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Array ( [0] => {{short description|Chinese satellite navigation system}} [1] => {{redirect|Beidou}} [2] => {{Expand language|topic=|langcode=zh|date=October 2023}} [3] => {{Use British English|date=June 2020}} [4] => {{Use dmy dates|date=June 2020}} [5] => {{Infobox navigation satellite system [6] => | name = BeiDou Navigation Satellite System [7] => | image = Beidou logo.png [8] => | image_size = 200 [9] => | image_caption = Logo of BeiDou [10] => | country = [[China]] [11] => | type = Military, commercial [12] => | status = Operational [13] => | operator = [[China National Space Administration|CNSA]] [14] => | coverage = Global [15] => | precision = 3.6 m (global, public)
2.6 m (Asia Pacific, public)
10 cm (encrypted){{cite web|url=http://www.spacesafetymagazine.com/space-on-earth/international-relations/department-defense-reports-chinas-space-capabilities/|title=US Department of Defense Reports on China's Space Capabilities|first1=Merryl Azriel on|last1=May 27|first2=2013 in|last2=Space|first3=International|last3=Relations |date=27 May 2013|website=Space Safety Magazine|access-date=1 August 2015|archive-url=https://web.archive.org/web/20160907133801/http://www.spacesafetymagazine.com/space-on-earth/international-relations/department-defense-reports-chinas-space-capabilities/|archive-date=7 September 2016|url-status=live}} [16] => | satellites_nominal = 30 [17] => | satellites_current = 35 [18] => | first_launch = 31 October 2000 [19] => | last_launch = 23 June 2020{{cite news|url=https://business.financialpost.com/pmn/business-pmn/china-puts-final-satellite-for-beidou-network-into-orbit-state-media|title=China puts final satellite for Beidou network into orbit -state media|newspaper=Financialpost|publisher=Financial Post|access-date=22 June 2020|archive-date=25 June 2020|archive-url=https://web.archive.org/web/20200625041151/https://business.financialpost.com/pmn/business-pmn/china-puts-final-satellite-for-beidou-network-into-orbit-state-media|url-status=live}} [20] => | launch_total = 59{{cite web|title=北斗卫星发射一览表|url=http://www.beidou.gov.cn/xt/fsgl/|website=北斗卫星导航系统|access-date=19 November 2018|archive-url=https://web.archive.org/web/20181119132959/http://www.beidou.gov.cn/xt/fsgl/|archive-date=19 November 2018|url-status=live}} [21] => | regime = [[Geostationary orbit|GEO]], [[Inclined orbit#Geosynchronous orbits|IGSO]], [[Medium Earth orbit|MEO]] [22] => | cost = [23] => | website = {{Official URL}} [24] => | orbit_period = {{Fraction|7|13}} [[Sidereal day|sd]] or 12 hours and 53 minutes [25] => | revisit_period = 7 sidereal days [26] => }} [27] => {{Geodesy}} [28] => [29] => The '''BeiDou Navigation Satellite System''' ('''BDS'''; {{zh|c=北斗卫星导航系统|p=běidǒu wèixīng dǎoháng xìtǒng}}) is a [[satellite navigation|satellite-based radio navigation system]] owned and operated by the [[China National Space Administration]].{{Cite web |title=北斗导航系统 |url=https://www.cnsa.gov.cn/n6758824/n6759009/n6759043/index.html |access-date=2023-11-04 |website=www.cnsa.gov.cn |archive-date=4 November 2023 |archive-url=https://web.archive.org/web/20231104232102/https://www.cnsa.gov.cn/n6758824/n6759009/n6759043/index.html |url-status=live }} It is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a BDS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more BDS satellites.{{Cite journal |last1=Xiong |first1=Jing |last2=Han |first2=Fei |date=2020-01-01 |title=Positioning performance analysis on combined GPS/BDS precise point positioning |journal=Geodesy and Geodynamics |volume=11 |issue=1 |pages=78–83 |doi=10.1016/j.geog.2019.11.001 |bibcode=2020G&G....11...78X |s2cid=214436136 |issn=1674-9847 |doi-access=free }} It does not require the user to transmit any data, and operates independently of any telephonic or Internet reception, though these technologies can enhance the usefulness of the BDS positioning information.{{Cite web |title=The Application Service Architecture of BeiDou Navigation Satellite System |url=http://www.beidou.gov.cn/xt/gfxz/201912/P020191227337275341705.pdf |website=China Satellite Navigation Office}} [30] => [31] => The current service, '''BeiDou-3''' (third-generation BeiDou), provides full global coverage for timing and navigation, along with Russia's [[GLONASS]], the European [[Galileo (satellite navigation)|Galileo]], and the US's [[Global Positioning System|GPS]].{{Cite web |title=BDS - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/bds |access-date=2023-11-04 |website=www.sciencedirect.com |archive-date=4 November 2023 |archive-url=https://web.archive.org/web/20231104232100/https://www.sciencedirect.com/topics/earth-and-planetary-sciences/bds |url-status=live }} [32] => It consists of satellites in three different orbits, including 24 satellites in medium-circle orbits (covering the world), 3 satellites in inclined geosynchronous orbits (covering the Asia–Pacific region), and 3 satellites in geostationary orbits (covering China). The BeiDou-3 system was fully operational in July 2020.{{Cite web |date=31 March 2015 |title=中国北斗导航卫星再次进入密集发射期 |url=http://www.chinanews.com/gn/2015/03-31/7170977.shtml |url-status=live |archive-url=https://web.archive.org/web/20170711200559/http://www.chinanews.com/gn/2015/03-31/7170977.shtml |archive-date=11 July 2017 |access-date=16 June 2017 |publisher=中国新闻社}}{{Cite web |last1=PTI |first1=K. J. M. Varma |date=27 December 2018 |title=China's BeiDou navigation satellite, rival to US GPS, starts global services |url=https://www.livemint.com/Technology/9rkTgLBMCHVottY3rP636J/Chinas-BeiDou-navigation-satellite-rival-to-US-GPS-starts.html |url-status=live |archive-url=https://web.archive.org/web/20181227230231/https://www.livemint.com/Technology/9rkTgLBMCHVottY3rP636J/Chinas-BeiDou-navigation-satellite-rival-to-US-GPS-starts.html |archive-date=27 December 2018 |access-date=27 December 2018 |website=livemint.com}}{{Cite web |title=The BDS-3 Preliminary System Is Completed to Provide Global Services |url=http://en.beidou.gov.cn/WHATSNEWS/201812/t20181227_16837.html |url-status=live |archive-url=https://web.archive.org/web/20181227230434/http://en.beidou.gov.cn/WHATSNEWS/201812/t20181227_16837.html |archive-date=27 December 2018 |access-date=27 December 2018 |website=news.dwnews.com}}{{cite news |date=23 June 2020 |title=China puts final satellite for Beidou network into orbit – state media |language=en |work=Reuters |url=https://uk.reuters.com/article/us-space-exploration-china-satellite/china-puts-final-satellite-for-beidou-network-into-orbit-state-media-idUKKBN23U08P |access-date=23 June 2020 |archive-date=28 October 2020 |archive-url=https://web.archive.org/web/20201028212332/https://uk.reuters.com/article/us-space-exploration-china-satellite/china-puts-final-satellite-for-beidou-network-into-orbit-state-media-idUKKBN23U08P |url-status=live }}{{Cite web |title="数"说北斗丨北斗究竟发了多少颗卫星？_新闻_央视网(cctv.com) |url=http://m.news.cctv.com/2020/06/15/ARTIXUxpLLsgU7ip7pJ2NbqP200615.shtml |access-date=2023-11-04 |website=m.news.cctv.com |archive-date=4 November 2023 |archive-url=https://web.archive.org/web/20231104232100/http://m.news.cctv.com/2020/06/15/ARTIXUxpLLsgU7ip7pJ2NbqP200615.shtml |url-status=live }} In 2016, BeiDou-3 reached millimeter-level accuracy with post-processing.{{cite news |date=6 December 2016 |title=Directions 2017: BeiDou's road to global service |work=GPS World |url=http://gpsworld.com/directions-2017-beidous-road-to-global-service/ |url-status=live |access-date=8 May 2017 |archive-url=https://web.archive.org/web/20170527131959/http://gpsworld.com/directions-2017-beidous-road-to-global-service/ |archive-date=27 May 2017}} [33] => [34] => Predecessors included '''BeiDou-1''' (first-generation BeiDou), consisting of three satellites in a [[regional satellite navigation system]]. Since 2000, the system has mainly provided navigation services within China. In December 2012, as the design life of BeiDou-1 expired, it stopped operating.{{Cite web |title=20年磨一剑——北斗导航系统的发展历程--中国数字科技馆 |url=https://www.cdstm.cn/frontier/hthk/202103/t20210330_1045094.html |access-date=2023-11-04 |website=China Digital Science and Technology Museum |archive-date=22 October 2022 |archive-url=https://web.archive.org/web/20221022181318/https://www.cdstm.cn/frontier/hthk/202103/t20210330_1045094.html |url-status=live }} [35] => The '''BeiDou-2''' (second-generation BeiDou) system was also a regional satellite navigation system containing 16 satellites, including 6 geostationary satellites, 6 inclined geosynchronous orbit satellites, and 4 medium earth orbit satellites. In November 2012, BeiDou-2 began to provide users with regional positioning services in the [[Asia–Pacific|Asia–Pacific region]].