Vehicle navigation using differential GPS

It is pointed out that GPS (Global Positioning System), like any other means of navigation, has its own error sources that are unique to its implementation. The implementation of differential GPS deals with a process whereby most of these errors can be minimized, if not eliminated, thus improving the overall accuracy of GPS to a level of a few meters. These test results are presented, and applications of differential GPS are discussed. It is concluded that, in many applications where GPS navigation system and bidirectional data links exist and are in place, the cost of implementing differential GPS is minimal