Global Positioning Systems

1. Global Positioning Systems Presented by: Wesley D. Fulbright

2. What is GPS? • A worldwide radio-navigation formed from a constellation of 24 satellites and ground stations • These days GPS is finding its way into cars, boats, planes, construction equipment, movie making gear, farm machinery, even laptop computers. • Used to calculate positions accurate to a couple of meters

3. How GPS Works… • Use satellites as reference points – use 3 satellites to “triangulate” position • The GPS receiver measures distance by using the travel time of radio signals • Timing is configured by using atomic clocks • Using a 4th satellite ensures the perfect time – if timing is off by a thousandth of a second it can mean almost 200 miles of error

4. Where are the Ground Stations… • Hawaii • Ascension Island • Diego Garcia • Kwajalein • Colorado Springs

5. Scientists Farmers Soldiers Pilots Surveyors Hikers Delivery Drivers Sailors Dispatchers Lumberjacks Fire Fighters Who uses GPS?

6. Types of Errors • Passing through the different layers of the atmosphere slows the wave down • Local obstructions on the ground • Atomic clock errors • Using satellites that are close together

7. The End Reference: www.trimble.com