Model Comparison and Performance Analysis of Triple-frequency BDS Precise Point Positioning

Three kinds of triple-frequency precise point positioning (PPP) models containing two ionosphere-free combined models, the model of triple ionosphere-free linear combination and uncombined model are achieved based on Trip software. Triple-frequency PPP models and traditional dual-frequency ionosphere-free combined PPP model are tested by BDS data from 12 stations of Crustal Movement Obervation Network of China. The results show that for most stations, daily static positioning accuracy is better than 1 cm in horizontal, 2 cm in vertical, and is better than 4 cm in horizontal and 6 cm in vertical for kinematic positioning accuracy. The average convergence time for each triple-frequency is about 120 min for static case and about 180 min for kinematic case. Comparing with traditional dual-frequency PPP models, triple-frequency PPP models can obtain higher accuracy, to be specific, root mean square (RMS) in daily static solutions of triple-frequency uncombined PPP models can be improved by 36.1% and 6.3% horizontally and vertically, and RMS in daily kinematic solutions can be improved by 9.1% and 6.3% horizontally and vertically.