{{cite news |date=27 December 2011 |title=China GPS rival Beidou starts offering navigation data |publisher=BBC |url=https://www.bbc.co.uk/news/technology-16337648 |url-status=live |access-date=20 June 2018 |archive-url=https://web.archive.org/web/20120203001904/http://www.bbc.co.uk/news/technology-16337648 |archive-date=3 February 2012}}{{cite web |date=27 December 2012 |title=China's Beidou GPS-substitute opens to public in Asia |url=https://www.bbc.co.uk/news/technology-20852150 |url-status=live |archive-url=https://web.archive.org/web/20121227182347/http://www.bbc.co.uk/news/technology-20852150 |archive-date=27 December 2012 |access-date=27 December 2012 |publisher=BBC}} Within the region, BeiDou is more accurate than GPS.{{Cite book |last=Parzyan |first=Anahit |url= |title=China and Eurasian Powers in a Multipolar World Order 2.0: Security, Diplomacy, Economy and Cyberspace |date=2023 |publisher=[[Routledge]] |others=Mher Sahakyan |isbn=978-1-003-35258-7 |edition= |location=New York |pages= |chapter=China's Digital Silk Road: Empowering Capabilities for Digital Leadership in Eurasia |oclc=1353290533}}{{Rp|pages=179}} [36] => [37] => In 2015, fifteen years after the satellite system was launched, it was generating a turnover of $31.5 billion per annum for major companies such as [[China Aerospace Science and Industry Corporation]], [[AutoNavi]], and [[Norinco]].{{cite web|url=http://www.chinadaily.com.cn/bizchina/tech/2015-11/16/content_22464083.htm |title=Sky's the limit for Beidou's clients[1]- Chinadaily.com.cn|website=chinadaily.com.cn|access-date=18 November 2015|archive-url=https://web.archive.org/web/20170301051733/http://www.chinadaily.com.cn/bizchina/tech/2015-11/16/content_22464083.htm|archive-date=1 March 2017|url-status=live}} The industry has grown an average of over 20% in value annually to reach $64 billion in 2020.{{Cite web |date=2021-05-27 |title=China's answer to GPS poised to create US$156 billion industry |url=https://www.scmp.com/tech/tech-war/article/3135055/us-china-tech-war-chinas-gps-rival-beidou-poised-support-industry |access-date=2021-10-26 |website=[[South China Morning Post]] |language=en |archive-date=26 October 2021 |archive-url=https://web.archive.org/web/20211026072348/https://www.scmp.com/tech/tech-war/article/3135055/us-china-tech-war-chinas-gps-rival-beidou-poised-support-industry |url-status=live }}{{Cite news|date=2021-05-26|title=China's Beidou navigation system to serve $156 billion home market by 2025|language=en|work=Reuters|url=https://www.reuters.com/article/ctech-us-space-exploration-china-beidou-idCAKCN2D70FR-OCATC|access-date=2021-10-26|archive-date=26 October 2021|archive-url=https://web.archive.org/web/20211026072348/https://www.reuters.com/article/ctech-us-space-exploration-china-beidou-idCAKCN2D70FR-OCATC|url-status=live}} [38] => [39] => == Nomenclature == [40] => The official English name of the system is ''BeiDou Navigation Satellite System''.{{cite web|url=http://www.beidou.gov.cn/2013/03/29/20130329622a1d8c79ee4e5d849867358c1a97bf.html|title=English Name of BeiDou|access-date=31 May 2015|archive-url=https://web.archive.org/web/20151018135107/http://www.beidou.gov.cn/2013/03/29/20130329622a1d8c79ee4e5d849867358c1a97bf.html|archive-date=18 October 2015 |url-status=live}} It is named after the [[Big Dipper]] [[asterism (astronomy)|asterism]], which is known in Chinese as {{Lang-zh|c=|s=|t=|p=Běidǒu|labels=no}} ({{zh|北斗}}). The name literally means "Northern Dipper", the name given by ancient Chinese astronomers to the seven brightest stars of the [[Ursa Major constellation]].{{cite web|first1=William|last1=Atkins |url=http://www.itwire.com/science-news/space/9201-chinese-BeiDou-navigation-satellite-launched-from-long-march-3a-rocket|title=Chinese BeiDou navigation satellite launched from Long March 3A rocket|publisher=[[iTWire.com]]|date=5 February 2007|access-date=19 May 2010|archive-url=https://web.archive.org/web/20121204014912/http://www.itwire.com/science-news/space/9201-chinese-beidou-navigation-satellite-launched-from-long-march-3a-rocket|archive-date=4 December 2012|url-status=live}} Historically, this set of stars was used in navigation to locate the [[Polaris|North Star]]. As such, the name BeiDou also serves as a metaphor for the purpose of the satellite navigation system.{{citation needed|date=June 2020}} [41] => [42] => == History == [43] => === Conception and initial development === [44] => The original idea of a Chinese satellite navigation system was conceived by [[Chen Fangyun]] and his colleagues in the 1980s.{{cite web|url=http://focus.news.163.com/10/1231/09/6P7JHOMM00011SM9.html|title=̽北斗记 ——探秘中国北斗卫星导航定位系统|website=focus.news.163.com|access-date=3 October 2011|archive-url=https://web.archive.org/web/20150610200429/http://focus.news.163.com/10/1231/09/6P7JHOMM00011SM9.html|archive-date=10 June 2015|url-status=dead}} The [[Gulf War]] in 1991 showcased how the GPS gave the US complete advantage on the battlefield and how satellite navigation systems can be used to conduct "space warfare".{{cite web|title=GPS and the World's First "Space War"|url=https://www.scientificamerican.com/article/gps-and-the-world-s-first-space-war/|publisher=Scientific American|access-date=10 February 2023|archive-date=31 January 2023|archive-url=https://web.archive.org/web/20230131012833/https://www.scientificamerican.com/article/gps-and-the-world-s-first-space-war/|url-status=live}} In 1993, China realised the risk of denied access to GPS during the [[Yinhe incident]] and including an alleged case in 1996 during the [[Third Taiwan Strait Crisis]], gave impetus to the creation of its own indigenous satellite navigation system which officially began in 1994.{{Cite web|url=https://www.scmp.com/article/698161/unforgettable-humiliation-led-development-gps-equivalent|title='Unforgettable humiliation' led to development of GPS equivalent|date=12 November 2009|access-date=27 August 2020|archive-date=7 August 2020|archive-url=https://web.archive.org/web/20200807053440/https://www.scmp.com/article/698161/unforgettable-humiliation-led-development-gps-equivalent|url-status=live}} [45] => [46] => According to the [[China National Space Administration]], in 2010, the development of the system would be carried out in three steps:{{cite web [47] => |url=http://www.BeiDou.gov.cn/2010/05/19/20100519101180c595f14a6d9938a42a2d796b56.html|title=The construction of BeiDou navigation system steps into important stage, "Three Steps" development guideline clear and certain|date=19 May 2010|publisher=China National Space Administration|access-date=19 May 2010|language=zh|archive-url=https://web.archive.org/web/20120127042918/http://www.beidou.gov.cn/2010/05/19/20100519101180c595f14a6d9938a42a2d796b56.html|archive-date=27 January 2012|url-status=dead}} [48] => [49] => # 2000–2003: experimental BeiDou navigation system consisting of three satellites [50] => # By 2012: regional BeiDou navigation system covering China and neighboring regions [51] => # By 2020: global BeiDou navigation system [52] => [53] => The first satellite, ''BeiDou-1A'', was launched on 30 October 2000, followed by ''BeiDou-1B'' on 20 December 2000. The third satellite, ''BeiDou-1C'' (a backup satellite), was put into orbit on 25 May 2003.{{cite web|url=http://www.cnsa.gov.cn/n615708/n620172/n677078/n751578/62676.html|title=Comparable with American and Russian in terms of performance, BeiDou-1 navigates for China|date =30 May 2003|publisher=China National Space Administration|access-date=19 May 2010|language=zh|url-status=dead |archive-url=https://web.archive.org/web/20120226131351/http://www.cnsa.gov.cn/n615708/n620172/n677078/n751578/62676.html|archive-date=26 February 2012}}{{cite web|first1=John|last1=Pike |url=http://www.globalsecurity.org/space/world/china/BeiDou.htm|title=BeiDou (Big Dipper)|work=Space|publisher=GlobalSecurity.org|access-date=9 November 2006 |archive-url=https://web.archive.org/web/20061128170852/http://www.globalsecurity.org/space/world/china/beidou.htm|archive-date=28 November 2006|url-status=dead}} The successful launch of ''BeiDou-1C'' also meant the establishment of the BeiDou-1 navigation system. [54] => [55] => On 2 November 2006, China announced that from 2008 BeiDou would offer an open service with an accuracy of 10 metres, timing of 0.2 microseconds, and speed of 0.2 metres/second.