Research And Realization On The Algorithm Of GPS/BDS Real-time Kinematic Relative Positioning

With the doing business and providing serve of BeiDou Navigation Satellite System,the LBS applied research based on BDS is carried out rapidly.It is widely used in traffic safety?marine fishery?surveying and mapping?Smart City-and precision agriculture and so on.There are many advantages to merge multi-GNSS for positioning,The algorithm of GPS/BDS real-time kinematic relative positioning is researched in depth and implemented using program in the paper.The algorithm of GPS/BDS real-time kinematic relative positioning is researched in depth based on GPS and BDS real-time kinematic relative positioning.Firstly,the data pre-processing is conducted,the time and space reference frame of GPS and BDS is unified.The cycle slip and gross error are detected in observation data combinationally used the method of difference of triple difference,the method of MW combination and geometry-free phase combination which is verified effectively in the simulation experiment of cycle slips detection.The dual-differential observation model is adoptedin the functional model of GPS/BDS kinematic relative positioning merging the observation data of GPS and BDS.The random model is estimated using the function of elevating angle and the Helmert variance components estimation sufficiently considering the error characteristics of the inter-system observation.the ambiguityparameters are estimated in the superimposed nomal equations by epochs based on the ·least square method of eliminating parameter.The method of LAMBDA is applied for fixing the integer ambiguities and get the precise value of position.The changing condition of RATIO and the ratio of successfully fixed ambiguities are counted in the experiment which indicate that the fixed ambiguities are reliable.The performance of GPS/BDS is superior to the only GPS or BDS in either the time of initialization or the accuracy of positioning,the time of initialization is so short that the cm-level positioning result is gotten in onlt 1s.The experimental result indicate that the program of the GPS/BDS real-time kinematic relative positioning is available and the positioning precision reaches cm-level.