In order for a GPS system to find a target, that target must emit a radio signal to allow the satellites to pinpoint its position. Manufacturers of GPS devices advertise mapping, displays and routes, but the accuracy of GPS depends on factors like movement of the device, weather, satellite positions and signal noise.
Function
The GPS system works by receiving a signal from the GPS device and then using three satellites to triangulate the position. By factoring in the time difference from each satellite, the GPS system can map out a geographic location.
Errors
Errors in accuracy can be attributed to mountainous terrain, trees and tall buildings. However, noise, static and interference can also contribute to errors.
Accuracy
Garmin, a manufacturer of GPS receivers, puts the accuracy of their devices within 15 meters on average. With the addition of the Wide Area Augmentation System (WAAS) the accuracy can be improved to within three meters on average.
DGPS
Differential Global Positioning Satellites use a fixed position on the ground to help pinpoint a GPS device. Any difference in the fixed position and satellites is adjusted for, resulting in better accuracy.
WAAS
The Wide Area Augmentation System works the same way as DGPS but covers the entire continental U.S. and parts of Alaska.
Tags: Area Augmentation, Area Augmentation System, Augmentation System, fixed position, meters average, Wide Area