{{cite news|first1=Paul|last1=Marks|title=China's satellite navigation plans threaten Galileo|work=[[New Scientist]]|url=https://www.newscientist.com/article/dn10472-chinas-satellite-navigation-plans-threaten-galileo.html|date=8 November 2006|access-date=9 November 2006|archive-url=https://web.archive.org/web/20150424180759/http://www.newscientist.com/article/dn10472-chinas-satellite-navigation-plans-threaten-galileo.html |archive-date=24 April 2015|url-status=live}} [56] => [57] => In February 2007, the fourth and last satellite of the BeiDou-1 system, ''BeiDou-1D'' (sometimes called ''BeiDou-2A'', serving as a backup satellite), was launched.{{cite news|title=China puts new navigation satellite into orbit|publisher=Gov.cn|url=http://english.gov.cn/2007-02/03/content_516638.htm|date=3 February 2007|access-date=20 May 2010|url-status=dead |archive-url=https://web.archive.org/web/20120202150518/http://english.gov.cn/2007-02/03/content_516638.htm|archive-date=2 February 2012}} It was reported that the satellite had suffered from a control system malfunction but was then fully restored.{{cite web|url=http://news.sohu.com/20070418/n249522961.shtml|title=60-day works in space – Story of reparation of the BeiDou satellite |publisher=[[Sohu]]|date=18 April 2007|access-date=23 May 2010|language=zh|archive-url=https://web.archive.org/web/20141208055654/http://news.sohu.com/20070418/n249522961.shtml|archive-date=8 December 2014|url-status=live}} [58] => [59] => In April 2007, the first satellite of BeiDou-2, namely ''Compass-M1'' (to validate frequencies for the BeiDou-2 constellation) was successfully put into its working orbit. The second BeiDou-2 constellation satellite ''Compass-G2'' was launched on 15 April 2009.{{cite web|url=http://www.asmmag.com/news/compass-due-next-year|title=Compass due Next Year|date=4 May 2009|work=Magazine article |publisher=Asian Surveying and Mapping|access-date=5 May 2009|archive-url=https://web.archive.org/web/20090519192644/http://www.asmmag.com/news/compass-due-next-year|archive-date=19 May 2009|url-status=dead}} [60] => [61] => On 15 January 2010, the official website of the BeiDou Navigation Satellite System went online,{{cite web|url=http://news.sohu.com/20100117/n269631862.shtml|title=China successfully launched the third BeiDou satellite|publisher=Sohu|date=17 January 2010|access-date=19 May 2010|language=zh|archive-url=https://web.archive.org/web/20120305093416/http://news.sohu.com/20100117/n269631862.shtml |archive-date=5 March 2012|url-status=live}} and the system's third satellite (''Compass-G1'') was carried into its orbit by a [[Long March 3C]] rocket on 17 January 2010. [62] => [63] => On 2 June 2010, the fourth satellite was launched successfully into orbit.{{cite web|url=http://www.spaceflightnow.com/news/n1006/02longmarch/|title=China sends Beidou navigation satellite to orbit|date=2 June 2010|publisher=Spaceflight Now|access-date=4 June 2010|archive-url=https://web.archive.org/web/20100605031349/http://www.spaceflightnow.com/news/n1006/02longmarch/|archive-date=5 June 2010|url-status=live}} [64] => [65] => The fifth orbiter was launched into space from [[Xichang Satellite Launch Center]] by an [[Long March 3|LM-3I]] carrier rocket on 1 August 2010.{{cite news |url=http://news.xinhuanet.com/english2010/china/2010-08/01/c_13424634.htm|title=China successfully launches fifth satellite for its own global navigation network|publisher=[[Xinhua]]|date=1 August 2010|access-date=1 August 2010|archive-url=https://web.archive.org/web/20100803170454/http://news.xinhuanet.com/english2010/china/2010-08/01/c_13424634.htm|archive-date=3 August 2010|url-status=dead}} [66] => [67] => Three months later, on 1 November 2010, the sixth satellite was sent into orbit by LM-3C.{{cite news|url=http://english.gov.cn/2010-11/01/content_1735077.htm|title=China launches 6th satellite for indigenous global navigation, positioning network|publisher=gov.cn|date=1 November 2010|access-date=21 November 2010|archive-url=https://web.archive.org/web/20101231104817/http://english.gov.cn/2010-11/01/content_1735077.htm|archive-date=31 December 2010|url-status=dead}} [68] => [69] => Another satellite, the BeiDou-2/Compass IGSO-5 (fifth inclined geosynchronous orbit) satellite, was launched from the Xichang Satellite Launch Center by a [[Long March 3A]] on 1 December 2011 (UTC).{{cite news|url=http://www.gpsworld.com/gnss-system/news/beidou-launch-completes-regional-nav-system-12375/|title=Beidou Launch Completes Regional Nav System|publisher=GPS World|date=6 December 2010|access-date=23 December 2011 |url-status=dead|archive-url=https://web.archive.org/web/20120312083255/http://www.gpsworld.com/gnss-system/news/beidou-launch-completes-regional-nav-system-12375|archive-date=12 March 2012}} [70] => [[File:Chinese news rendering of Beidou satellite.png|thumb|274x274px|Rendering of BeiDou satellite on Chinese news television]] [71] => [72] => === Chinese involvement in Galileo system === [73] => In September 2003, China intended to join the European [[Galileo (satellite navigation)|Galileo positioning system]] project and was to invest €230 million (US$296 million, £160 million) in Galileo over the next few years.{{cite news|url=http://news.bbc.co.uk/1/hi/business/3121682.stm|title=China joins EU's satellite network|work=Business News|publisher=BBC News|date=19 September 2003|access-date=9 November 2006|archive-url=https://web.archive.org/web/20070107123439/http://news.bbc.co.uk/1/hi/business/3121682.stm|archive-date=7 January 2007|url-status=live}} At the time, it was believed that China's "BeiDou" navigation system would then only be used by its armed forces. [74] => [75] => In October 2004, China officially joined the Galileo project by signing the ''Agreement on the Cooperation in the Galileo Program between the "Galileo Joint Undertaking" (GJU) and the "National Remote Sensing Centre of China" (NRSCC)''.{{cite news|url=http://news.xinhuanet.com/newscenter/2005-07/29/content_3281533.htm|title=First contracts of the Galileo project signed, China is to invest 200 million Euro |publisher=[[Xinhua]]|date=29 July 2005|access-date=26 May 2010|language=zh|url-status=dead|archive-url=https://web.archive.org/web/20100211174817/http://news.xinhuanet.com/newscenter/2005-07/29/content_3281533.htm|archive-date=11 February 2010}} Based on the Sino-European Cooperation Agreement on Galileo program, China Galileo Industries (CGI),[https://web.archive.org/web/20140620234303/http://www.chinagi.com.cn/yw/index.asp China Galileo Industries (CGI)] the prime contractor of China's involvement in Galileo programs, was founded in December 2004.{{cite web|url=http://www.chinagi.com.cn/yw/gsjjxx.asp|title=About us|publisher=China Galileo Industries|access-date=26 May 2010|url-status=dead |archive-url=https://web.archive.org/web/20110707014516/http://www.chinagi.com.cn/yw/gsjjxx.asp|archive-date=7 July 2011}} By April 2006, eleven cooperation projects within the Galileo framework had been signed between China and the EU.{{cite news|url=http://news3.xinhuanet.com/politics/2006-04/13/content_4420183.htm|title=Eleven projects within the China-EU Galileo project have been signed and are carrying out|publisher=Xinhua|date=13 April 2006|access-date=26 May 2010|language=zh|url-status=dead|archive-url=https://web.archive.org/web/20110719045720/http://news3.xinhuanet.com/politics/2006-04/13/content_4420183.htm|archive-date=19 July 2011}} [76] => [77] => === Phase III === [78] => [[File:HK WCN 灣仔北 Wan Chai North 香港會展 HKCEC 創科博覽 InnoTech Expo 北斗衞星導航系統 BeiDou Navigation Satellite System IGSO GEO December 2022 Px3 08.jpg|thumb|alt=Model of Beidou Phase III satellite orbits.|Model of BeiDou Phase III satellite orbits]] [79] => [80] => * In November 2014, BeiDou became part of the World-Wide Radionavigation System (WWRNS) at the 94th meeting of the [[International Maritime Organization]] (IMO) Maritime Safety Committee,{{cite news |title=SOLAS amendments to make IGF Code mandatory approved by Maritime Safety Committee|url=http://www.imo.org/MediaCentre/PressBriefings/Pages/40-MSC94wrap.aspx|access-date=7 April 2015|work=Maritime Safety Committee (MSC), 94th session, 17–21 November 2014|publisher=[[International Maritime Organization]]|date=26 November 2014|archive-url=https://web.archive.org/web/20150407063948/http://www.imo.org/MediaCentre/PressBriefings/Pages/40-MSC94wrap.aspx|archive-date=7 April 2015|url-status=live}} which approved the "Navigation Safety Circular" of the BeiDou Navigation Satellite System (BDS).