Multi-GNSS real-time precise clock estimation considering the correction of inter-satellite code biases
Multi-GNSS real-time precise clock estimation considering the correction of inter-satellite code biases
复制标题
DOI：
10.1007/s10291-020-01065-z
复制
发表时间：
2021-01
期刊：
影响因子：
4.9
通讯作者：
Liang Chen;Min Li;Ying Zhao;Zhigang Hu;Fu Zheng;C. Shi
中科院分区：
文献类型：
--
作者：
Liang Chen;Min Li;Ying Zhao;Zhigang Hu;Fu Zheng;C. Shi
由于主要与芯片形状畸变有关的原因，全球导航卫星系统（GNSS）的观测结果受到接收机相关偏差的破坏。这些通常在长期内是稳定的，尽管数值上因信号频率、卫星系统和接收机制造商而异。基于混合差分模型，结合无差分伪距和差分载波相位观测，提出了一种考虑星间码偏校正的多gnss实时精确时钟估计模型。引入了依赖于接收机的预估ISCB校正，在很大程度上校正了接收机间、卫星间和系统间的偏差。然后将估计参数的数量减少到可管理的水平，以便实时估计。与后处理数据的比较表明，与未差分、年代差分和未校正偏差的混合差分模型相比，校正偏差模型可以大大降低精确时钟偏移系统偏差，特别是对于GLONASS和北斗系统。测试结果表明，GLONASS系统的均方根数据减少率提高了96%，北斗系统提高了78%，GPS和伽利略系统提高了40%。
For reasons mostly related to chip shape distortions, global navigation satellite system (GNSS) observations are corrupted by receiver-dependent biases. These are often stable in the long term, though numerically different depending on the signal frequency, satellite system and receiver manufacturer. Based on the mixed-differenced model combining undifferenced pseudorange with epoch-differenced carrier phase observations, we present a multi-GNSS real-time precise clock estimation model considering correction of inter-satellite code biases (ISCBs). Pre-estimated receiver-dependent ISCB corrections are introduced to correct the inter-receiver, inter-satellite and inter-system biases largely. Then the number of estimated parameters is reduced to a manageable level for real-time estimation. Comparisons with post-processed data show that compared to undifferenced, epoch-differenced and non-bias-corrected mixed-differenced models, the proposed bias-corrected model can greatly reduce the precise clock offset systematic biases, especially for GLONASS and BeiDou. The test results show the root mean square data reductions are improved by up to 96% for GLONASS, 78% for BeiDou and 40% for GPS and Galileo.