
729:ISSN
705:2017
670:ISBN
643:ISBN
610:ISBN
577:ISBN
544:ISBN
517:ISBN
324:GPS,
304:and
152:and
93:and
56:and
719:hdl
709:doi
285:GPS
273:fix
247:GPS
199:or
1103::
727:.
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269:PF
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