Research Of Algorithm And Simulation Of Differential Global Positioning System

The precision of traditional GPS standard positioning is not satisfied, it is limited within ±25 meter(2drms) even though SA has been canceled. Differential Global Positioning System (DGPS) can improve the precision greatly, reach a precision of the meter order, even the centimeter order. So, DGPS have developed greatly and been applied widely.DGPS can be sorted to 4 types: Position differential mode, pseudo-range differential mode, carrier phase differential mode and wide area differential mode. These four differential modes work on the same principle. That is, the base station transmits differential corrections; the remote station receives the corrections and corrects its measurement for precise positioning result. What is different is the concrete content of the correction, which makes different in the precision of positioning. In terms of the actual need, the position differential mode is seldom used because of its poor positioning precision. What is used common is the pseudo-range differential mode, the carrier phase differential mode and wide area differential mode deployed by nation. This paper will do detailed research on the pseudo-range differential mode and the carrier phase differential mode.The algorithm of the differential correction in DGPS base station is a critical technical problem in DGPS. From the easiest position differential technique to be dealt with using Kalman Filtering, then to model errors in wide area DGPS, the algorithm of differential correction has been researched continually. But there is few data introducing algorithms of DGPS differential correction. In this paper, three algorithms now widely used are researched detailedly, including computing differential correction using pseudo-range measurement, computing differential correction using phase smoothed pseudo-range measurement and computing differential correction using the combination...