{{cite news|last1=Feng|first1=Bruce|title=A Step Forward for Beidou, China's Satellite Navigation System |url=http://sinosphere.blogs.nytimes.com/2014/12/04/a-step-forward-for-beidou-chinas-satellite-navigation-system/|newspaper=[[The New York Times]]|date=4 December 2014|access-date=7 April 2015|archive-url=https://web.archive.org/web/20150414153828/http://sinosphere.blogs.nytimes.com/2014/12/04/a-step-forward-for-beidou-chinas-satellite-navigation-system/|archive-date=14 April 2015|url-status=live}}{{cite news|title=Chinese Beidou Navigation Satellite System officially into Global Radio Navigation System|url=http://www.beidou.gov.cn/2014/12/01/2014120161d5b9e6272547ddb9d141b4129491f4.html |publisher=BeiDou|date=1 December 2014|access-date=7 April 2015|archive-url=https://web.archive.org/web/20150414154847/http://www.beidou.gov.cn/2014/12/01/2014120161d5b9e6272547ddb9d141b4129491f4.html|archive-date=14 April 2015|url-status=live}} [81] => * At Beijing time 21:52, 30 March 2015, the first new-generation BeiDou Navigation satellite (and the 17th overall) was successfully set to orbit by a [[Long March 3C]] rocket.{{cite web|last1=Barbosa |first1=Rui C.|title=Long March 3C in secretive launch with new Upper Stage|url=http://www.nasaspaceflight.com/2015/03/long-march-3c-launch-new-upper-stage/|publisher=[[NASASpaceFlight.com]]|date=30 March 2015 |access-date=7 April 2015|archive-url=https://web.archive.org/web/20150402104525/http://www.nasaspaceflight.com/2015/03/long-march-3c-launch-new-upper-stage/|archive-date=2 April 2015|url-status=live}}{{cite web|title=China successfully launched the first New-Generation Beidou Navigation Satellite |url=http://www.beidou.gov.cn/2015/04/01/20150401b4b91ddc213a45129a665ea3272b5aed.html|publisher=BeiDou|date=1 April 2015|access-date=7 April 2015|archive-url=https://web.archive.org/web/20150405232139/http://www.beidou.gov.cn/2015/04/01/20150401b4b91ddc213a45129a665ea3272b5aed.html|archive-date=5 April 2015|url-status=live}} [82] => * On 20 April 2019, a BeiDou satellite was successfully launched. Launch occurred at 22:41 [[Beijing time]], and the Long March 3B delivered the BeiDou navigation payload into an elliptical transfer orbit ranging between 220 kilometres and 35,787 kilometres, with an inclination of 28.5° to the equator, according to U.S. military tracking data.{{Cite web|url=https://spaceflightnow.com/2019/04/22/beidou-navigation-satellite-successfully-launched-by-china/|title=Beidou navigation satellite successfully launched by China – Spaceflight Now|last1=Clark|first1=Stephen|access-date=23 April 2019|archive-url=https://web.archive.org/web/20190423175749/https://spaceflightnow.com/2019/04/22/beidou-navigation-satellite-successfully-launched-by-china/|archive-date=23 April 2019|url-status=live}} [83] => * On 23 June 2020, the final BeiDou satellite was successfully launched, the launch of the 55th satellite in the BeiDou family. The third iteration of the BeiDou Navigation Satellite System provides global coverage for timing and navigation, offering an alternative to Russia's [[GLONASS]] and the European [[Galileo (satellite navigation)|Galileo positioning system]], as well as the US's [[GPS]].{{Cite web|url=https://phys.org/news/2020-06-china-satellite-gps-like-beidou.html|title=China launches final satellite in GPS-like Beidou system|publisher=phys.org|access-date=24 June 2020|archive-url=https://web.archive.org/web/20200624080233/https://phys.org/news/2020-06-china-satellite-gps-like-beidou.html|archive-date=24 June 2020|url-status=live}} [84] => [85] => === Use outside China === [86] => In 2018, the [[Pakistan Armed Forces]] received access to BeiDou for military purposes.{{Cite web |last=Baar |first=Jemima |date=1 March 2024 |title=BeiDou And Strategic Advancements in PRC Space Navigation |url=https://jamestown.org/program/beidou-and-strategic-advancements-in-prc-space-navigation/ |access-date=2024-03-01 |website=[[Jamestown Foundation]] |language=en-US}} In 2019, the Saudi [[Ministry of Defense (Saudi Arabia)|Ministry of Defense]] signed an agreement for military use of BeiDou. In 2020, Argentina entered into a cooperation agreement with China regarding the use of BeiDou.{{Cite journal |last=Aoyama |first=Rumi |date=2022-07-03 |title=China's dichotomous BeiDou strategy: led by the party for national deployment, driven by the market for global reach |journal=Journal of Contemporary East Asia Studies |language=en |volume=11 |issue=2 |pages=282–299 |doi=10.1080/24761028.2023.2178271 |issn=2476-1028 |doi-access=free}} In 2021, the first China-Africa BeiDou System Cooperation Forum was held in Beijing. In 2022, [[Vladimir Putin]] signed an agreement for the interoperability of BeiDou and [[GLONASS]].{{Cite web |date=2022-02-05 |title=China, Russia sign new satnav deal to strengthen position as GPS challengers |url=https://www.scmp.com/news/china/diplomacy/article/3165924/chinas-beidou-and-russian-glonass-sign-new-deal-rival-americas |access-date=2024-03-01 |website=[[South China Morning Post]] |language=en |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331103654/http://www.scmp.com/news/china/diplomacy/article/3165924/chinas-beidou-and-russian-glonass-sign-new-deal-rival-americas |url-status=live }} [87] => [88] => == BeiDou-3 == [89] => {{anchor|BeiDou-3}} [90] => [91] => [[File:Beidou atomic clock at CSTM 02.jpg|thumb|alt=Hydrogen maser used by Beidou-3.|[[Hydrogen maser]] used by BeiDou-3]] [92] => The third phase of the BeiDou system (BDS-3) includes three GEO satellites, three IGSO satellites, and twenty-four MEO satellites which introduce new signal frequencies B1C/B1I/B1A (1575.42{{nbsp}}MHz), B2a/B2b (1191.79{{nbsp}}MHz), B3I/B3Q/B3A (1268.52{{nbsp}}MHz), and Bs test frequency (2492.02{{nbsp}}MHz). Interface control documents on the new open signals were published in 2017–2018.[http://www.unoosa.org/documents/pdf/icg/2017/05_icg12.pdf Update on the BeiDou Satellite Navigation System] {{Webarchive|url=https://web.archive.org/web/20181023080137/http://www.unoosa.org/documents/pdf/icg/2017/05_icg12.pdf|date=23 October 2018}}. 12th ICG Meeting. Jia-Qing Ma, China Satellite Navigation Office. [93] => [94] => On 23 June 2020, the BDS-3 constellation deployment was fully completed after the last satellite was successfully launched at the [[Xichang Satellite Launch Center]].{{Cite web|title=APPLICATIONS-Transport|url=http://en.beidou.gov.cn/WHATSNEWS/202006/t20200623_20692.html|access-date=2020-06-23|website=en.beidou.gov.cn|archive-date=23 June 2020|archive-url=https://web.archive.org/web/20200623162635/http://en.beidou.gov.cn/WHATSNEWS/202006/t20200623_20692.html|url-status=live}}{{cite web|last1=Howell|first1=Elizabeth|title=China launches final Beidou satellite to complete GPS-like navigation system|url=https://www.space.com/china-launches-final-beidou-navigation-satellite.html#:~:text=China%20successfully%20launched%20the%20final,Launch%20Center%20in%20southwest%20China.|access-date=23 June 2020|website=Space.com|date=23 June 2020|language=en|archive-date=23 June 2020|archive-url=https://web.archive.org/web/20200623124137/https://www.space.com/china-launches-final-beidou-navigation-satellite.html#:~:text=China%20successfully%20launched%20the%20final,Launch%20Center%20in%20southwest%20China.|url-status=live}} BDS-3 satellites also include [[Satellite-based augmentation system|SBAS]] (B1C, B2a, B1A - GEO sats), [[Precise Point Positioning]] (B2b - GEO sats),[http://www.csno-tarc.cn/system/constellation&ce=english BeiDou satellite status] {{Webarchive|url=https://web.archive.org/web/20230811101026/http://www.csno-tarc.cn/system/constellation%26ce%3Denglish |date=11 August 2023 }} -- shows status of navigation, PPP, and SBAS services and [[search and rescue transponder]] (6 [[MEOSAR]]) capabilities.