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The global COMPASS system will be built by 2020 [4] and it is being designed to offer the following performances for each COMPASS Services [5] [3] : Open service : a free service for civilian users with positioning accuracy of within 10 meters, velocity accuracy of within 0.2 m/s and timing accuracy of within 20 nanoseconds. The Open Service is planned to be available a few years ahead of the system full operational capability; Authorized service : a licensed service with higher accuracy even in complex situations for authorized and military users only. Wide area differential positioning service : with positioning accuracy of 1 m. Short message service (SMS) : up to 120 Chinese characters. Table 1 : COMPASS Signals Characteristics [6] Preliminary performance figures were presented in the COMPASS Workshop, integrated in the ION GNSS 2011 Conference. The COMPASS constellation available at the time (referred to as "3+3", standing for 3 GEO Satellites a...

Sometimes more overt forms of shaping domestic markets arise. Both Russia and China have announced plans to require commercial transportation operators in their countries to use their respective national GNSS systems. Russia has also drawn criticism for its efforts t o impose tariffs on imports of navigation devices that don’t incorporate GLONASS capability , and Europe once proposed fees on receivers that would have taxed GPS as well as Galileo. Russia’s recent announcement to require civil aircraft op erating in its domestic airspace to carry GLONASS equipment has caused a controversy still under way at ICAO and among aircraft manufacturers. China has yet to reveal any regulatory plans that would affect foreign companies entering its domestic market with BeiDou-capable products, although the nation’s Certification and Accreditation Administration (CNCA) says it will establish “an authoritative testing and certification system” for BeiDou equipment by 2015.  I...

compass on the road to global positioning system compass( current 5+5+4 constellation and regional tracking system) Tgd: 2 ~ 30 ns.with variation modelled and predicted to be better than 1.0 ns Compass Ionosphere model shows better performance than GPS model for single frequency receivers Better than 10m accuracy for dual frequency civilian users, 2m for authorized users Better than 5 cm for post-processing positioning using daily phase data From Shanghai Astronomical Observatory ( SHAO) Jan 2012 According to Xinhua news agency reports, Ran said Beidou’s general functionality and performance within China was “comparable” to the GPS system, with stand-alone positioning accuracy of 10 meters, velocity accuracy of 0.2 meters per second, and one-way timing accuracy of 50 nanoseconds. In the lower graphs, presenting the I/Q constellation diagrams, the authors point out an obvious improvement of the modulation quality over time and generations, especially of the lat...

Compass/BeiDou-2, China’s GNSS program will launch 5 satellites this year to join the 11 already in orbit, according to Li Xing, a representative of the China Satellite Navigation Office. This will support a planned declaration of initial operational capability (IOC) for a regional system covering 84˚E to 160˚E and 55˚S to 55˚N, he said at the Munich Satellite Navigation Summit in March. The rapid development of the Chinese system was refelcted in the allocation of its own session during this year’s Summit, the most important GNSS policy gathering in Europe. Professor Zhao Qile of Wuhan University’s GNSS research center said the positioning accuracy of 10–20 meters within that region available with the current constellation is expected to improve to 5 to 10 meters, based on a 5+5+4 (GEO, IGSO, MEO) configuration by the end of 2012. Mao Gang, applications director for Unicore Communications Inc., a Beijing-based GNSS manufacturer, described progress that his and other com...

The Russian Defense Ministry has reportedly refused to adopt GLONASS, the country’s rival to GPS, due to its technical shortcomings. One of the system’s 24 satellites has malfunctioned, and besides, GLONASS is still in its testing phase. ­The malfunctioning satellite will not be operational any time soon as it has already exhausted its power after 96 months in service, Nezavisimaya Gazeta reports. And due to a difference in orbit inclination, no existing reserve satellite can substitute it. A backup satellite launched in December 2008 stopped working in September of this year, allegedly because of malfunctioning Taiwanese-made microchips. According to the report, Moscow was forced to order the microchips from Taiwan when the US, Japan and several other NATO countries refused to supply the GLONASS manufacturers with spare parts following Russia’s war with South Ossetia. Though three GLONASS-M satellites are reportedly ready to be put into orbit, Russia’s...