The study of BDS RTK algorithm based on zero-combined observations and ionosphere constraints.

Abstract A new BeiDou Navigation Satellite System (BDS) Real Time Kinematic (RTK) algorithm based on zero-combined observations and ionosphere constraints is developed in this study. When applying the zero-combined observations, the Double-Differenced (DD) ionospheric residuals are estimated as unknown parameters by adding the a priori information, i.e., the spatial and temporal ionosphere constraints. An experimental dataset was used to perform the validation and analysis. The results show that the proposed algorithm can precisely correct the DD atmosphere residuals, not only for the short baselines but also for the long baselines. Besides, the positioning results reveal much smaller noise and are more stable than the method of utilizing ionosphere-free combinations. A positioning accuracy of about 1–2 cm can be achieved with the BDS RTK for the baseline of 100 km. [ABSTRACT FROM AUTHOR]