Editing Global Positioning System (section)

=== Military ===
[[File:Exelis SINCGARS RT-1523G.jpg|thumb|AN/PRC-119F SINCGARS radio, which requires accurate clock time supplied by an external GPS system to enable frequency hopping operation with other radios]] [[File:US Navy 030319-N-4142G-020 Ordnance handlers assemble Joint Direct Attack Munition (JDAM) bombs in the forward mess decks.jpg|thumb|right|Attaching a GPS guidance kit to an [[unguided bomb]], March 2003]]
[[File:XM982 Excalibur inert.jpg|thumb|right|[[M982 Excalibur]] GPS-guided [[artillery shell]]]]
As of 2009, military GPS applications include:
* Navigation: Soldiers use GPS to find objectives, even in the dark or in unfamiliar territory, and to coordinate troop and supply movement. In the United States armed forces, commanders use the ''Commander's Digital Assistant'' and lower ranks use the ''Soldier Digital Assistant''.<ref>{{cite web|last=Sinha|first=Vandana|url=http://gcn.com/articles/2003/07/24/soldiers-take-digital-assistants-to-war.aspx|title=Commanders and Soldiers' GPS-receivers|publisher=Gcn.com|date=July 24, 2003|access-date=October 13, 2009|archive-url=https://web.archive.org/web/20090921064048/http://gcn.com/articles/2003/07/24/soldiers-take-digital-assistants-to-war.aspx|archive-date=September 21, 2009|url-status=live}}</ref>
* Frequency-Hopping Radio Clock Coordination: Military radio systems using [[Frequency-hopping spread spectrum|frequency hopping]] modes, such as [[SINCGARS]] and [[Have Quick|HAVEQUICK]], require all radios within a network to have the same time input to their internal clocks (+/-4 seconds in the case of SINCGARS) to be on the correct frequency at a given time. Military GPS receivers, such as the [[Precision Lightweight GPS Receiver]] (PLGR) and [[Defense Advanced GPS Receiver]] (DAGR), are used by [[radio operator]]s within a radio network to properly input an accurate time to said radios internal clock. More modern military radios have internal GPS receivers that synchronize the internal clock automatically.
* Target tracking: Various military weapons systems use GPS to track potential ground and air targets before flagging them as hostile.{{Citation needed|date=November 2007}} These weapon systems pass target coordinates to [[precision-guided munition]]s to allow them to engage targets accurately. Military aircraft, particularly in [[air-to-ground]] roles, use GPS to find targets.
* Missile and projectile guidance: GPS allows accurate targeting of various military weapons including [[ICBM]]s, [[cruise missile]]s, [[precision-guided munition]]s and [[artillery shell]]s. Embedded GPS receivers able to withstand accelerations of 12,000 ''[[g-force|g]]''<ref name="dote-fy2003-69">{{cite report |section=Excalibur Family of Artillery Projectiles |url=https://www.dote.osd.mil/Portals/97/pub/reports/FY2003/other/2003DOTEAnnualReport.pdf |publisher=[[Director, Operational Test and Evaluation]] |access-date=May 23, 2023 |archive-url=https://web.archive.org/web/20211018153227/https://www.dote.osd.mil/Portals/97/pub/reports/FY2003/other/2003DOTEAnnualReport.pdf |archive-date=October 18, 2021 |year=2003 |url-status=live |page=69 |title=FY2003 Annual Report }}</ref> or about {{cvt|118|km/s2|||}} have been developed for use in {{convert|155|mm|in|sp=us|adj=on}} [[howitzer]] shells.<ref name="dote-fy2010-xm982">{{cite report |section=Excalibur XM982 Precision Engagement Projectiles |url=https://www.dote.osd.mil/Portals/97/pub/reports/FY2010/army/2010excalibur.pdf |publisher=[[Director, Operational Test and Evaluation]] |access-date=May 23, 2023 |archive-url=https://web.archive.org/web/20221115000445/https://www.dote.osd.mil/Portals/97/pub/reports/FY2010/army/2010excalibur.pdf |archive-date=November 15, 2022 |date=December 2010 |url-status=live |pages=65–66 |title=FY2010 Annual Report }}</ref>
* Search and rescue.
* Reconnaissance: Patrol movement can be managed more closely.
* GPS satellites carry a set of nuclear detonation detectors consisting of an optical sensor called a [[bhangmeter]], an X-ray sensor, a dosimeter, and an electromagnetic pulse (EMP) sensor (W-sensor), that form a major portion of the [[United States Nuclear Detonation Detection System]].<ref>Sandia National Laboratory's [http://www.sandia.gov/LabNews/LN03-07-03/LA2003/la03/arms_story.htm Nonproliferation programs and arms control technology] {{Webarchive|url=https://web.archive.org/web/20060928015946/http://www.sandia.gov/LabNews/LN03-07-03/LA2003/la03/arms_story.htm |date=September 28, 2006 }}</ref><ref>{{cite report |title=The GPS Burst Detector W-Sensor |author=McCrady |first=Dennis D. |date=August 1994 |publisher=Sandia National Laboratories |osti=10176800 |osti-access=free}}</ref> General William Shelton has stated that future satellites may drop this feature to save money.<ref>{{cite web |url=http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_01_18_2013_p0-538541.xml |title=US Air Force Eyes Changes To National Security Satellite Programs. |publisher=Aviationweek.com |date=January 18, 2013 |access-date=September 28, 2013 |archive-url=https://web.archive.org/web/20130922073035/http://www.aviationweek.com/Article.aspx?id=%2Farticle-xml%2Fawx_01_18_2013_p0-538541.xml |archive-date=September 22, 2013 |url-status=live }}</ref>
GPS type navigation was first used in war in the [[Gulf War|1991 Persian Gulf War]], before GPS was fully developed in 1995, to assist [[Coalition of the Gulf War|Coalition Forces]] to navigate and perform maneuvers in the war. The war also demonstrated the vulnerability of GPS to being [[radio jamming|jammed]], when Iraqi forces installed jamming devices on likely targets that emitted radio noise, disrupting reception of the weak GPS signal.<ref>{{cite magazine |title = GPS and the World's First "Space War"|url = http://www.scientificamerican.com/article/gps-and-the-world-s-first-space-war/|magazine= Scientific American|access-date = February 8, 2016|first = Larry|last = Greenemeier|archive-url = https://web.archive.org/web/20160208233555/http://www.scientificamerican.com/article/gps-and-the-world-s-first-space-war/|archive-date = February 8, 2016|url-status = live}}</ref>

