Editing Navigation (section)

==Navigation processes==
=== Passage planning ===
{{Main|Passage planning}}
[[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,<ref name="reg34">{{cite web
 | title = Regulation 34 – Safe Navigation
 | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Regulations/regulation34.htm
 | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999
 | access-date = March 26, 2007
 | archive-date = 27 September 2007
 | archive-url = https://web.archive.org/web/20070927002958/https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Regulations/regulation34.htm
 | url-status = dead
 }}</ref> however on larger vessels, the task will be delegated to the ship's [[navigator]].<ref name="annex24">{{cite web
 | title = ANNEX 24 – MCA Guidance Notes for Voyage Planning
 | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex24.htm
 | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999
 | access-date = March 26, 2007
 | archive-date = 27 September 2007
 | archive-url = https://web.archive.org/web/20070927002748/https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex24.htm
 | url-status = dead
 }}</ref>

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.<ref name="annex24"/> The practice of voyage planning has evolved from penciling lines on [[nautical chart]]s to a process of [[risk management]].<ref name="annex24"/>

Passage planning consists of four stages: appraisal, planning, execution, and monitoring,<ref name="annex24"/> which are specified in ''[[International Maritime Organization]] Resolution A.893(21), Guidelines For Voyage Planning,''<ref name="annex25">{{cite web
 | title = ANNEX 25 – MCA Guidance Notes for Voyage Planning
 | url = https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex25.htm
 | work = IMO RESOLUTION A.893(21) adopted on 25 November 1999
 | access-date = January 28, 2011
 | archive-date = 24 July 2011
 | archive-url = https://web.archive.org/web/20110724014258/https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex25.htm
 | url-status = dead
 }}</ref> 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.

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.

=== Integrated bridge systems ===
[[File:Integriertes Brückensystem.jpg|thumb|Integrated Bridge System, integrated on an Offshore Service Ship]]
Electronic integrated bridge concepts are driving future navigation system planning.<ref name="bow1"/> 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.<ref name="bow1"/> The navigator becomes a system manager, choosing system presets, interpreting system output, and monitoring vessel response.<ref name="bow1"/>

[[File:Two ship's officers 'shoot' in one morning with the sextant, the sun altitude.jpg|thumb|Two ship's officers practicing traditional celestial navigation taking a sunsight by sextant]]
===Ships and similar vessels===
====One day's work in traditional navigation====
In traditional marine navigation, one day's work in navigation is a minimal set of tasks consistent with prudent celestial navigation. The definition and processes vary on military and civilian vessels, and from ship to ship, but the traditional method takes a form resembling:<ref name="mmoh6-18">Turpin and McEwen, 1980:6–18.</ref>
# Maintain a continuous dead reckoning plot.
# Take two or more star observations at morning twilight for a celestial fix (prudent to observe six stars).
# Morning Sun observation. Can be taken on or near [[prime vertical]] for longitude, or at any time for a line of position.
# Determine compass error by azimuth observation of the Sun.
# Computation of the interval to noon, watch time of local apparent noon, and constants for meridian or ex-meridian sights.
# Noontime meridian or ex-meridian observation of the Sun for noon latitude line. Running fix or cross with Venus line for noon fix.
# Noontime determination the day's run and day's set and drift.
# At least one afternoon Sun line, in case the stars are not visible at twilight.
# Determine compass error by azimuth observation of the Sun.
# Take two or more star observations at evening twilight for a celestial fix (prudent to observe six stars).

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. However, increasingly traditional navigation processes have been replaced with technological processes for marine navigation using GNSS and marine radar.

===Land navigation===
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.

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.

Pedestrian navigation is involved in [[orienteering]], [[Land navigation|land navigation (military)]], and [[wayfinding]].

===Underwater navigation===
{{main|Diver navigation|Submarine navigation}}
Submariners, divers, [[Remotely operated underwater vehicle|remotely operated underwater vehicles]] (ROVs) and other underwater craft carry out underwater navigation by a variety of methods and processes including GNSS, radar navigation and sonar/acoustic position fixing.<ref name="l373">{{cite web | last1=Homeier | first1=Lieutenant Matthew G. | last2=Navy | first2=U.S. | title=Navigate by the Stars—From Beneath the Waves | website=U.S. Naval Institute | date=2021-10-01 | url=https://www.usni.org/magazines/proceedings/2021/october/navigate-stars-beneath-waves | access-date=2025-02-24}}</ref><ref name="f657">{{cite book | last1=Christ | first1=Robert D. | last2=Sr. | first2=Robert L. Wernli | title=The ROV Manual | publisher=Butterworth-Heinemann | publication-place=Amsterdam | date=2013-10-30 | isbn=978-0-08-098288-5}}</ref>

===Artificial intelligence===
[[Artificial intelligence]] can be utilised to assist with planning, problem-serving and decision-making processes in navigation.<ref name="e302">{{cite conference | last=Duffany | first=Jeffrey L. | title=2010 2nd International Conference on Software Technology and Engineering | chapter=Artificial intelligence in GPS navigation systems | publisher=IEEE | year=2010 | doi=10.1109/icste.2010.5608862 | page=| isbn=978-1-4244-8667-0 }}</ref><ref name="a073">{{cite book | last1=Jindal | first1=R. | last2=Mittal | first2=S.K. | title=Artificial Intelligence: Application and Real-Time Use | publisher=Codex International Publishers | year=2023 | isbn=978-93-94799-24-0 | url=https://books.google.com/books?id=hKzEEAAAQBAJ&pg=PA45 | access-date=2025-02-24 | page=45}}</ref> This includes using AI in navigation systems such as GNSS as well as in general computing to assist with position fixing and monitoring from one position to another such as in vehicles, planes and cars.<ref name="t787">{{cite journal | last1=Viveiros | first1=Inês | last2=Silva | first2=Hélder | last3=Andrade | first3=Yuri | last4=Pendão | first4=Cristiano | title=Smart GNSS Integrity Monitoring for Road Vehicles: An Overview of AI Methods | journal=IEEE Access | volume=13 | date=2025 | issn=2169-3536 | doi=10.1109/ACCESS.2025.3534659 | doi-access=free | pages=20278–20296| bibcode=2025IEEEA..1320278V }}</ref><ref name="f467">{{cite book | last=Yu | first=K. | title=Positioning and Navigation Using Machine Learning Methods | publisher=Springer Nature Singapore | series=Navigation: Science and Technology | year=2024 | isbn=978-981--976199-9 | url=https://books.google.com/books?id=ovYhEQAAQBAJ&pg=PA32 | access-date=2025-02-24 | page=32}}</ref>