Editing Global Positioning System (section)

=== Civilian ===
[[File:GPS roof antenna dsc06160.jpg|thumb|right|upright=0.8|This [[antenna (radio)|antenna]] is mounted on the roof of a hut containing a scientific experiment needing precise timing.]]
[[File:GPSTest screenshot (2025).webp|thumb|Screenshot of GPSTest application showing GPS and other GNSS satellites usage in [[South Tangerang]], [[Indonesia]] (2025)]]

Many civilian applications use one or more of GPS's three basic components: absolute location, relative movement, and time transfer.
* [[Amateur radio]]: clock synchronization required for several digital modes such as [[FT8]], FT4 and JS8; also used with [[Automatic Packet Reporting System|APRS]] for position reporting; is often critical during emergency and disaster communications support. 
* [[Atmosphere]]: studying the [[troposphere]] delays (recovery of the water vapor content) and [[ionosphere]] delays (recovery of the number of free electrons).<ref>{{cite journal |last1=Hadas |first1=T. |last2=Krypiak-Gregorczyk |first2=A. |last3=Hernández-Pajares |first3=M. |last4=Kaplon |first4=J. |last5=Paziewski |first5=J. |last6=Wielgosz |first6=P. |last7=Garcia-Rigo |first7=A. |last8=Kazmierski |first8=K. |last9=Sosnica |first9=K. |last10=Kwasniak |first10=D. |last11=Sierny |first11=J. |last12=Bosy |first12=J. |last13=Pucilowski |first13=M. |last14=Szyszko |first14=R. |last15=Portasiak |first15=K. |last16=Olivares-Pulido |first16=G. |last17=Gulyaeva |first17=T. |last18=Orus-Perez |first18=R. |title=Impact and Implementation of Higher-Order Ionospheric Effects on Precise GNSS Applications: Higher-Order Ionospheric Effects in GNSS |journal=Journal of Geophysical Research: Solid Earth |date=November 2017 |volume=122 |issue=11 |pages=9420–9436 |doi=10.1002/2017JB014750|hdl=2117/114538 |s2cid=54069697 |hdl-access=free }}</ref> Recovery of Earth surface displacements due to the atmospheric pressure loading.<ref>{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Thaller |first2=Daniela |last3=Dach |first3=Rolf |last4=Jäggi |first4=Adrian |last5=Beutler |first5=Gerhard |title=Impact of loading displacements on SLR-derived parameters and on the consistency between GNSS and SLR results |journal=Journal of Geodesy |date=August 2013 |volume=87 |issue=8 |pages=751–769 |doi=10.1007/s00190-013-0644-1 |bibcode=2013JGeod..87..751S |s2cid=56017067 |url=https://boris.unibe.ch/45844/8/190_2013_Article_644.pdf |access-date=March 2, 2021 |archive-date=March 15, 2021 |archive-url=https://web.archive.org/web/20210315203121/https://boris.unibe.ch/45844/8/190_2013_Article_644.pdf |url-status=live }}</ref> 
* [[Astronomy]]: both positional and [[clock synchronization]] data is used in [[astrometry]] and [[celestial mechanics]] and precise orbit determination.<ref>{{cite journal |last1=Bury |first1=Grzegorz |last2=Sośnica |first2=Krzysztof |last3=Zajdel |first3=Radosław |title=Multi-GNSS orbit determination using satellite laser ranging |journal=Journal of Geodesy |date=December 2019 |volume=93 |issue=12 |pages=2447–2463 |doi=10.1007/s00190-018-1143-1|bibcode=2019JGeod..93.2447B |doi-access=free }}</ref> GPS is also used in both [[amateur astronomy]] with [[GoTo (telescopes)|small telescopes]] as well as by professional observatories for finding [[extrasolar planet]]s.
* [[Automated vehicle]]: applying precise vehicle location, coupled with [[High-definition map|highly detailed maps]], provides the context needed for cars and trucks to function without a human driver.<ref>{{Cite web |last=JOUBERT |first=NIELS |last2=REID |first2=TYLER |last3=NOBLE |first3=FERGUS |date=December 2020 |title=Developments in Modern GNSS and Its Impact on Autonomous Vehicle Architectures |url=https://www.swiftnav.com/sites/default/files/whitepapers/swift_nav_modern_gnss_autonomous_vehicles.pdf |access-date=12 February 2025 |website=www.swiftnav.com}}</ref>
* [[Cartography]]: both civilian and military cartographers use GPS extensively.
