Abstract: Network RTK,at present,is one of the important means to realize high precision and real-time dynamic positioning,while the key problem of high precision positioning of network RTK is the real-time, fast and accurate fix of the integer ambiguity between reference stations.For a wide scale network RTK, because the distance between reference stations has increased and the ionospheric delay error、the troposphere delay error and satellite orbit error have a low correlation that leads to integer ambiguity in the reference stations can not solve quickly and accurately,therefore this paper presents a method that integer ambiguity algorithm in a wide scale network RTK reference stations.Firstly,this algorithm takes advantage of L1、L2 carrier phase observations and P1、P2 pseudorange observations to calculate the double difference wide lane ambiguity between reference stations,and then to solve double difference troposphere delay by combining Saastamoinen model with Chao mapping function model,at the same time,the thesis takes the double difference wide lane ambiguity regard as constraint condition of L1、L2 double difference the carrier phase integer ambiguity so as to make sure L1、L2 double difference carrier phase integer ambiguity.The experiment was carried out by using the measured data of CORS,at the same time,the experimental results of this paper are compared with the results of GAMIT software show that the algorithm can achieve single epoch double difference carrier phase fixed integer ambiguity stably and accurately.

Key words: large scale, network RTK, reference station, integer ambiguity, tropospheric delay