Bài giảng GPS (Global Positioning System)

Students: Nguyễn Ngọc Quân Nguyễn Văn Bình Hoàng Văn ToànInstructor: Dr.Pham Nguyen Thanh LoanGPS(Global Positioning System)ContentsGPS1234DefinitionStructure of GPSHow does GPS work (positioning)?	ApplicationsDefinitionThe Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth’s surface. Maintained by the United States government in 1995.Freely accessible to anyone with a GPS receiver.Advantages High precision. Available for users. Working 24h/day in all weather.Structure of GPSGPSUserSegmentSpace SegmentControlSegmentStructure of GPSSpace segment1 System of 24 artificial satellites rotating in 6 ellipse orbits. 4 satellites in each orbit. 6 orbits have 55° inclination relative to Earth’s equator. Orbiting at an altitude of approximately 20,200 km. The orbital period is 11 hours and 58 minutes.Structure of GPSSpace segment1 The function of satellite: Receive and save the data transferred from the control segment. Provide the accurate time by using the standard atomic frequency on the satellite. Transfer information and signal in one or two frequency.Structure of GPSSpace segment1Structure of GPSControl segment2 5 control stations: 1 master station (MSC) and 4 monitor stations. Tracking, monitoring the satellites and transferring data to the MSC. The MSC: processing the data to calculate and control the orbit of satellites. 3 stations of them: loading the data into the satellites.Structure of GPSControl segment2Structure of GPSControl segment2Structure of GPSUser segment3Structure of GPSLock on to satellitesCalculate the pseudo range to each satelliteGet the satellite position coordinatesCalculate receiver positionConvert to geographic position and universal time GPS receiverUser segment3Structure of GPSUser segment – How to calculate the pseudo range ?3Errors on GPS signalHow does GPS work?Relative positioningPoint positioningPositioningHow does GPS work?Point positioning1How does GPS work?Point positioning1How does GPS work?Point positioning1How does GPS work?Point positioning1At least 4 satellites are required to calculate the time error variable, Ip , Tp and ε. Calculate (r), solve the system of equation to find (x,y,z).How does GPS work?Relative positioning2Using 2 receiver devices to receive signal from common satellites at the same time.Result: the baseline vector.More accurate than point positioning.ApplicationsPositioning: to define the exact position.Guiding: GPS + map Weather forecast. Applications in: education, exploiting petroleum and gas complexThank for listening !