附加原子钟物理模型的PPP时间传递算法

传统精密单点定位(PPP)时间传递算法通常把接收机钟差当作相互独立的白噪声逐历元进行估计,而忽略了钟差参数历元间的相关性。针对这一问题,本文提出了一种附加原子钟物理模型的PPP时间传递算法。该算法通过利用Kalman滤波对高稳定度的原子钟钟差进行建模,拓展传统PPP时间传递模型中的接收机钟差参数,并给出了Kalman滤波过程噪声协方差和初始状态向量的确定方法。试验结果表明:该算法可以有效避免传统算法时间传递结果需要一定收敛时间的问题,使解算结果更加符合原子钟的物理特性,能够显著提高时间传递结果的精度和稳定性,可将单站时间传递精度平均提高58%,站间时间传递精度平均提高51%。

A Time Transfer Algorithm of Precise Point Positioning with Additional Atomic Clock Physical Model

In the traditional time transfer algorithms of precise point positioning,the receiver clock offset is estimated epoch by epoch as independent white noise and the short-term correlation between the epoch of the atomic clock offset is ignored.In order to solve this problem,a time transfer algorithm of precise point positioning with additional atomic clock physical model is proposed.The receiver clock parameters are expanded in the traditional model of precise point positioning by using Kalman filter to model the clock errors of high stability atomic clock,and the method of determining the covariance matrices of process noise and the initial state vector of the Kalman filter is presented.Experimental results show that the proposed algorithm can effectively avoid the convergence process of the traditional precise point positioning algorithm,and the result of the algorithm is more consistent with the physical properties of the atomic clock,this algorithm can significantly improve the accuracy and stability of the time transfer results,the accuracy of time transfer results of single station can be increased on average by 58%,and the accuracy of time synchronization between stations can be improved on average by 51%.