A multi-epoch algorithm for GPS/BDS single frequency precise point positioning

With the rapid and vigorous development of Internet of Things (IoT), many kinds of IoT applications will more highly depend on satellite positioning system in the future. Merely single system cannot provide better navigation service, so we integrate Global Positioning System (GPS) with Beidou Satellite Navigation System (BDS) for single frequency precise point positioning, and hope to achieve the purpose of real-time positioning. To integrate GPS with BDS well, we use Helmert variance component estimation to adjust the weighting of GPS and BDS. About the elimination of measurement errors, we use the Ultra-Rapid ephemeris provided by International GNSS Service (IGS) for correcting satellite orbit errors and satellite clock errors of GPS. IGS also provide broadcast ephemeris for BDS and was used here for correcting satellite orbit errors and satellite clock errors. The Global Ionospheric Map provided by IGS was adopted for correcting ionospheric delay errors. Moreover, UNB3m model was chosen for correcting tropospheric delay errors. On the positioning algorithm, the concept of adaptive multi-epoch algorithm was proposed. The positioning accuracy and the operation time were investigated. Comparing with the single-epoch algorithm, the experimental results show that adaptive multi-epoch algorithm can substantially enhance the precision of static positioning with reasonable cost of the operation time.