{{cite web|url=http://en.beidou.gov.cn/WHATSNEWS/201806/t20180615_15048.html|title=APPLICATIONS-Transport|website=en.beidou.gov.cn|access-date=22 October 2018|archive-url=https://web.archive.org/web/20181023034957/http://en.beidou.gov.cn/WHATSNEWS/201806/t20180615_15048.html|archive-date=23 October 2018|url-status=live}} [95] => [96] => {{multiple image [97] => | align = left [98] => | total_width = 600 [99] => | image1 = HK WCN 灣仔北 Wan Chai North 香港會展 HKCEC 創科博覽 InnoTech Expo 北斗衞星導航系統 BeiDou Navigation Satellite System IGSO GEO December 2022 Px3 05.jpg [100] => | image2 = HK WCN 灣仔北 Wan Chai North 香港會展 HKCEC 創科博覽 InnoTech Expo IGSO 傾斜地球同步軌道 Inclined GeoSynchronous Orbit GEO December 2022 Px3 01.jpg [101] => | image3 = Beidou-3 Satellite Mockup.jpg [102] => | footer = From left to right: Mockups of Beidou-3 satellites operating in [[Medium Earth orbit|MEO]], [[Inclined_orbit#Geosynchronous_orbits|IGSO]], and [[Geostationary orbit|GEO]] [103] => }} [104] => [105] => {| class="wikitable" style="text-align:center;" [106] => |+ Characteristics of BeiDou-2/Compass and BeiDou-3 signals{{cite web|url=http://ec.europa.eu/DocsRoom/documents/28325|title=European radio navigation plan (ERNP) |access-date=23 October 2018|archive-url=https://web.archive.org/web/20181024035636/http://ec.europa.eu/DocsRoom/documents/28325|archive-date=24 October 2018|url-status=live}} [107] => [108] => |- [109] => ! BeiDou signal || B1I || B1Q || B1C || B1A|| B2I || B2Q || B2a || B2b || B3I || B3Q || B3A [110] => |- [111] => ! GIOVE/Compass signal !! E2-I !! E2-Q !! E1-I !! E1-Q !! E5B-I !! E5B-Q !! E5a !! E5b !! E6-I !! E6-Q !! – [112] => |- [113] => |style="text-align:left;"| Access type || Open || Authorized || Open || Authorized|| Open || Authorized || Open || Open || Open || Authorized || Authorized [114] => |- [115] => |style="text-align:left;"| Code modulation || BPSK(2) || BPSK(2) || MBOC(6,1,1/11)|| BOC(14,2)|| BPSK(2) || BPSK(10) || AltBOC(15,10) || AltBOC(15,10)|| BPSK(10)|| BPSK(10)|| BOC(15,2.5) [116] => |- [117] => |style="text-align:left;"| Carrier frequency (MHz) || 1561.098|| 1561.098 || 1575.42 || 1575.42 || 1207.14 || 1207.14 || 1176.45 || 1207.14 ||1268.52 || 1268.52 || 1268.52 [118] => |- [119] => |style="text-align:left;"| Chip rate (Mchips/s) || 2.046 ||2.046 || || ||2.046 ||10.230 || || ||10.230||10.230|| [120] => |- [121] => |style="text-align:left;"| Code period (chips) || 2046 ||{{Dunno}}|| || ||2046|| ?? || || ||10230||{{Dunno}}|| [122] => |- [123] => |style="text-align:left;"| Code period (ms) || 1.0 ||>400 || || || 1.0||>160|| || || 1.0||>160|| [124] => |- [125] => |style="text-align:left;"| Symbols rate (bits/s) || 50 ||{{Dunno}}|| || || 50 ||{{Dunno}}|| || || 50 ||{{Dunno}}|| [126] => |- [127] => |style="text-align:left;"| Navigation frames (s) || 6 ||{{Dunno}}|| || || 6 ||{{Dunno}}|| || ||{{Dunno}}||{{Dunno}}|| [128] => |- [129] => |style="text-align:left;"| Navigation sub-frames (s) || 30 ||{{Dunno}}|| || || 30 ||{{Dunno}}|| || ||{{Dunno}}||{{Dunno}}|| [130] => |- [131] => |style="text-align:left;"| Navigation period (min) || 12.0 ||{{Dunno}}|| || || 12.0 ||{{Dunno}}|| || ||{{Dunno}}||{{Dunno}}|| [132] => |} [133] => Characteristics of the "I" signals on E2 and E5B are generally similar to the civilian codes of GPS (L1-CA and L2C), but Compass signals have somewhat greater power. The notation of Compass signals used in this page follows the naming of the frequency bands and agrees with the notation used in the American literature on the subject, but the notation used by the Chinese seems to be different.{{citation needed|date=June 2020}} [134] => [135] => There has also been an experimental [[S band]] broadcast called "Bs" at 2492.028 MHz, following similar experiments on BeiDou-1.{{cite journal |last1=秦 |first1=鹏霄 |title=S频段信号的研究 |journal=第四届中国卫星导航学术年会 |date=2013-05-15 |url=http://gb.oversea.cnki.net/KCMS/detail/detailall.aspx?filename=wxdh201305002012&dbcode=CPFD&dbname=CPFDREF |access-date=16 November 2020 |archive-date=5 May 2021 |archive-url=https://web.archive.org/web/20210505224740/https://gb.oversea.cnki.net/KCMS/detail/detailall.aspx?filename=wxdh201305002012&dbcode=CPFD&dbname=CPFDREF |url-status=dead }} [136] => [137] => == Predecessors == [138] => [139] => === BeiDou-1 === [140] => [[Image:Beidou-coverage.png|right|thumbnail|Coverage polygon of BeiDou-1]] [141] => [142] => BeiDou-1 was an experimental regional navigation system, which consisted of four satellites (three working satellites and one backup satellite). The satellites themselves were based on the Chinese [[Dong Fang Hong|DFH-3]] geostationary communications satellite and had a launch weight of 1,000 kg each.{{cite web|first1=Greg|last1=Goebel|url=http://www.vectorsite.net/ttgps_2.html#m3|title=International Navigation Satellite Systems|date=1 September 2008|publisher=vectorsite.net|access-date=6 April 2007|archive-url=https://web.archive.org/web/20151001153149/http://www.vectorsite.net/ttgps_2.html#m3|archive-date=1 October 2015 |url-status=live}} [143] => [144] => Unlike the American [[GPS]], Russian GLONASS, and European [[Galileo positioning system|Galileo]] systems, which use [[medium Earth orbit]] satellites, BeiDou-1 used satellites in [[geostationary orbit]]. This means that the system does not require a large constellation of satellites, but it also limits the coverage to areas on Earth where the satellites are visible. The area that can be serviced is from longitude 70° E to 140° E and from latitude 5° N to 55° N. The frequency of the system is 2,491.75 MHz.{{cite web |url=http://www.sinodefence.com/space/spacecraft/beidou1.asp|title=BeiDou 1 Experimental Satellite Navigation System|date=24 September 2008|publisher=SinoDefence.com|access-date=20 May 2010|url-status=dead |archive-url=https://web.archive.org/web/20100327075557/http://www.sinodefence.com/space/spacecraft/beidou1.asp|archive-date=27 March 2010}} [145] => [146] => ==== Completion ==== [147] => The first satellite, BeiDou-1A, was launched on 31 October 2000. The second satellite, BeiDou-1B, was successfully launched on 21 December 2000. The last operational satellite of the constellation, BeiDou-1C, was launched on 25 May 2003. [148] => [149] => ==== Position calculation ==== [150] => In 2007, the official [[Xinhua News Agency]] reported that the resolution of the BeiDou system was as low as 0.5 metre.{{cite web|url=http://orig.news.ifeng.com/mil/2/200707/0718_340_158622.shtml |title=BeiDou navigation system first goes to public, with resolution 0.5 metre|date=18 July 2007|publisher=[[Phoenix Television]]|access-date=19 May 2010|language=zh|url-status=dead |archive-url=https://web.archive.org/web/20090227184508/http://orig.news.ifeng.com/mil/2/200707/0718_340_158622.shtml|archive-date=27 February 2009}} With the existing user terminals it appears that the calibrated accuracy is 20 m (100 m, uncalibrated).{{cite web|url=http://www.navchina.com/english/productlist.asp?classid=12|title=BeiDou Products|publisher=BDStar Navigation|url-status=dead |archive-url=https://web.archive.org/web/20090105114653/http://www.navchina.com/english/productlist.asp?classid=12|archive-date=5 January 2009}} [151] => [152] => ==== Terminals ==== [153] => In 2008, a BeiDou-1 ground terminal cost around {{Currency|20000|RMB}} ({{Currency|2929}}), almost 10 times the price of a contemporary GPS terminal.{{cite web |url=http://tech.163.com/08/0628/08/4FGTUVT9000915BE.html|title=BeiDou-1 commercial controversy: 10 times the price of GPS terminal|publisher=[[NetEase]]|date=28 June 2008|access-date=23 May 2010|language=zh [154] => |archive-url=https://web.archive.org/web/20110721193808/http://tech.163.com/08/0628/08/4FGTUVT9000915BE.html|archive-date=21 July 2011|url-status=dead}} The price of the terminals was explained as being due to the cost of imported microchips.{{cite web|url=http://www.prlog.org/10112053-why-is-chinas-beidou-terminal-so-expensive.html|title=Why is China's Beidou terminal so expensive?|publisher=[[PRLog]] |date=31 August 2008|access-date=29 May 2010|archive-url=https://web.archive.org/web/20151015050315/http://www.prlog.org/10112053-why-is-chinas-beidou-terminal-so-expensive.html|archive-date=15 October 2015|url-status=live}} At the China High-Tech Fair ELEXCON of November 2009 in [[Shenzhen]], a BeiDou terminal priced at {{Currency|3000|CNY}} was presented.{{cite web |url=http://www.eetrend.com/news/100022852|title=3000Yuan BeiDou Satellite Positioning System terminal solution was presented at ELEXCON|publisher=eetrend.com|date=17 November 2009|access-date=29 May 2010 |language=zh|archive-url=https://web.archive.org/web/20100513015654/http://www.eetrend.com/news/100022852|archive-date=13 May 2010|url-status=dead}} [155] => [156] => ==== Applications ==== [157] => * Over 1000 BeiDou-1 terminals were used after the [[2008 Sichuan earthquake]], providing information from the disaster area.{{cite web|url=http://news.sohu.com/20080520/n256965516.shtml|title=Hongkong report: BeiDou-1 played an important role in rescuing, 7 nations providing free satellite data|publisher=Sohu|date=20 May 2008|access-date=23 May 2010|language=zh|archive-url=https://web.archive.org/web/20141208063058/http://news.sohu.com/20080520/n256965516.shtml|archive-date=8 December 2014|url-status=live}} [158] => * As of October 2009, all Chinese border guards in [[Yunnan]] were equipped with BeiDou-1 devices.