Abstract:Ambiguity resolution based on conventional ionosphereweighted model usually needs prior information about ionoshperic delay.A new ambiguity resolution for network RTK based on improved ionosphereweighted model is proposed for the situation without prior information.Firstly,the ionospheric pseudoobservations and stochastic model are constructed through carriersmoothed code.Then,the Kalman filter mode based on ionosphereweighted function is established.at last,the adaptive Kalman filter algorithm is introduced,so as to adjust parameters evaluation tolerance caused by model inaccuracy.Experiment shows that this new method possesses fast convergence and well stability.It is suitable to longrange network RTK,particularly to the satellites with 20°or more elevation angle.