Research On Technology Of GPS Carrier Phase Positioning

Global position system (GPS) is a real time, all climate, global navigation and positioning system base on satellites. It has a lot of applications in many fields in mapping, navigation, communication, economy and national defence and so on.The GPS position based on carrier phase measurement is produced and developed for the exaltation of positioning accuracy. Differential relative positioning of GPS (DGPS) is gradually perfected. On the basic of above, this, to a great extent, enhanced the precision of GPS positioning and widened the application range of GPS. In this paper, we systematically discuss the theory and method of the technique of carrier phase and differential GPS.Firstly, this paper introduced the components and features of GPS, the form of satellite signal and how to compute the position of satellite. We discussed the basic observation mathematic model of GPS. Two basic observation functions are introduced in detail. We analyzed infections of various errors, and simulated the single positioning through the two basic observation values; then we discussed the working principle and the mathematic model of differential positioning technology with GPS carrier phase in real time, and gived three models of linear combination of carrier phase, and simulate its performance. Integer ambiguity resolution is described mainly at last. We analyzed the diversified methods of ambiguity resolution under the dynamic and the static condition respectively. The LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) was emphasized, and the resolving step and flow chart of this method were offered. We could clearly see that it improves precise and real time of positioning by simulating and analyzing the results of the float and the fixed solutions. It is meaningful to deal with the real time, dynamic and precise positioning.