{{cite web|url=http://news.sohu.com/20091014/n267346694.shtml|title=BeiDou-1 has equipped Yunnan troops, leading to command reform|publisher=Sohu|date=14 October 2009|access-date=23 May 2010|language=zh|archive-url=https://web.archive.org/web/20141208063304/http://news.sohu.com/20091014/n267346694.shtml|archive-date=8 December 2014|url-status=live}} [159] => [160] => [[Sun Jiadong]], the chief designer of the navigation system, said in 2010 that "Many organizations have been using our system for a while, and they like it very much".{{cite web |url=http://www.spacedaily.com/reports/China_To_Set_Up_Independent_Satellite_Navigation_System_999.html|title=China To Set Up Independent Satellite Navigation System|publisher=SpaceDaily.com|date=24 May 2010 |access-date=4 June 2010|archive-url=https://web.archive.org/web/20100527065040/http://www.spacedaily.com/reports/China_To_Set_Up_Independent_Satellite_Navigation_System_999.html|archive-date=27 May 2010|url-status=live}} [161] => [162] => ==== Decommissioning ==== [163] => BeiDou-1 was decommissioned at the end of 2012, after the BeiDou-2 system became operational. [164] => [165] => === BeiDou-2 === [166] => {{anchor|BeiDou-2}}{{anchor|Global system}} [167] => [[File:Beidou Navigation Satellite System 2012.png|thumb|Coverage polygon of BeiDou-2 in 2012]] [168] => [[Image:gps compass galileo frequency allocation Asimsky 05 2008.jpg|thumb|left|320px|Frequency allocation of [[GPS]], [[Galileo positioning system|Galileo]], and COMPASS; the light red color of E1 band indicates that the transmission in this band has not yet been detected.]] [169] => [170] => BeiDou-2 (formerly known as COMPASS){{Cite web|url=http://www.beidou.gov.cn/2012/12/27/20121227db0e01c98b044232875e2f85cf5bb2a3.html|title=The Logo Image of BeiDou Navigation Satellite System Issued [171] => |publisher=BeiDou.gov.cn|date=27 December 2012|access-date=1 January 2013|archive-url=https://web.archive.org/web/20150923183323/http://www.beidou.gov.cn/2012/12/27/20121227db0e01c98b044232875e2f85cf5bb2a3.html|archive-date=23 September 2015|url-status=dead}} is not an extension to the older BeiDou-1, but rather supersedes it outright. The new system is a constellation of 35 satellites, which include 5 geostationary orbit satellites for backward compatibility with BeiDou-1, and 30 non-geostationary satellites (27 in [[medium Earth orbit]] and 3 in inclined [[geosynchronous orbit]]),{{cite magazine [172] => |url=http://www.insidegnss.com/node/2134|title=China Launches Another Compass GEO Navigation Satellite|magazine=[[Inside GNSS]]|date=2 June 2010|access-date=4 June 2010 [173] => |archive-url=https://web.archive.org/web/20100611084624/http://www.insidegnss.com/node/2134|archive-date=11 June 2010|url-status=dead}} that offer complete coverage of the globe. [174] => [175] => The ranging signals are based on the [[CDMA]] principle and have complex structure typical of [[Galileo positioning system|Galileo]] or modernized [[GPS]]. Similar to the other [[satellite navigation|global navigation satellite systems]] (GNSSs), there are two levels of positioning service: open (public) and restricted (military). The public service is available globally to general users. When all the currently planned GNSSs are deployed, users of multi-constellation receivers will benefit from a total over 100 satellites, which will significantly improve all aspects of positioning, especially availability of the signals in so-called [[urban canyons]].G. Gibbons. China GNSS 101. ''Compass in the rearview mirror''. ''[[Inside GNSS]]'', January/February 2008, pp. 62–63 [http://www.insidegnss.com/auto/janfeb08-china.pdf] {{Webarchive|url=https://web.archive.org/web/20120302234100/http://www.insidegnss.com/auto/janfeb08-china.pdf|date=2 March 2012}} The general designer of the COMPASS navigation system is [[Sun Jiadong]], who is also the general designer of its predecessor, the original BeiDou navigation system.{{citation needed|date=June 2020}} All BeiDou satellites are equipped with laser [[retroreflector]] arrays for [[satellite laser ranging]]{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Zajdel |first2=Radosław |last3=Bury |first3=Grzegorz |last4=Bosy |first4=Jarosław |last5=Moore |first5=Michael |last6=Masoumi |first6=Salim |title=Quality assessment of experimental IGS multi-GNSS combined orbits |journal=GPS Solutions |date=2020 |volume=24 |issue=54 |doi=10.1007/s10291-020-0965-5 |bibcode=2020GPSS...24...54S |doi-access=free }} and the verification of the orbit quality.{{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=2019 |volume=93 |issue=12 |pages=2447–2463 |doi=10.1007/s00190-018-1143-1 |bibcode=2019JGeod..93.2447B |doi-access=free }}{{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 |year=2020 |volume=24 |issue=111 |doi=10.1007/s10291-020-01026-6 |bibcode=2020GPSS...24..111K |doi-access=free }} [176] => [177] => ==== Accuracy ==== [178] => There are two levels of service provided – a free service to civilians and licensed service to the [[Chinese government]] and military.{{cite web |url=http://www.beidou.gov.cn/2010/03/06/20100306e4ed1ecefebb41fa933ceee48024aa00.html|title=Introduction of the BeiDou Navigation Satellite System|publisher=BeiDou.gov.cn|date=15 January 2010|access-date=4 June 2010 [179] => |language=zh|archive-url=https://web.archive.org/web/20100318055953/http://www.beidou.gov.cn/2010/03/06/20100306e4ed1ecefebb41fa933ceee48024aa00.html|archive-date=18 March 2010|url-status=dead}}{{Cite news|last=Dotson|first=John|date=15 July 2020|title=The Beidou Satellite Network and the "Space Silk Road" in Eurasia|url=https://jamestown.org/program/the-beidou-satellite-network-and-the-space-silk-road-in-eurasia/|access-date=2020-07-16|newspaper=Jamestown|language=en-US|archive-date=16 July 2020|archive-url=https://web.archive.org/web/20200716094445/http://jamestown.org/program/the-beidou-satellite-network-and-the-space-silk-road-in-eurasia/|url-status=live}} The free civilian service has a 10-metre location-tracking accuracy, synchronizes clocks with an accuracy of 10 nanoseconds, and measures speeds to within 0.2 m/s. The restricted military service has a location accuracy of 10 cm,{{cite web|url=http://earth.scichina.com:8080/sciDe/EN/abstract/abstract507876.shtml|title=Precise orbit determination of Beidou Satellites with precise positioning|work=Science China|year=2012|access-date=26 June 2013|archive-url=https://web.archive.org/web/20130617060128/http://earth.scichina.com:8080/sciDe/EN/abstract/abstract507876.shtml|archive-date=17 June 2013|url-status=dead}} can be used for communication, and will supply information about the system status to the user.{{citation needed|date=June 2020}} In 2019, the International GNSS Service started providing precise orbits of BeiDou satellites in experimental products. [180] => [181] => To date, the military service has been granted only to the [[People's Liberation Army]] and to the [[Pakistan Armed Forces]].{{cite web |url=https://www.theregister.co.uk/2012/05/17/beidou_ready_2012_three_satellites/|title=GPS rival Beidou will cover Asia Pac by end of the year|work=The Register|date=17 May 2012|access-date=26 June 2013 |archive-url=https://web.archive.org/web/20130728033955/http://www.theregister.co.uk/2012/05/17/beidou_ready_2012_three_satellites/|archive-date=28 July 2013|url-status=live}}{{cite web |url=http://www.spacesafetymagazine.com/tag/beidou/|title=US Department of Defense Reports on China's Space Capabilities|work=Space Safety Magazine|date=27 May 2013|access-date=26 June 2013|archive-url=https://web.archive.org/web/20131115010911/http://www.spacesafetymagazine.com/tag/beidou/|archive-date=15 November 2013|url-status=live}}{{cite web|url=http://www.nextbigfuture.com/2016/06/china-will-make-beidou-navigation.html|title=China will make BeiDou Navigation Satellite System available to global users by 2020|work=Next Big Future|date=28 June 2016|access-date=3 February 2017|archive-url=https://web.archive.org/web/20170203162403/http://www.nextbigfuture.com/2016/06/china-will-make-beidou-navigation.html|archive-date=3 February 2017|url-status=live}} [182] => [183] => ==== Frequencies ==== [184] => Frequencies for COMPASS are allocated in four bands: E1, E2, E5B, and E6; they overlap with Galileo. The fact of overlapping could be convenient from the point of view of the receiver design, but on the other hand raises the issues of system interference, especially within E1 and E2 bands, which are allocated for Galileo's publicly regulated service.''Galileo, Compass on collision course'', GPS World, April 2008, p. 27 However, under [[International Telecommunication Union]] (ITU) policies, the first nation to start broadcasting in a specific frequency will have priority to that frequency, and any subsequent users will be required to obtain permission prior to using that frequency, and otherwise ensure that their broadcasts do not interfere with the original nation's broadcasts. As of 2009, it appeared that Chinese COMPASS satellites would start transmitting in the E1, E2, E5B, and E6 bands before Europe's Galileo satellites and thus have primary rights to these frequency ranges.