Principle And Algorithm Research For GPS Network RTK

GPS network RTK positioning is a kind of high precise GPS positioning technique whichhas developed in recent years. It forms a GPS network from multiple reference stations andthen eliminates or mitigates the influence of GPS observation errors on roving receiver, basedon the basic principle and techniques of WADGPS and LADGPS with multiple referencestations so as to increase the distance between reference stations and roving receivers andenhance the accuracy of GPS real time kinematic positioning. Compared with conventionalRTK, this technique has many advantages like wider action area, more accurate, more reliablepositioning etc. It can also provide RTK positioning in centimeter accuracy for users. On thebase of the principle and error sources of GPS network RTK system, this article mainlydiscusses the correct number generation algorithm of the base station and mobile station. Themain contents of study are as following:1. The principle and ingredients of GPS network RTK system. This article mainlyintroduction the basic concepts, principles and methods of GPS network RTK system, as wellas the key technologies for the exploration and its advantages were introduced.2. The analysis of error source of Network RTK system, as the analysis and modeling ofsystem errors is introduced as one of the most important part of Network RTK technique, soon the base of technique of GPS network RTK, the main error sources, primarily theionosphere errors, troposphere errors, orbit errors and multipath errors, etc. are underdiscussion. It is given that the relations between elevation and troposphere delay ofobservations. In addition, the factors such as temperature, air pressure, water vapor, differenceof altitude and model, can also influence on single-difference troposphere delay. In lastDifferential equations and observation linear combinations were introduced.3. The positioning algorithm research of Network RTK. It mainly introduces linearcombination method, interpolation method and condition Adjustment method; According toGao Xing Wei's combined bias concept of base station and mobile station, This paper presentsthe mathematical model of interpolation method of combined bias and given formulas. It caneliminate the combined bias of rover stations of network RTK very good4. With the "Qingdao Gulf Bridge GPS network data", this paper use the integrated error interpolation algorithm to calculate the coordinates of the mobile station, and realized thealgorithm. The results of the analysis verify the accuracy and reliability of interpolationalgorithm of combined bias.