1. GPS – Global Positioning System Nick Fishel MAT 606

2. How does GPS Work? 27 Satellites orbit the earth At any point at any time at least 4 can be seen. Developed by the Army now available to the public A GPS receiver uses radio signals to figure out location. - Trilateration

3. What is Trilateration? The idea that three circles will intersect at one point Satellites A - 256 miles from Boise B – 543 miles from Indianapolis C – 130 miles from LA Boise Indianapolis LA

4. Calculating where you are GPS Receiver needs to know 2 things The location of the satellites Distance between you and the satellites Uses synchronized clocks and radio signals Once the receiver makes this calculation, it can tell you the latitude, longitude and altitude (or some similar measurement) of its current position. To make the navigation more user-friendly, most receivers plug this raw data into map files stored in memory

5. GPS Can Tell You How far you've traveled (odometer) How long you've been traveling Your current speed (speedometer) Your average speed A "bread crumb" trail showing you exactly where you have traveled on the map The estimated time of arrival at your destination if you maintain your current speed

6. Where They Can Go In your car Connected to your PDA Individual Receivers Cellphones

7. Big Names in GPS Garmin Magellan Etrex Legend GPS Receiver SporTrak Color

8. Questions