针对实时动态PPP中常常会遇到卫星信号中断或大部分卫星发生周跳而导致重新初始化的问题,可以将GNSS信号短时间中断看作是全部卫星发生周跳,通过研究Doppler观测值在快速重新初始化中的观测模型,进而提出联合伪距、相位、Doppler观测值及电离层延迟变化约束信息的数学模型,对于发生周跳的卫星,通过将周跳参数固定为整数以实现动态PPP快速重新初始化。根据实际算例,从多个角度进行统计分析表明引入Doppler观测值能够提高周跳修复的成功率,从而加快PPP快速重新初始化的过程。
Aiming at solving the problem of re-initialization caused by loss of lock in signal tracking or cycle slips in most of the satellites in real time kinematic PPP,temporary data gaps due to loss-of-lock may be considered as cycle slips of phase observations in all satellites tracked,the observation model of Doppler observation in the instantaneous re-initialization process is investigated,and mathematical model integrating pseudo-range,phase,Doppler observation and predicted ionospheric variation information is proposed.Through fixing the cycle slip parameter of cycle slip occurred satellites to integers,instantaneous re-initialization in real time kinematic PPP is realized.Based on numerical experiment,statistical analysis from multiple aspects reveals that introduction of Doppler observations could improve the success rate of cycle slip fixing,thus accelerating the process of instantaneous re-initialization in real time kinematic PPP.