{{cite web|last1=Levin|first1=Dan |url=https://www.nytimes.com/2009/03/23/technology/23iht-galileo23.html?_r=1&scp=1&sq=chinese%20europe%20galileo&st=cse|title=''Chinese square off with Europe in space''|location=China|work=[[The New York Times]] |date=23 March 2009|access-date=30 December 2011|archive-url=https://web.archive.org/web/20110501220951/http://www.nytimes.com/2009/03/23/technology/23iht-galileo23.html?_r=1&scp=1&sq=chinese%20europe%20galileo&st=cse |archive-date=1 May 2011|url-status=live}} [185] => [186] => ==== Compass-M1 ==== [187] => Compass-M1 is an experimental satellite launched for signal testing and validation and for the frequency filing on 14 April 2007. The role of Compass-M1 for Compass is similar to the role of the [[GIOVE]] satellites for the Galileo system. The orbit of Compass-M1 is nearly circular, has an altitude of 21,150 km and an inclination of 55.5°.{{citation needed|date=June 2020}} [188] => [189] => The investigation of the transmitted signals started immediately after the launch of Compass-M1 on 14 April 2007. Soon after in June 2007, engineers at [[CNES]] reported the spectrum and structure of the signals.T. Grelier, J. Dantepal, A. Delatour, A. Ghion, L. Ries, ''Initial observation and analysis of Compass MEO satellite signals'', ''[[Inside GNSS]]'', May/June 2007 [http://www.insidegnss.com/auto/IG0607_CompassFinal.pdf] {{Webarchive|url=https://web.archive.org/web/20120302235143/http://www.insidegnss.com/auto/IG0607_CompassFinal.pdf|date=2 March 2012}} A month later, researchers from [[Stanford University]] reported the complete decoding of the "I" signals components.G. Xingxin Gao, A. Chen, S. Lo, D. De Lorenzo, P. Enge, GNSS over China. ''The Compass MEO satellite codes''. ''[[Inside GNSS]]'', July/August 2007, pp. 36–43 [http://www.insidegnss.com/auto/IG0807_Gao-Lo_final.pdf] {{Webarchive|url=https://web.archive.org/web/20120302234816/http://www.insidegnss.com/auto/IG0807_Gao-Lo_final.pdf|date=2 March 2012}}G. Xingxin Gao, A. Chen, Sh. Lo, D. De Lorenzo and Per Enge, ''Compass-M1 broadcast codes and their application to acquisition and tracking'', Proceedings of the ION National Technical Meeting 2008, San Diego, California, January 2008.{{cite web |url=http://www.stanford.edu/~gracegao/publications/ION_NTM_08%20Compass.pdf|title=Compass-M1 Broadcast Codes and Their Application to Acquisition and Tracking|access-date=8 February 2016|url-status=dead |archive-url=https://web.archive.org/web/20121020031639/http://www.stanford.edu/~gracegao/publications/ION_NTM_08%20Compass.pdf|archive-date=20 October 2012}} The knowledge of the codes allowed a group of engineers at [[Septentrio]] to build the COMPASS receiverW. De Wilde, F. Boon, J.-M. Sleewaegen, F. Wilms, ''More Compass points. Tracking China’s MEO satellite on a hardware receiver''. ''[[Inside GNSS]]'', July/August 2007, pp. 44–48. [http://www.insidegnss.com/auto/IG0807-DeWilde_etal_final.pdf] {{Webarchive|url=https://web.archive.org/web/20120208123235/http://www.insidegnss.com/auto/IG0807-DeWilde_etal_final.pdf|date=8 February 2012}} and report tracking and multipath characteristics of the "I" signals on E2 and E5B.A. Simsky, D. Mertens, Wim De Wilde, ''Field Experience with Compass-M1 E2 and E5B Signals''. Proceedings of ENC GNSS 2008, Toulouse, 22–25 April 2008. [190] => [191] => ==== Operation ==== [192] => [[File:Ground track beidou-m2 satellite.jpg|thumb|right|[[Ground track]] of BeiDou-M5 (2012-050A)]] [193] => [194] => In December 2011, the system went into operation on a trial basis.{{cite news|url=http://europe.chinadaily.com.cn/business/2011-12/28/content_14343656.htm|title=Satellite navigation system launched|work=China Daily|date=28 December 2010|access-date=29 December 2011|archive-url=https://web.archive.org/web/20131224102604/http://europe.chinadaily.com.cn/business/2011-12/28/content_14343656.htm |archive-date=24 December 2013|url-status=live}} It started providing navigation, positioning and timing data to China and the neighbouring area for free from 27 December 2011. During this trial run, Compass offered positioning accuracy to within 25 metre and the precision improved as more satellites were launched. Upon the system's official launch, it pledged to offer general users positioning information accurate to the nearest 10 m, measure speeds within 0.2 metre per second, and provide signals for clock synchronisation accurate to 0.02 microseconds.{{cite news |url=https://www.bbc.co.uk/news/technology-16337648|title=China GPS rival Beidou starts offering navigation data|publisher=[[BBC]]|date=27 December 2010|access-date=29 December 2011|archive-url=https://web.archive.org/web/20120203001904/http://www.bbc.co.uk/news/technology-16337648|archive-date=3 February 2012|url-status=live}} [195] => [196] => The BeiDou-2 system began offering services for the Asia-Pacific region in December 2012. At this time, the system could provide positioning data between longitude 55° E to 180° E and from latitude 55° S to 55° N.{{Cite web|url=http://www.beidou.gov.cn/2012/12/26/20121226bac9c0de3e6b430d997368b19ff2c6b5.html|script-title=zh:"5+5+4"这样的星座结构有什么特点？|publisher=WWW.BEIDOU.GOV.CN |date=26 December 2012|access-date=3 January 2013|language=zh|archive-url=https://web.archive.org/web/20130324195232/http://www.beidou.gov.cn/2012/12/26/20121226bac9c0de3e6b430d997368b19ff2c6b5.html|archive-date =24 March 2013|url-status=dead}} [197] => [198] => The new-generation BeiDou satellites support short message service. [199] => [200] => ==== Completion ==== [201] => In December 2011, [[Xinhua]] stated that "[t]he basic structure of the BeiDou system has now been established, and engineers are now conducting comprehensive system test and evaluation. The system will provide test-run services of positioning, navigation and time for China and the neighboring areas before the end of this year, according to the authorities".{{cite web |url=http://news.xinhuanet.com/english2010/sci/2011-12/02/c_131283096.htm|title=China launches 10th satellite for independent navigation system|date=2 December 2011|publisher=Xinhua|access-date=23 December 2011|archive-url=https://web.archive.org/web/20120106093417/http://news.xinhuanet.com/english2010/sci/2011-12/02/c_131283096.htm|archive-date=6 January 2012|url-status=dead}} The system became operational in the China region that same month. The global navigation system should be finished by 2020.{{cite web|url=http://news.xinhuanet.com/mil/2010-03/03/content_13087844.htm|title=BeiDou navigation system covers Asia-Pacific region till 2012|date=3 March 2010|publisher=Xinhua News Agency|access-date=19 May 2010|language=zh|archive-url=https://web.archive.org/web/20100309230826/http://news.xinhuanet.com/mil/2010-03/03/content_13087844.htm|archive-date=9 March 2010|url-status=dead}} [202] => [203] => As of December 2012, 16 satellites for BeiDou-2 had been launched, with 14 in service. As of December 2017, 150 million Chinese smartphones (20% of the market) were equipped to utilize BeiDou.{{Cite news|url=http://www.theworldin.com/article/14433/edition2018digital-silk-road|title=A digital Silk Road|access-date=3 December 2017|archive-url=https://web.archive.org/web/20171204171153/http://www.theworldin.com/article/14433/edition2018digital-silk-road|archive-date=4 December 2017|url-status=live}} [204] => [205] => == Constellations == [206] => {|class="wikitable" style="float:right; margin:0 0 1em 1em;" [207] => |+ Summary of satellites, as of 19 May 2023 [208] => ! rowspan="2" | Block [209] => ! rowspan="2" | Launch
period [210] => ! colspan="3" | Satellite launches [211] => ! rowspan="2" | Currently in orbit
