Rabu, 2007 Agustus 15
GPS known as Global Positioning System is currently the only fully functional Global Navigation Satellite System (GNSS). More than two dozens GPS satellites are in Medium Earth Orbit (MEO), transmitting signals allowing GPS receivers to determine the receiver's location, speed and direction.
Since its first experimental satellite was launched in 1978, GPS has become an indispensable aid to navigation around the world, and an important tool for map-making and land surveying. GPS also provides a precise time reference used in many applications including scientific study of earthquakes, and synchronization of telecommunications networks.
The principle behind GPS is that receivers are able to use the technique of “Trilateration” to calculate their coordinates by measuring the time taken for signals from various GPS satellites to reach them.
The GPS software will account for any irregularities in the signal strength and clock.
Differences between itself and the GPS satellite network by using signals from four separate satellites to improve accuracy.
Usually the coordinates are then used to locate the GPS device on a map, which is either displayed to the user or used as a basis for calculating routes, navigation, or as input into mapping programs. For example, specific coordinates can be stored as waypoints allowing the user to retrace their steps by calculating the direction and distance to each waypoint that they have stored.
- Outdoor activities E.g.: hiking etc
- Vehicle Tracking System
- Environment E.g.: detection of birds’ migrations
- And many more…