* [[Cellular telephony]]: clock synchronization enables time transfer, which is critical for synchronizing its spreading codes with other base stations to facilitate inter-cell handoff and support hybrid GPS/cellular position detection for [[E911#Wireless enhanced 911|mobile emergency calls]] and other applications. The first [[Mobile GPS navigation|handsets with integrated GPS]] launched in the late 1990s. The U.S. [[Federal Communications Commission]] (FCC) mandated the feature in either the handset or in the towers (for use in triangulation) in 2002 so emergency services could locate 911&nbsp;callers. Third-party software developers later gained access to GPS APIs from [[Nextel]] upon launch, followed by [[Sprint Nextel|Sprint]] in 2006, and [[Verizon]] soon thereafter.
* [[Clock synchronization]]: the accuracy of GPS time signals (±10 ns)<ref>{{cite web|url=http://tf.nist.gov/time/commonviewgps.htm|title=Common View GPS Time Transfer|publisher=nist.gov|access-date=July 23, 2011|archive-url=https://web.archive.org/web/20121028043917/http://tf.nist.gov/time/commonviewgps.htm|archive-date=October 28, 2012}}</ref> is second only to the atomic clocks they are based on, and is used in applications such as [[GPS disciplined oscillator]]s.
* [[Disaster relief]]/[[emergency service]]s: many emergency services depend upon GPS for location and timing capabilities.
* GPS-equipped [[radiosonde]]s and [[dropsonde]]s: measure and calculate the atmospheric pressure, wind speed and direction up to {{cvt|27|km|ft||}} from the Earth's surface.
* [[Radio occultation]] for weather and atmospheric science applications.<ref>{{cite web|url=http://www2.ucar.edu/atmosnews/just-published/12183/using-gps-improve-tropical-cyclone-forecasts|title=Using GPS to improve tropical cyclone forecasts|work=ucar.edu|access-date=May 28, 2015|archive-url=https://web.archive.org/web/20150528222132/http://www2.ucar.edu/atmosnews/just-published/12183/using-gps-improve-tropical-cyclone-forecasts|archive-date=May 28, 2015|url-status=live}}</ref>
* [[Fleet tracking]]: used to identify, locate and maintain contact reports with one or more [[fleet vehicle|fleet]] vehicles in real-time.
* [[Geodesy]]: determination of [[Earth orientation parameters]] including the daily and sub-daily polar motion,<ref>{{cite journal |last1=Zajdel |first1=Radosław |last2=Sośnica |first2=Krzysztof |last3=Bury |first3=Grzegorz |last4=Dach |first4=Rolf |last5=Prange |first5=Lars |last6=Kazmierski |first6=Kamil |title=Sub-daily polar motion from GPS, GLONASS, and Galileo |journal=Journal of Geodesy |date=January 2021 |volume=95 |issue=1 |page=3 |doi=10.1007/s00190-020-01453-w| issn=0949-7714|bibcode=2021JGeod..95....3Z |doi-access=free }}</ref> and length-of-day variabilities,<ref>{{cite journal |last1=Zajdel |first1=Radosław |last2=Sośnica |first2=Krzysztof |last3=Bury |first3=Grzegorz |last4=Dach |first4=Rolf |last5=Prange |first5=Lars |title=System-specific systematic errors in earth rotation parameters derived from GPS, GLONASS, and Galileo |journal=GPS Solutions |date=July 2020 |volume=24 |issue=3 |page=74 |doi=10.1007/s10291-020-00989-w|bibcode=2020GPSS...24...74Z |doi-access=free }}</ref> Earth's center-of-mass – geocenter motion,<ref>{{cite journal |last1=Zajdel |first1=Radosław |last2=Sośnica |first2=Krzysztof |last3=Bury |first3=Grzegorz |title=Geocenter coordinates derived from multi-GNSS: a look into the role of solar radiation pressure modeling |journal=GPS Solutions |date=January 2021 |volume=25 |issue=1 |page=1 |doi=10.1007/s10291-020-01037-3|bibcode=2021GPSS...25....1Z |doi-access=free }}</ref> and low-degree gravity field parameters.<ref>{{cite journal |last1=Glaser |first1=Susanne |last2=Fritsche |first2=Mathias |last3=Sośnica |first3=Krzysztof |last4=Rodríguez-Solano |first4=Carlos Javier |last5=Wang |first5=Kan |last6=Dach |first6=Rolf |last7=Hugentobler |first7=Urs |last8=Rothacher |first8=Markus |last9=Dietrich |first9=Reinhard |title=A consistent combination of GNSS and SLR with minimum constraints |journal=Journal of Geodesy |date=December 2015 |volume=89 |issue=12 |pages=1165–1180 |doi=10.1007/s00190-015-0842-0|bibcode=2015JGeod..89.1165G |s2cid=118344484 |url=https://boris.unibe.ch/71369/ }}</ref>
* [[Geofence|Geofencing]]: [[vehicle tracking system]]s, [[Handheld tracker|person tracking systems]], and [[Tracking collar|pet tracking]] systems use GPS to locate devices that are attached to or carried by a person, vehicle, or pet. The application can provide continuous tracking and send notifications if the target leaves a designated (or "fenced-in") area.<ref name="Rouse">{{Cite encyclopedia|url=http://whatis.techtarget.com/definition/geofencing|title=What is geo-fencing (geofencing)?|language=en-US|date=December 2016|encyclopedia=WhatIs.com|publisher=TechTarget|location=Newton, Massachusetts|access-date=January 26, 2020|last=Rouse|first=Margaret}}</ref>
* [[Geotagging]]: applies location coordinates to digital objects such as photographs (in [[Exif]] data) and other documents for purposes such as creating map overlays with devices like [[Nikon GP-1]].
