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GPS THE GLOBAL POSITIONING SYSTEM. What is GPS?. GPS is a satellite-based radio navigation system that allows anyone anywhere on the planet to determine their 3D position with great accuracy and precision. Who maintains GPS?. Department of Defense (DOD) – NAVSTAR Russia GLONASS
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What is GPS? • GPS is a satellite-based radio navigation system that allows anyone anywhere on the planet to determine their 3D position with great accuracy and precision.
Who maintains GPS? • Department of Defense (DOD) – • NAVSTAR • Russia • GLONASS • European Economic Community • System Under development
The system is composed of three segments • Space - The orbiting satellites • Control - The monitoring stations on earth • User - The GPS units such as you will use today.
When was GPS first used? • Sputnik…1957 • TRANSIT…1960’s • NAVSTAR…1970’s
How many satellites make up a GPS? • 27 at the current time • 24 to maintain a system Your GPS receiver must track at least 3 satellites to give you an accurate position location. *The word “tracking” must appear on the screen
Who uses GPS? • Government • Military • Agencies - Conservation, Weather, Rescue • Industry • Transportation • Fishing • Agriculture • General Public • Recreation • Emergency / Security Reasons • Health Related Reasons
How does GPS Work? • Each GPS satellite transmits an accurate position and time signal. • The user’s receiver measures the time delay for the signal to reach the receiver. • Measurements collected from 4 satellites are processed to solve for the 3D position, velocity and time.
Your Task Outside 1) Get a locked reading on your unit. 2) Chose a direction either east-west, or north-south. 3) Walk along the direction vector until the reading on your unit changes.
What you discovered outside. 1) Did you all get the exact same reading? 2) How did you know your direction? 3) How many paces until the reading on your unit changed?