and healthy [212] => |- [213] => ! Success || Failure || Planned [214] => |- [215] => ! 1 [216] => | 2000–2006 || 4 || 0 || 0 || 0 [217] => |- [218] => ! 2 [219] => | 2007–2019 || 20 || 0 || 0 || 15 [220] => |- [221] => ! 3 [222] => | 2015–present || 36 || 0 || 0 || 31 [223] => |- [224] => ! colspan="2" | Total [225] => | 60 || 0 || 0 || 46 [226] => |} [227] => {{main|List of BeiDou satellites}} [228] => The regional BeiDou-1 system was decommissioned at the end of 2012.{{citation needed|date=June 2020}} [229] => [230] => The first satellite of the second-generation system, Compass-M1 was launched in 2007. It was followed by further nine satellites during 2009–2011, achieving functional regional coverage. A total of 16 satellites were launched during this phase.{{citation needed|date=June 2020}} [231] => [232] => In 2015, the system began its transition towards global coverage with the first launch of a new-generation of satellites, and the 17th one within the new system. On 25 July 2015, the 18th and 19th satellites were successfully launched from the [[Xichang Satellite Launch Center]], marking the first time for China to launch two satellites at once on top of a [[Long March 3B]]/[[Expedition 1]] [[launch vehicle|carrier rocket]]. The Expedition-1 is an independent [[Multistage rocket|upper stage]] capable of delivering one or more spacecraft into different orbits. On 29 September 2015, the 20th satellite was launched, carrying a [[hydrogen maser]] for the first time within the system.{{cite web|url=http://www.beidou.gov.cn/2015/09/30/201509303994d237a4c8419e925c86df8f5e1c32.html |title=我国成功发射第四颗新一代北斗导航卫星|publisher=beidou.gov.cn|date=30 September 2015|access-date=24 December 2016|archive-url=https://web.archive.org/web/20161225080021/http://www.beidou.gov.cn/2015/09/30/201509303994d237a4c8419e925c86df8f5e1c32.html|archive-date=25 December 2016|url-status=live}} [233] => [234] => In 2016, the 21st, 22nd and 23rd satellites were launched from [[Xichang Satellite Launch Center]],{{cite web|url=http://www.beidou.gov.cn/2016/02/01/20160201acefeef4af98428dad6b46b83a72b179.html|title=我国成功发射第五颗新一代北斗导航卫星|publisher=beidou.gov.cn|date=1 February 2016|access-date=24 December 2016|archive-url=https://web.archive.org/web/20170510110643/http://www.beidou.gov.cn/2016/02/01/20160201acefeef4af98428dad6b46b83a72b179.html|archive-date=10 May 2017|url-status=live}} the last two of which entered into service on 5 August and 30 November, respectively.{{cite web|url=http://www.beidou.gov.cn/2016/08/05/20160805be35373a002d45788fc4b8e4b798750c.html|title=第22颗北斗导航卫星正式入网提供服务 |publisher=beidou.gov.cn|date=5 August 2016|access-date=24 December 2016|archive-url=https://web.archive.org/web/20161225090148/http://www.beidou.gov.cn/2016/08/05/20160805be35373a002d45788fc4b8e4b798750c.html |archive-date=25 December 2016|url-status=live}}{{cite web|url=http://www.beidou.gov.cn/2016/11/30/201611304b14b49a9cca4afa99b25abb519a9cee.html|title=第23颗北斗导航卫星入网工作|publisher=beidou.gov.cn |date=30 November 2016|access-date=24 December 2016|archive-url=https://web.archive.org/web/20161225083137/http://www.beidou.gov.cn/2016/11/30/201611304b14b49a9cca4afa99b25abb519a9cee.html|archive-date=25 December 2016|url-status=live}} [235] => [236] => Orbital period: 12 hours and 53 minutes (every 13 revolutions, done in 7 sidereal days, [[Satellite revisit period|a satellite passes over the same location]]).{{Cite book |last1=Aswal |first1=Dinesh K. |url=https://books.google.com/books?id=I73SEAAAQBAJ&pg=PA512 |title=Handbook of Metrology and Applications |last2=Yadav |first2=Sanjay |last3=Takatsuji |first3=Toshiyuki |last4=Rachakonda |first4=Prem |last5=Kumar |first5=Harish |date=2023-08-23 |publisher=Springer Nature |isbn=978-981-99-2074-7 |pages=512 |language=en |access-date=30 November 2023 |archive-date=30 October 2023 |archive-url=https://web.archive.org/web/20231030101033/https://books.google.be/books?id=I73SEAAAQBAJ&pg=PA512&lpg=PA512 |url-status=live }} [237] => [238] => {{multiple image [239] => | align = left [240] => | direction = horizontal [241] => | width = 250 [242] => | header = Animation of BeiDou-3 [243] => [244] => | image1 = Animation of BeiDou-3 orbit around Earth.gif [245] => | caption1 = Around the Earth [246] => [247] => | image2 = Animation of BeiDou-3 orbit around Earth - Polar view.gif [248] => | caption2 = Around the Earth – polar view [249] => [250] => | image3 = Animation of BeiDou-3 orbit - Earth fixed - front view.gif [251] => | caption3 = [[ECEF|Earth fixed frame]] – equatorial view, front [252] => [253] => | image4 = Animation of BeiDou-3 orbit - Earth fixed - side view.gif [254] => | caption4 = [[ECEF|Earth fixed frame]] – equatorial view, side [255] => [256] => | footer = {{legend-inline| RoyalBlue | Earth}}{{·}}{{legend-inline| magenta | I1 }}{{·}}{{legend-inline| lime | I2 }}{{·}}{{legend-inline| Cyan | I3}}{{·}}{{legend-inline| Gold | G1}}{{·}}{{legend-inline| OrangeRed | G2}}{{·}}{{legend-inline| Gainsboro | G3}} [257] => }} [258] => {{clear}} [259] => [260] => == Prohibitions == [261] => In 2018, Taiwan's [[National Communications Commission]] announced that it would be illegal to use BeiDou products in Taiwan without its approval.{{Cite web |date=2023-11-14 |title=Drug smuggling fishermen used Chinese sat nav to avoid detection |url=https://focustaiwan.tw/society/202311140027 |access-date=2023-11-14 |website=[[Focus Taiwan]] |language=en-US |quote=Since 2018, the NCC has banned the use of BeiDou Navigation Satellite System products without approval, and asked related agencies to confiscate such equipment from those found illegally importing, using or selling it. |archive-date=14 November 2023 |archive-url=https://web.archive.org/web/20231114200408/https://focustaiwan.tw/society/202311140027 |url-status=live }} [262] => [263] => == See also == [264] => {{Portal|Spaceflight|China}} [265] => *[[Restrictions on geographic data in China#Coordinate systems|Chinese coordinate systems]] [266] => [267] => == References == [268] => {{Reflist}} [269] => [270] => == External links == [271] => * {{Official website}} [272] => [273] => {{CNSA space program}} [274] => {{Satellite navigation systems}} [275] => {{Satellite constellations}} [276] => {{Time signal stations}} [277] => {{Chinese satellites}} [278] => {{Portal bar|Spaceflight|Geography|Transport|China}} [279] => [280] => {{DEFAULTSORT:Beidou Navigation System}} [281] => [[Category:BeiDou| ]] [282] => [[Category:Navigation satellite constellations]] [283] => [[Category:Space program of the People's Republic of China]] [284] => [[Category:Satellites of China]] [285] => [[Category:Spacecraft launched by Long March rockets]] [] => )

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BeiDou

BeiDou is a Chinese satellite navigation system developed to provide positioning, navigation, and timing services. The name BeiDou originates from the Chinese term for the North Star, which has been used in China for thousands of years as a navigational reference.

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The name BeiDou originates from the Chinese term for the North Star, which has been used in China for thousands of years as a navigational reference. The development of BeiDou began in the early 1990s, with the first experimental satellite launched in 2000. Since then, the system has been expanded with more satellites, and it has achieved regional coverage by 2012. The Chinese government has plans to complete the global coverage of BeiDou by 2020. BeiDou aims to provide an alternative to the dominant navigation systems such as the Global Positioning System (GPS) developed by the United States and Russia's GLONASS. It offers services for various sectors, including transportation, agriculture, disaster relief, and military applications. The system consists of three components: the space segment, which includes satellites in geostationary and inclined orbits; the ground control segment, responsible for overall system management and monitoring; and the user segment, which includes receivers used to access the system. The advantages of BeiDou include its ability to provide more accurate positioning for users in the Asia-Pacific region, which GPS signals may struggle to penetrate due to their relatively weaker strength. Additionally, with its global coverage, BeiDou can enhance the reliability and availability of positioning services worldwide. BeiDou has gone through multiple generations of satellites, with each generation offering improved accuracy, availability, and signal quality. The system is also designed to be compatible and interoperable with other satellite navigation systems, promoting global navigation coordination and cooperation. As of 2020, the BeiDou system is fully operational in the Asia-Pacific region and is expected to provide global coverage by the same year. With its advancements, BeiDou has become an important player in the satellite navigation field, offering a reliable and independent alternative to existing systems.

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