Tu Rui, Zhang Pengfei, Zhang Rui, Liu Jinhai, Lu Xiaochun
National Time Service Center, Chinese Academy of Sciences, Shu Yuan Road, Xi'an 710600, China.
Key Laboratory of Precision Navigation and Timing Technology, Chinese Academy of Sciences, Shu Yuan Road, Xi'an 710600, China.
Sensors (Basel). 2018 Mar 29;18(4):1017. doi: 10.3390/s18041017.
This study proposes two models for precise time transfer using the BeiDou Navigation Satellite System triple-frequency signals: ionosphere-free (IF) combined precise point positioning (PPP) model with two dual-frequency combinations (IF-PPP1) and ionosphere-free combined PPP model with a single triple-frequency combination (IF-PPP2). A dataset with a short baseline (with a common external time frequency) and a long baseline are used for performance assessments. The results show that IF-PPP1 and IF-PPP2 models can both be used for precise time transfer using BeiDou Navigation Satellite System (BDS) triple-frequency signals, and the accuracy and stability of time transfer is the same in both cases, except for a constant system bias caused by the hardware delay of different frequencies, which can be removed by the parameter estimation and prediction with long time datasets or by a priori calibration.
具有两种双频组合的无电离层（IF）组合精密单点定位（PPP）模型（IF-PPP1）和具有单个三频组合的无电离层组合PPP模型（IF-PPP2）。使用一个短基线（具有共同外部时间频率）和一个长基线的数据集进行性能评估。结果表明，IF-PPP1和IF-PPP2模型均可用于利用北斗导航卫星系统（BDS）三频信号进行精确时间传递，并且两种情况下时间传递的精度和稳定性相同，不同频率硬件延迟导致的恒定系统偏差除外，该偏差可通过长时间数据集的参数估计和预测或先验校准消除。