* [[GPS aircraft tracking]]
* [[GPS for mining]]: the use of RTK GPS has significantly improved several mining operations such as drilling, shoveling, vehicle tracking, and surveying. RTK GPS provides centimeter-level positioning accuracy.<ref>{{Cite book |last=Sickle |first=Jan Van |url=https://www.taylorfrancis.com/books/mono/10.4324/9780203305225/gps-land-surveyors-jan-van-sickle |title=GPS for Land Surveyors |date=October 10, 2011 |publisher=CRC Press |isbn=978-0-429-14911-5 |edition=3 |location=Boca Raton |doi=10.4324/9780203305225}}</ref><ref>{{Cite journal |last1=Wesche |first1=Christine |last2=Eisen |first2=Olaf |last3=Oerter |first3=Hans |last4=Schulte |first4=Daniel |last5=Steinhage |first5=Daniel |date=January 2007 |title=Surface topography and ice flow in the vicinity of the EDML deep-drilling site, Antarctica |url=https://www.cambridge.org/core/journals/journal-of-glaciology/article/surface-topography-and-ice-flow-in-the-vicinity-of-the-edml-deepdrilling-site-antarctica/B796D8428791FCC28ABCF298FAC3EABA |journal=Journal of Glaciology |language=en |volume=53 |issue=182 |pages=442–448 |doi=10.3189/002214307783258512 |bibcode=2007JGlac..53..442W |issn=0022-1430}}</ref>
* [[GPS data mining]]: It is possible to aggregate GPS data from multiple users to understand movement patterns, common trajectories and interesting locations.<ref>{{cite conference |author=Khetarpaul, S. |author2=Chauhan, R. |author3=Gupta, S. K. |author4=Subramaniam, L. V. |author5=Nambiar, U. |title=Mining GPS data to determine interesting locations|year=2011|book-title=Proceedings of the 8th International Workshop on Information Integration on the Web}}</ref> GPS data is today used in transportation and disaster engineering to forecast mobility in normal and evacuation situations (e.g., hurricanes, wildfires, earthquakes).<ref>{{Cite journal |last1=Sivalingam |first1=Prahaladhan |last2=Asirvatham |first2=David |last3=Marjani |first3=Mohsen |last4=Syed Masood |first4=Jafar Ali Ibrahim |last5=Chakravarthy |first5=N. S. Kalyan |last6=Veerisetty |first6=Gopinath |last7=Lestari |first7=Martha Tri |date=April 1, 2024 |title=A review of travel behavioural pattern using GPS dataset: A systematic literature review |journal=Measurement: Sensors |volume=32 |pages=101031 |doi=10.1016/j.measen.2024.101031 |issn=2665-9174|doi-access=free |bibcode=2024MeasS..3201031S }}</ref><ref>{{Cite book |last1=Nakajima |first1=Yuu |last2=Shiina |first2=Hironori |last3=Yamane |first3=Shohei |last4=Ishida |first4=Toru |last5=Yamaki |first5=Hirofumi |chapter=Disaster Evacuation Guide: Using a Massively Multiagent Server and GPS Mobile Phones |date=January 2007 |title=2007 International Symposium on Applications and the Internet |chapter-url=https://ieeexplore.ieee.org/document/4090038 |pages=2 |doi=10.1109/SAINT.2007.13}}</ref><ref>{{Cite journal |last1=Zhao |first1=Xilei |last2=Xu |first2=Yiming |last3=Lovreglio |first3=Ruggiero |last4=Kuligowski |first4=Erica |last5=Nilsson |first5=Daniel |last6=Cova |first6=Thomas J. |last7=Wu |first7=Alex |last8=Yan |first8=Xiang |date=June 1, 2022 |title=Estimating wildfire evacuation decision and departure timing using large-scale GPS data |url=https://www.sciencedirect.com/science/article/pii/S136192092200102X |journal=Transportation Research Part D: Transport and Environment |volume=107 |pages=103277 |doi=10.1016/j.trd.2022.103277 |issn=1361-9209|arxiv=2109.07745 |bibcode=2022TRPD..10703277Z }}</ref><ref>{{Cite journal |last1=Yang |first1=Zhuo |last2=Franz |first2=Mark L. |last3=Zhu |first3=Shanjiang |last4=Mahmoudi |first4=Jina |last5=Nasri |first5=Arefeh |last6=Zhang |first6=Lei |date=January 1, 2018 |title=Analysis of Washington, DC taxi demand using GPS and land-use data |url=https://www.sciencedirect.com/science/article/pii/S0966692317301102 |journal=Journal of Transport Geography |volume=66 |pages=35–44 |doi=10.1016/j.jtrangeo.2017.10.021 |bibcode=2018JTGeo..66...35Y |issn=0966-6923|url-access=subscription }}</ref>
* [[GPS tour]]s: location determines what content to display; for instance, information about an approaching point of interest.
* [[Mental health]]: tracking mental health functioning and sociability.<ref>{{Cite journal |last1=Braund |first1=Taylor A. |last2=Zin |first2=May The |last3=Boonstra |first3=Tjeerd W. |last4=Wong |first4=Quincy J. J. |last5=Larsen |first5=Mark E. |last6=Christensen |first6=Helen |last7=Tillman |first7=Gabriel |last8=O'Dea |first8=Bridianne |date=May 4, 2022 |title=Smartphone Sensor Data for Identifying and Monitoring Symptoms of Mood Disorders: A Longitudinal Observational Study |journal=JMIR Mental Health |language=EN |volume=9 |issue=5 |pages=e35549 |doi=10.2196/35549 | pmid=35507385|pmc=9118091 |doi-access=free }}</ref>
* [[Navigation]]: navigators value digitally precise velocity and orientation measurements, as well as precise positions in real-time with a support of orbit and clock corrections.<ref>{{cite journal |last1=Kazmierski |first1=Kamil |last2=Zajdel |first2=Radoslaw |last3=Sośnica |first3=Krzysztof |title=Evolution of orbit and clock quality for real-time multi-GNSS solutions |journal=GPS Solutions |date=October 2020 |volume=24 |issue=4 |page=111 |doi=10.1007/s10291-020-01026-6|bibcode=2020GPSS...24..111K |doi-access=free }}</ref>
* [[Orbit]] determination of low-orbiting satellites with GPS receiver installed on board, such as [[GOCE]],<ref>{{cite journal |last1=Strugarek |first1=Dariusz |last2=Sośnica |first2=Krzysztof |last3=Jäggi |first3=Adrian |title=Characteristics of GOCE orbits based on Satellite Laser Ranging |journal=Advances in Space Research |date=January 2019 |volume=63 |issue=1 |pages=417–431 |doi=10.1016/j.asr.2018.08.033|bibcode=2019AdSpR..63..417S |s2cid=125791718 }}</ref> [[GRACE and GRACE-FO|GRACE]], [[Jason-1]], [[Jason-2]], [[TerraSAR-X]], [[TanDEM-X]], [[CHAMP (satellite)|CHAMP]], [[Sentinel-3]],<ref>{{cite journal |last1=Strugarek |first1=Dariusz |last2=Sośnica |first2=Krzysztof |last3=Arnold |first3=Daniel |last4=Jäggi |first4=Adrian |last5=Zajdel |first5=Radosław |last6=Bury |first6=Grzegorz |last7=Drożdżewski |first7=Mateusz |title=Determination of Global Geodetic Parameters Using Satellite Laser Ranging Measurements to Sentinel-3 Satellites |journal=Remote Sensing |date=September 30, 2019 |volume=11 |issue=19 |page=2282 |doi=10.3390/rs11192282|bibcode=2019RemS...11.2282S |doi-access=free }}</ref> and some cubesats, e.g., [[CubETH]].
