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Welcome Students!. Where is Here?. N. W. E. S. 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. Latitude. Latitude: measures North or South of the Equator.
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Where is Here? N W E S
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.
Latitude Latitude: measures North or South of the Equator Latitude Lines run East West Latitude ~ Fatitude
Longitude Longitude: measures East or West of the Prime Meridian. Longitude lines run North South
What is GPS? Global Positioning System: A system that uses satellites to find a specific location on Earth. The location is given in longitude and latitude coordinates. You Are Here Hand held device used to communicate with the satellites.
Communication The GPS handheld receiver uses radio waves to talk to the satellite and find its location.
Trilateration Trilateration: using a set of 3 points or more to find the location of an unknown point.
Ft. Collins Satellite 1 Satellite 2 Longmont Boulder Denver Satellite 3
? ? Minnesota Colorado Missouri
How far??? GPS receivers use time to know how far away the satellites are. Example: Lightening and Thunder in a storm.
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!
Bringing it all together Latitude and Longitude let us know exactly where we are. GPS can be used to tell us where we are on Earth GPS uses trilateration to find a location GPS uses time to find distance Why is GPS so important???
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