1. Advantages
1.1. easily accessible
1.1.1. Only a GPS receiver is needed
1.2. High speed
1.2.1. information generated and transmitted at a high speed
1.3. travelling convenience
1.3.1. improving the instant mapping technology
1.4. Helpful in emergency
1.4.1. having panic buttons calling for help
1.4.2. Easily be found if you suffer from an accident
1.5. Memory-based system
1.5.1. Turn-by-turn directions
1.5.1.1. GPS devices saved your route automatically that you don't need to find your way back home
1.6. Nearby area searching
1.6.1. Hotels
1.6.2. Oil stations
1.6.3. Hospitals
1.6.4. Govermnent offices
2. Disadvantages
2.1. Reception
2.1.1. The services are only available only if having clear access
2.1.2. Show you nothing or generate incorrect information when it's not accessing well
2.2. Accuracy
2.2.1. Sometimes it may not be the most updated
2.2.1.1. Properly direct you onto a road that is closed
2.3. Distracting drivers
2.3.1. Pay more attention to the GPS devices instead of the road
2.3.1.1. Accident occurs
2.4. Need well maintenance
2.4.1. The ststem will easily break down
2.4.1.1. Huge maintenance fees
2.5. Cost
2.5.1. Get what you pay for
2.5.1.1. Which can be really expensive
2.6. Battery Life
2.6.1. Drain quickly
2.6.1.1. Not plugged into power source
2.6.1.1.1. Can only last for one hour
3. Application
3.1. Geotagging
3.1.1. Applying location coordinates to digital objects (for purposes ,e.g.map overlays)
3.2. Tracking system
3.2.1. locating a vehicle, person, or pet
3.3. Automotive navigation system
3.3.1. Acquiring position data to locate the user on a road in the unit's map
3.4. Map-making
3.4.1. Civilian and military cartographers use it extensively
3.5. Tectonics
3.5.1. Direct fault motion measurement in earthquakes
3.6. Disaster relief
3.6.1. Depend upon GPS for location and timing capabilities
4. GPS (Global Positioning System)
4.1. Background
4.1.1. Space-based satellite navigation system
4.1.1.1. Location Information
4.1.1.2. Time Information
4.1.2. Operated by the United States government
4.1.2.1. Officially run in 1994
4.2. Principle
4.2.1. GPS satellites broadcast signals from the space to GPS receiver for calculating its three-dimensional location and current time
4.3. Segments
4.3.1. The Space
4.3.1.1. Transmit radio signal from satellites to the users
4.3.1.1.1. Managed by the Air Force
4.3.2. The Control
4.3.2.1. Global network ground of facilities
4.3.2.1.1. Track GPS satellites, monitor transmission,perform analysis
4.3.3. The User
4.3.3.1. GPS Precise Positioning Service
4.3.3.1.1. US government & Allied military users
4.3.3.2. GPS navigation devices
4.3.3.2.1. Civil, commercial and scientific users