welcome students!
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
Welcome Students!
Where is Here?N
E
S
W
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 ~ Fatitude
Latitude Lines run East West
Latitude: measures North or South of the Equator
Longitude lines run North South
Longitude: measures East or West of the Prime Meridian.
What is GPS?
Hand held device used to communicate
with the satellites.
The location is given in
longitude and latitude
coordinates.
You Are
Here
CommunicationThe GPS handheld
receiver uses radio waves to talk to the satellite and find its location.
Trilateration: using a set of 3 points or more
to find the location of an unknown point.
Satellite 1
Satellite 3
Satellite 2
Longmont
Ft. Collins
DenverBoulder
State 3 =
Satellite 1 16 cm
Satellite 2 13 cm
Satellite 3 13.4 cm
Satellite 4 10.5 cm
State 1 =
Satellite 1 13 cm
Satellite 2 11 cm
Satellite 3 15 cm
Satellite 4 13.7 cm
State 2 =
Satellite 1 11 cm
Satellite 2 17.2 cm
Satellite 3 9 cm
Satellite 4 16 cm
?
?
ColoradoMinnesota 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
GPS can be used to tell us where we are on Earth
Why is GPS so important???
GPS uses time to find distance
Latitude and Longitude let us know exactly where we are.
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