Editing Gyrocompass (section)

{{Short description|Type of non-magnetic compass based on the rotation of the Earth}}
{{About|devices used on ships|the type of gyroscope used to determine aircraft heading|Heading indicator}}
[[File:Kreiselkompass Schnitt Anschütz.jpg|thumb|Cutaway of an Anschütz gyrocompass]]
[[File:Algonquin gyro compass2.jpg|thumb|A gyrocompass repeater]]

A '''gyrocompass''' is a type of non-magnetic [[compass]] which is based on a fast-spinning disc and the rotation of the [[Earth]] (or another planetary body if used elsewhere in the universe) to find geographical [[Direction (geometry)|direction]] automatically. A gyrocompass makes use of one of the seven fundamental ways to determine the heading of a vehicle.<ref name="JournalOfNavigation2016">{{cite journal |last= Gade |first= Kenneth |year= 2016 |title= The Seven Ways to Find Heading |journal= The Journal of Navigation |publisher= Cambridge University Press |volume= 69 |issue= 5 |pages=955–970 |url=http://www.navlab.net/Publications/The_Seven_Ways_to_Find_Heading.pdf |doi= 10.1017/S0373463316000096 |s2cid= 53587934 }}</ref> A [[gyroscope]] is an essential component of a gyrocompass, but they are different devices; a gyrocompass is built to use the effect of [[gyroscopic precession]], which is a distinctive aspect of the general [[gyroscopic effect]].<ref name=an>{{cite book| url=https://books.google.com/books?id=VJ3WCpegQxwC|title=The Anschutz Gyro-Compass and Gyroscope Engineering| pages=7–24|isbn=978-1-929148-12-7|author1=Elliott-Laboratories|date=2003|publisher=Watchmaker |url-status=live|archive-url=https://web.archive.org/web/20170304174125/https://books.google.com/books?id=VJ3WCpegQxwC|archive-date=2017-03-04}}</ref><ref name=l>{{cite magazine|title=The gyroscope pilots ships & planes|magazine=Life|date=Mar 15, 1943|pages=80–83|url=https://books.google.com/books?id=YlEEAAAAMBAJ&pg=PA82|author=Time Inc.|url-status=live|archive-url=https://web.archive.org/web/20170227154326/https://books.google.com/books?id=YlEEAAAAMBAJ&pg=PA82|archive-date=2017-02-27}}</ref>  Gyrocompasses, such as the [[fibre optic gyrocompass]] are widely used to provide a heading for [[navigation]] on [[ship]]s.<ref name="SafeNavWatch">{{cite book |date=2023 |title=Safe Nav Watch |location=Edinburgh |publisher=[[Witherby Publishing Group]] |pages=26–27 |isbn=9781914993466}}</ref><ref>{{Cite book |url=https://books.google.com/books/about/%E9%99%80%E8%9E%BA%E4%BB%AA%E5%8E%9F%E7%90%86%E5%8F%8A%E5%BA%94%E7%94%A8.html?id=K5BrGwAACAAJ |title= |publisher={{ill|Harbin Institute of Technology Press|zh|哈尔滨工业大学出版社}} |year=1985 |editor-last=郭素云 |language=zh-CN |script-title=zh:陀螺仪原理及应用 |trans-title=The Principle and Application of Gyroscopes |chapter= |id={{interlanguage link|National Standard Book Number of China|zh|lt=统一书号 (National Standard Book Number of China)|统一书号}} 15341·26 |accessdate=2025-04-12}}</ref> This is because they have two significant advantages over [[magnetic compass]]es:<ref name=l />
* they find [[true north]] as determined by the axis of the [[Earth's rotation]], which is different from, and navigationally more useful than,  [[Magnetic North Pole#Magnetic north and magnetic declination|''magnetic'' north]], and
* they have a greater degree of accuracy because they are unaffected by [[ferromagnetic]] materials, such as in a ship's [[steel]] [[hull (watercraft)|hull]], which distort the [[magnetic field]].<ref name="SafeNavWatch"/>

Aircraft commonly use gyroscopic instruments (but not a gyrocompass) for navigation and attitude monitoring; for details, see [[flight instruments]] (specifically the [[heading indicator]]) and [[gyroscopic autopilot]].