全球导航定位系统GNSS,Global Navigation Satellite System,1,2,3,contents,The brief introduction of GNSS,The constellations of GNSS,The application of GNSS,1.The brief introduction of GNSS,It is constellation of satellites designed to provide positioning and timing information for users on earth or in space. It is refers to all the global and regional satellite navigation system and the enhance system.,The component of GNSS,GPS,GLONASS,Beidou,GNSS,GALILEO,1.The brief introduction of GNSS,2.The Constellations of GNSS,2.1 GPS Basic Information 24 satellites 6 orbital planes on almost circular orbits an altitude of about 20,200km above the surface of the earth inclined by 55 with respect to the equator orbital periods of approximately 11 hours 58minutes designed and realized by the U.S. Department of Defense the military application, commercial and public sector users,2.1 GPS GPS has made a considerable impact on almost all positioning ,navigation, timing and monitoring applications. It provides particularly coded satellite signals that can be processed in a GPS receiver , allowing the receiver to estimate position , velocity and time . Eg : placing GPS receivers on ocean buoys to measure wave height and direction ,monitoring the earths crustal deformations, and sensing the atmosphere using occultation techniques , such as those accomplished using CHAMP satellite.,2.The Constellations of GNSS,2.2 GLONASS Basic Information 24 satellites (12 October,1982 1995) In 3 orbit separated by 64.8 in the equatorial plane An altitude of about 19,130 km above the ground surface An orbital period of 11:15:14 Operated by the Ministry of Defense of the Russian Federation.,2.The Constellations of GNSS,2.2 GLONASS Future The future seemed uncertain due to economic problems facing the Russian Federation over the past few years. The number of operational satellites was steadily decreasing. As of January 2006,a total of 10 satellites are operational . But GLONASS was recovered and restored in 2011. In recent years , uncertainty about the future of the GLONASS system has limited the demand and availability of receivers to process the signals.,2.The Constellations of GNSS,2.3 Galileo Basic Information 30 satellites 3 orbital planes on almost circular orbits an altitude of about 23,222km above the surface of the earth inclined by 56 with respect to the equator orbital periods of approximately 13 hours designed and realized by European Union,2.The Constellations of GNSS,2.3 Galileo It is Europes initiative for a state-of-the-art global navigation satellite system , providing a highly accurate , guaranteed global positioning service under civilian control. It will provide autonomous navigation and positioning service, but at the same time will be interoperable with the two other global satellite navigation systems : GPS and GLONASS. By providing dual frequencies as standard , Galileo will deliver real-time positioning accuracy down to the meter range.,2.The Constellations of GNSS,2.4 BeiDou /Compass Basic Information 35 satellites (5 GEO + 30 MEO) In 3 orbit separated by 55 in the equatorial plane An orbital period of 12hours 55 minutes Created and operated by China,2.The Constellations of GNSS,2.4 BeiDou /Compass The BeiDou is Chinas entry into the realm of GNSS. China will build BeiDou covering the whole world in 2020. BeiDou will share many features in common with GPS and Galileo, providing the potential for low cost integration of these signals into a GPS/Galileo/BeiDou receiver . These commonalities include multiple frequencies , signal structure and services.,2.The Constellations of GNSS,The application of GNSS,1.Personal navigation,2.Aviation application,3.Automotive application,4.Weak signal navigation,5.Marine application,6.Space application,7.Agriculture , forestry and natural resource exploration,8.Geodesy and surveying,9.Scientific application,THANK YOU,