1. Global Positioning System: An Overview

2. Parts of GPS system -Satellites -Ground Stations -User GPS receivers

3. Purposes of GPS systems -Locating -Navigation -Tracking -Mapping -Timing

4. Timing -All 24 satellites in constellation have atomic clocks. (There are 30 in the constellation as of 2010) -Ground stations synchronize all of the clocks for extremely accurate timing. -Satellites also target themselves (Doppler Effect)

5. How do Global Positioning Systems Work? -24 active satellites in MEO (Medium Earth Orbit) -11, 000 miles in orbit -All satellites inclined 55 degrees from equator

6. Triangulation Satellites use triangulation to locate point and time - All locations need four satellites to effectively triangulate position

7. GPS Constellation

8. Triangulation BEST better good

9. Geometric Dilution of Precision and other Reasons for GPS system failure

10. How do I use the GPS Receiver?

11. Military Uses  Originally Developed by the US Department of Defense (current GPS system)  Clear military purposes  Navigating missiles and combat airplanes  Strategic positioning and location of troops Locating vehicles (ships, tanks, ATV’s)

12. Commercial (Civilian) Uses  Guiding our cars, trains, trucks, boats, ships, and airplanes  Police use  Hikers *  Organizations and Companies  Farmers  Many more

13. Scientific Uses for GPS  Geoscience- -Seismology -Volcanology -Meteorology -Geodesy

14. Scientific Uses for GPS (cont’d)  Surveyors  Zoologists  Engineers  NASA  Astronomers

15. Future Uses  Backpacks are currently being developed to guide the blind through intricacies of major cities  Virtually unlimited possibilities  GIS systems-tracking data

16. Future Uses

18. Geocaching -An adventure for hikers using GPS systems -Started on May 3, 2000 by Dave Ulmer -Posted the event on a GPS internet users group

19. Geocaching -Beaver Creek, Oregon -N 45 17.460 W 122 24.800 -Basic idea: hide a container in the woods and note coordinates using only GPS unit

20. “Take some stuff, leave some stuff”  Originally called, “The Great American Stash Hunt”  Mike Teague was the first to find “stash” left by Ulmer

21. Geocaching  Slashdot- on-line magazine for techies reported the event on Sept. 25, 2000  New York Times that October  Taken off and now is global phenomena  Geocaching.com

22. Benefits of GPS in the Classroom  Geography lessons-map the school/area  Mathematics  Social Studies-how areas have changed over time  Community Service

23. Benefits of GPS in the Classroom  What are some benefits you see for the classroom?  Get into groups and discuss options.  Be thinking of ideas during next lesson.  You will deliver your ideas to the class when we return

24. LET’S GO!!!!