* [[Phasor measurement unit|Phasor measurements]]: GPS enables highly accurate timestamping of power system measurements, making it possible to compute [[Phasor measurement unit|phasors]].
* [[Recreation]]: for example, [[Geocaching]], [[Geodashing]], [[GPS drawing]], [[waymarking]], and other kinds of [[Location-based game|location based mobile games]] such as ''[[Pokémon Go]]''.
* [[Reference frames]]: realization and densification of the terrestrial reference frames<ref>{{cite journal |last1=Zajdel |first1=R. |last2=Sośnica |first2=K. |last3=Dach |first3=R. |last4=Bury |first4=G. |last5=Prange |first5=L. |last6=Jäggi |first6=A. |title=Network Effects and Handling of the Geocenter Motion in Multi-GNSS Processing |journal=Journal of Geophysical Research: Solid Earth |date=June 2019 |volume=124 |issue=6 |pages=5970–5989 |doi=10.1029/2019JB017443|bibcode=2019JGRB..124.5970Z |doi-access=free }}</ref> in the framework of Global Geodetic Observing System. Co-location in space between [[Satellite laser ranging]]<ref>{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Thaller |first2=Daniela |last3=Dach |first3=Rolf |last4=Steigenberger |first4=Peter |last5=Beutler |first5=Gerhard |last6=Arnold |first6=Daniel |last7=Jäggi |first7=Adrian |title=Satellite laser ranging to GPS and GLONASS |journal=Journal of Geodesy |date=July 2015 |volume=89 |issue=7 |pages=725–743 |doi=10.1007/s00190-015-0810-8|bibcode=2015JGeod..89..725S |doi-access=free }}</ref> and microwave observations<ref>{{cite journal |last1=Bury |first1=Grzegorz |last2=Sośnica |first2=Krzysztof |last3=Zajdel |first3=Radosław |last4=Strugarek |first4=Dariusz |last5=Hugentobler |first5=Urs |title=Determination of precise Galileo orbits using combined GNSS and SLR observations |journal=GPS Solutions |date=January 2021 |volume=25 |issue=1 |page=11 |doi=10.1007/s10291-020-01045-3|bibcode=2021GPSS...25...11B |doi-access=free }}</ref> for deriving global geodetic parameters.<ref>{{cite journal |last1=Sośnica |first1=K. |last2=Bury |first2=G. |last3=Zajdel |first3=R. |title=Contribution of Multi-GNSS Constellation to SLR-Derived Terrestrial Reference Frame |journal=Geophysical Research Letters |date=March 16, 2018 |volume=45 |issue=5 |pages=2339–2348 |doi=10.1002/2017GL076850|bibcode=2018GeoRL..45.2339S |s2cid=134160047 }}</ref><ref>{{cite journal |last1=Sośnica |first1=K. |last2=Bury |first2=G. |last3=Zajdel |first3=R. |last4=Strugarek |first4=D. |last5=Drożdżewski |first5=M. |last6=Kazmierski |first6=K. |title=Estimating global geodetic parameters using SLR observations to Galileo, GLONASS, BeiDou, GPS, and QZSS |journal=Earth, Planets and Space |date=December 2019 |volume=71 |issue=1 |page=20 |doi=10.1186/s40623-019-1000-3|bibcode=2019EP&S...71...20S |doi-access=free }}</ref>
* [[Robotics]]: self-navigating, autonomous robots using GPS sensors,<ref>{{Cite web|title=GPS Helps Robots Get the Job Done|url=https://www.asme.org/topics-resources/content/gps-helps-robots-get-job-done|access-date=August 3, 2021|website=www.asme.org|language=en|archive-date=August 3, 2021|archive-url=https://web.archive.org/web/20210803230646/https://www.asme.org/topics-resources/content/gps-helps-robots-get-job-done|url-status=live}}</ref> which calculate latitude, longitude, time, speed, and heading.
* Sport: used in football and rugby for the control and analysis of the training load.<ref name="LiveViewGPS 2012-09-06">{{cite web |url=http://www.liveviewgps.com/blog/gps-tracking-technology-australian-football/ |title=The Use of GPS Tracking Technology in Australian Football |date=September 6, 2012 |access-date=September 25, 2016 |archive-url=https://web.archive.org/web/20160927063511/http://www.liveviewgps.com/blog/gps-tracking-technology-australian-football/ |archive-date=September 27, 2016 |url-status=live }}</ref>
* [[Surveying]]: surveyors use absolute locations to make maps and determine property boundaries.
