GPS

GPS INDEX • • • • • • • • • • WHAT IS GPS USES OF GPS NEED FOR GPS PRINCIPLES OF GPS APPLICATIONS HOW TO WORK SATELLITE SYSTEM SATELLITE CONSTELLATION OPERATION CONTROL SYSTEM CONCLUSION What is GPS? • Global Positioning System(GPS) is technology that can be your accurate position anywhere on the earth (latitude/longitude). You need a special GPS receiver that can receive signals from satellites. USES OF GPS • Agriculture & forming • Camera & photography • Recreation NEED FOR GPS DEVICE • A GPS device can be used for many things. From giving you turn-by-turn directions on a map to measuring time with great accuracy. • The GPS provides quickly,accurately the time position &velocity of the object any where on the global at any time. Principles of GPS • GPS employs time of arrival(TOA) ranging for user position determination • Three dimensional position location via intersection of multiple spheres Applications of GPS ROADS&HIGHWAYS SPACE RAILS AGRICULTURE MARINE AIVIATION How to GPS works? • The GPS system consists of three pieces.There are the satellites that transmit the position information, there are the ground stations that are used to control the satellites and update the information,and finally there is the receiver that you purchased. It is the receiver that collects the data from satellites and computes its location anywhere in the world based on information it gets from satellites. GPS satellite system • The 24 satellites that make up the GPS space segment are orbiting the earth about 12,000 miles above us. They are constantly moving, making two complete orbits in less than 24 hours. These satellites are travelling at speeds of roughly 7,000 miles an hour. GPS satellites are powered by solar energy. They have backup batteries onboard to keep them running in the event of a solar eclipse, when there's no solar power. Small rocket boosters on each satellite keep them flying in the correct path. Here are some other interesting facts about the GPS satellites (also called NAVSTAR, the official U.S. Department of Defense name for GPS): The first GPS satellite was launched in 1978. • • • • A full constellation of 24 satellites was achieved in 1994. • Each satellite is built to last about 10 years. Replacements are constantly being built and launched into orbit. • A GPS satellite weighs approximately 2,000 pounds and is about 17 feet across with the solar panels extended. • Transmitter power is only 50 watts or less Satellite constellation • • • • • • • A sufficient number of satellites,to ensure that four are always electronically visible , are required for continuous global positioning capabilities. The satellite constellation consists of the nominal 24-satellite constellation. The satellites are positioned in six earth-centred orbital planes with four satellites in each plane. The nominal orbital period of a GPS satellite is one half of a sidereal day or 11h 58min. The orbital radius is approximately 26600km. This satellite constellation provides a 24hour global navigation and time determination capability The orbital plane locations with respect to the earth are defined by the longitude of the ascending node,while the location of the satellite with in the orbital plane is defined by the mean anomaly. Operational control segment(OCS) • The OCS has the responsibility for maintaining the satellites and their proper functioning. • The control segment comprised of three components: the master control station the monitor station, the ground antennas • The monitor stations passively track the GPS satellites as they pass overhead by making pseudo-range and delta-range measurements. • Handheld GPS device: Typically used for mapping small areas, these GPS receivers can store contour maps, plot your route, mark points of interest etc. Conclusion • Premium Dealers are a select number of stores that have access to the full Memory-Map range. These stores have been specially selected for their knowledge of MemoryMap and GPS navigation, they carry the largest range of Memory Map on the high street (or out of town) and you'll be able to get hands on with Memory-Map via the in store PC and receive expert advice from extremely knowledgeable staff on which products are right for your needs. This Presentation is presented By G.VENKATESH (08HE5A0112) Y.LOKANADHAM (08HE5A0120)