Velocity Determination Model and its Accuracy Analysis with Multi GNSS

Based on the principle of velocity determiantion with doppler observations, the mathematic model of velocity determination with multiGNSS is introduced and then the accuracy and performance of velocity determination with raw doppler observations,derived doppler observations and the combined observations are tested and analysed.The results show that the combination of multiGNSS can improve the accucary of velocity significantly with raw doppler observations and derived doppler observations.The combination of raw doppler observations and derived doppler observation with single system also can improve accuacy of velocity,but when we use multiGNSS,it does not work very well for lack of rigorous stochastic model.