1. Global Positioning Systems GPS Units: Development to Modern Uses

2. Getting to Know Your GPS Notes Notes Notes Draw a Diagram in your notes Label each of the buttons Label each button with one function -What do they do?

3. What is GPS? Notes Notes Notes Satellite based navigation system -satellites orbit Earth twice a day U.S. Department of Defense in the early 1980’s -first satellite launched in 1978 NAVSTAR -official governmental name for GPS

4. How Does a GPS Work? Satellites transmit data to Earth receivers -You are holding a receiver! Triangulation used to pin point location -very similar to our method on the map! Notes Notes Notes What really happens… 1. Receiver compares time signal from when it was transmitted to when it was received 2. Time difference tells unit how far you are from the satellite 3. Distance relayed from several other satellites to receiver configures your position!

5. Satellites 24 orbiting 12000 miles above us Travel at speeds up to 7000 mph The more you use, the more accurate your data Powered by solar energy with backup battery -in case of solar eclipse! Stays on path using rocket boosters to adjust course

6. Would Your GPS Ever Let YOU Down? Clock errors Atmosphere Solar Flares Radiation Altitude Large buildings Number of Satellites Age of Unit

7. Military Uses Navigation Target tracking Missile and projectile guidance Search and Rescue Reconnaissance and Map Creation The GPS satellites also carry a set of nuclear detonation detectors

8. Scientific Uses Notes Notes Notes Surveying -accurate data much faster Mapping -accurate elevation, lat. & long. quickly Emergency Management -receiver in phones so can be located by dispatcher Monitoring Tectonics -measure actual distance moved during an earthquake Uniform time -transmits data via time measurements, very precise

9. Prices…Can Everyone Get One? Civilian ranges from $100 to $500 Survey ranges from $1000 to $5000 Military Who knows! * You could spend as much as you wanted!

10. Review…What Have You Learned?