Research On GPS Carrier Phase Positioning Algorithm

As the most advanced navigation and positioning system in the world, GPS(Global Positioning System) has become popularized in the world, it increasingly shows the great advantages of satellite navigation and become a major role in the economy and the military field. On the one hand, GPS requires navigation and positioning data available for ground, air and sea forces and launching missile and guidance in real time because that the military needs to improve the positioning accuracy continuously. On the other hand, GPS is widely used in cars, mobile phones and other civilian areas. The need of the positioning accuracy is gradually rised , thus the positioning algorithm of GPS is of great significance.Among all the different GPS methods, the pseudo method is simple, but the accuracy is low. Meanwhile, the carrier phase method is with high accuracy, but the calculation is complex and takes a long time. In the carrier phase method, the solution of the integer cycle ambiguity is the key to determine the accuracy of the carrier phase method.This paper mainly analyzes the GPS carrier phase method and proposes a relevant algorithm according to the results of computer simulation. Firstly, it introduces the overview of GPS system and research status in GPS positioning method, then it introduces the composition of GPS, GPS signal structure, coordinate system and time system in which GPS positioning. Secondly, it studies the error which affect in GPS positioning accuracy and some methods and measures which can reduce error. It focuses on studying the various GPS positioning algorithm, discusses differential positioning algotithm in measuing pseudo-code and carrier phase respectively, and then it proposes a five-point solution algorithms which do not need to solute the whole cycle ambiguity, and significantly improves the speed of the algorithm and gives simulation of the algorithm at the same time. Again it studies ambiguity solving theory at the carrier phase measurement, in connection with base stations and receivers for long baseline, a triangular reference network which combined with LAMBDA (least square ambiguity decorrelation adjustment method) is proposed in a new single epoch ambiguity resolution algorithm. The algorithm requires only one epoch, regardless of cycle slip detection and repair and is used in the descend triangle to decrease the search range, thereby increasing the speed of the algorithm and improving the accuracy of positioning, and then given practical examples of the simulation. Finally, the paper sums up the significance of this study and the work content, and the further research work.