| Popis: |
The single-difference FCB is applied to the ambiguity resolution of precise point position,which can improve the positioning accuracy and speed up the convergence.However,due to the earth block,one satellite cannot form common views with other satellites,which means one reference satellite cannot get all the single-difference FCB.If single-difference FCB of multiple reference satellites is broadcast as a supplement,the burden of data transmission will be increased.Considering the availability and data volume,this paper proposes an improved FCB generation method.Based on the principle of differential transfer,it converts the single-difference FCB's of different reference satellites into a common one.Then it uses the robust estimation based on the GPHASE initial value to merge the converted FCB.In this paper,15 days data from IGS monitoring network are selected to generate the improved FCB and the fixed solution PPP is implemented.The experimental results show that the improved single-difference FCB of one reference satellite can meet the application requirements.Stability and availability of the improved FCB is better than that of traditional single-difference FCB,and the difference compared with existing FCB product is less than 0.04 cycle.Using the improved FCB,users can achieve a fixed solution PPP with a horizontal accuracy better than 1 cm and a vertical accuracy better than 2 cm in static mode.The kinematic PPP can achieve the 3D positioning accuracy within 5 cm in about 15 minutes. |
