2. Welcome Students!

3. Where is Here? N E S W

4. Earth’s Grid Equator: line that divides the Earth into Northern and Southern hemispheres. Prime Meridian: line that divides the Earth into Eastern and Western hemispheres.

5. Latitude Latitude ~ Fatitude Latitude Lines run East West Latitude: measures North or South of the Equator

6. Longitude Longitude lines run North South Longitude: measures East or West of the Prime Meridian.

7. What is GPS? Global Positioning System: A system that uses satellites to find a specific location on Earth. Hand held device used to communicate with the satellites. The location is given in longitude and latitude coordinates. You Are Here

8. Communication The GPS handheld receiver uses radio waves to talk to the satellite and find its location.

9. Trilateration Trilateration: using a set of 3 points or more to find the location of an unknown point.

10. Satellite 1 Satellite 3 Satellite 2 Longmont Ft. Collins DenverBoulder

11. State 3 = Satellite 116 cm Satellite 213 cm Satellite 313.4 cm Satellite 410.5 cm State 1 = Satellite 113 cm Satellite 211 cm Satellite 315 cm Satellite 413.7 cm State 2 = Satellite 111 cm Satellite 217.2 cm Satellite 39 cm Satellite 416 cm ? ? ColoradoMinnesotaMissouri

12. How far??? GPS receivers use time to know how far away the satellites are. Example: Lightening and Thunder in a storm.

14. How Far? GPS satellites measure distance using the speed of light Light travels at 186,000 miles per second If it takes a signal 10 Seconds to travel from a GPS receiver to a GPS satellite, how far apart are they? 10 seconds x 186,000 miles per second = 1,860,000 miles The sun is 93,000,000 miles away…how long do you think it takes the light from the sun to reach Earth??? 93,000,000 ÷ 186,000 = 8 minutes!

15. Bringing it all together GPS can be used to tell us where we are on Earth Why is GPS so important??? GPS uses time to find distance GPS uses trilateration to find a location Latitude and Longitude let us know exactly where we are.

16. CarBoat Airplane Tracking Packages

17. GeocachingGeocaching