* [[Tectonics]]: GPS enables direct fault motion measurement of [[earthquakes]]. Between earthquakes GPS can be used to measure [[Crust (geology)|crustal]] motion and deformation<ref>{{cite web|url=http://www.geodesy.cwu.edu/realtime/|title=The Pacific Northwest Geodetic Array|work=cwu.edu|access-date=October 10, 2014|archive-url=https://web.archive.org/web/20140911110131/http://www.geodesy.cwu.edu/realtime/|archive-date=September 11, 2014|url-status=live}}</ref> to estimate seismic strain buildup for creating [[seismic hazard]] maps.
* [[Telematics]]: GPS technology integrated with computers and mobile communications technology in [[automotive navigation system]]s.
<!--* GPS enables researchers to explore Earth's environment including the atmosphere, ionosphere and gravity field. how???-->
<!--

Compared to a few years ago, GPS technology for handsets has matured considerably, offering much better performance in terms of sensitivity, power consumption, size and price. What is more, the OMA SUPL A-GPS standard has enabled lower cost deployment of A-GPS services that ensure a better and more consistent user experience necessary for the mass consumer market. The SUPL A-GPS standard allows network operators or handset manufacturers to deploy assistance services that reduce the time to first fix, lowers the power consumption, and enhances the sensitivity of the GPS receiver. The SUPL standard uses User Plane communication channels such as SMS and GPRS to transport the aiding data, as opposed to the control plane channels in networks, thereby reducing the load on the networks, as well as complexity and cost of service deployment. New business models have also become possible, ranging from hosted services for operators that want to minimize capital investments, to services deployed by handset vendors for end-users that cannot get similar services from their network operator yet.

The major handset software platforms and operating systems are evolving, ensuring easier integration of GPS functionality for handset manufacturers and more powerful features for application developers. Along with the improving performance of handsets, in terms of screen size, processing power and memory size, current handsets thus provide much better platforms for location-enabled applications and services than before.

The GPS value-chain was reshaped considerably in 2007 as several specialist GPS technology developers were acquired by wireless chipset vendors. These transactions are likely to enhance the possibilities to meet handset manufacturers' demand for integrated connectivity solutions that include GPS at ever lower price points to enable true mass market deployment.

Sales of GPS-enabled GSM/WCDMA handsets grew to about 24.5&nbsp;million units in 2007 according to independent analyst firm Berg Insight. Although the number is very small in comparison with the 150 million GPS-enabled CDMA handsets sold, the number is growing rapidly. Berg Insight estimates that shipments of GPS-enabled GSM/WCDMA handsets will grow to 370&nbsp;million units in 2012, the equivalent of more than 26 percent of all GSM/WCDMA handsets sold that year. Including CDMA handsets, GPS-enabled handsets sales are estimated to reach about 560&nbsp;million, or 35&nbsp;percent of total handset shipments in 2012.

-->

==== Restrictions on civilian use ====
The U.S. government controls the export of some civilian receivers. All GPS receivers capable of functioning above {{cvt|60,000|ft|km||abbr=in|sp=us}} above sea level and {{cvt|1000|knot|m/s km/h mph|sigfig=1|abbr=in|sp=us}}, or designed or modified for use with unmanned missiles and aircraft, are classified as [[United States Munitions List|munitions]] (weapons)—which means they require [[United States Department of State|State Department]] export licenses.<ref>Arms Control Association.[http://www.armscontrol.org/documents/mtcr Missile Technology Control Regime] {{webarchive|url=https://web.archive.org/web/20080916123933/http://www.armscontrol.org/documents/mtcr |date=September 16, 2008 }}. Retrieved May 17, 2006.</ref> This rule applies even to otherwise purely civilian units that only receive the L1 frequency and the C/A (Coarse<!-- "Coarse" is correct, as in "not finely detailed"-->/Acquisition) code.

Disabling operation above these limits exempts the receiver from classification as a munition. Vendor interpretations differ. The rule refers to operation at both the target altitude and speed, but some receivers stop operating even when stationary. This has caused problems with some amateur radio balloon launches that regularly reach {{convert|30|km|ft|sigfig=1|abbr=in|sp=us}}. These limits only apply to units or components exported from the United States. A growing trade in various components exists, including GPS units from other countries. These are expressly sold as [[International Traffic in Arms Regulations|ITAR]]-free.