GPS's vulnerability to jamming is a threat that continues to grow as jamming equipment and experience grows.<ref>{{cite web|url=https://www.militaryaerospace.com/articles/2016/06/gps-jamming-satellite-navigation.html|title=GPS jamming is a growing threat to satellite navigation, positioning, and precision timing|website=www.militaryaerospace.com|date=June 28, 2016 |access-date=March 3, 2019|archive-url=https://web.archive.org/web/20190306044006/https://www.militaryaerospace.com/articles/2016/06/gps-jamming-satellite-navigation.html|archive-date=March 6, 2019|url-status=live}}</ref><ref>{{cite web |url=https://www.nbcnews.com/news/us-news/gps-under-attack-crooks-rogue-workers-wage-electronic-war-n618761 |title=GPS Under Attack as Crooks, Rogue Workers Wage Electronic War |work=NBC News |last=Brunker |first=Mike |date=August 8, 2016 |archive-url=https://web.archive.org/web/20190306051331/https://www.nbcnews.com/news/us-news/gps-under-attack-crooks-rogue-workers-wage-electronic-war-n618761 |archive-date=March 6, 2019 |url-status=live |access-date=December 15, 2021}}</ref> GPS signals have been reported to have been jammed many times over the years for military purposes. Russia seems to have several objectives for this approach, such as intimidating neighbors while undermining confidence in their reliance on American systems, promoting their GLONASS alternative, disrupting Western military exercises, and protecting assets from drones.<ref>{{cite web|url=https://rntfnd.org/2018/04/30/russia-undermining-worlds-confidence-in-gps/|title=Russia Undermining World's Confidence in GPS|date=April 30, 2018|access-date=March 3, 2019|archive-url=https://web.archive.org/web/20190306050610/https://rntfnd.org/2018/04/30/russia-undermining-worlds-confidence-in-gps/|archive-date=March 6, 2019|url-status=live}}</ref> China uses jamming to discourage US surveillance aircraft near the contested [[Spratly Islands]].<ref>{{cite web|url=https://rntfnd.org/2016/09/26/china-jamming-us-forces-gps/|title=China Jamming US Forces' GPS|date=September 26, 2016|access-date=March 3, 2019|archive-url=https://web.archive.org/web/20190306050548/https://rntfnd.org/2016/09/26/china-jamming-us-forces-gps/|archive-date=March 6, 2019|url-status=live}}</ref> [[North Korea]] has mounted several major jamming operations near its border with South Korea and offshore, disrupting flights, shipping and fishing operations.<ref>{{cite web|url=https://www.popularmechanics.com/military/weapons/a20289/north-korea-jamming-gps-signals/|title=North Korea Is Jamming GPS Signals|first=Kyle|last=Mizokami|date=April 5, 2016|website=Popular Mechanics|access-date=March 3, 2019|archive-url=https://web.archive.org/web/20190306043300/https://www.popularmechanics.com/military/weapons/a20289/north-korea-jamming-gps-signals/|archive-date=March 6, 2019|url-status=live}}</ref> Iranian Armed Forces disrupted the civilian airliner plane Flight [[PS752]]'s GPS when it shot down the aircraft.<ref>{{Cite web|date=December 29, 2020|title=Iran Spokesman Confirms Mysterious Disruption Of GPS Signals In Tehran|url=https://iranintl.com/en/iran/iran-spokesman-confirms-mysterious-disruption-gps-signals-tehran|access-date=July 12, 2021|website=Iran International|language=en|archive-date=July 12, 2021|archive-url=https://web.archive.org/web/20210712184125/https://iranintl.com/en/iran/iran-spokesman-confirms-mysterious-disruption-gps-signals-tehran|url-status=live}}</ref><ref>{{Cite web|date=July 12, 2021|title=Evidence shows Iran shot down Ukrainian plane 'intentionally' {{!}} AvaToday|url=https://avatoday.net/node/14295|access-date=July 12, 2021|archive-url=https://web.archive.org/web/20210712184447/https://avatoday.net/node/14295|archive-date=July 12, 2021}}</ref>

In the [[Russo-Ukrainian War]], GPS-guided munitions provided to Ukraine by NATO countries experienced significant failure rates as a result of Russian electronic warfare. Excalibur artillery shells efficiency rate hitting targets dropped from 70% to 6% as Russia adapted its electronic warfare activities.<ref>{{cite news | url=https://www.businessinsider.com/russian-cheap-electronic-warfare-keeps-beating-us-precision-weapons-2024-4 | title=Russian forces have hit on a cheap way to foil US precision weapons in Ukraine | work=[[Business Insider]] |date=April 30, 2024 |first1=Chris |last1=Panella }}</ref>