PPP-B2b服务钟差常数偏差特性及对定位的影响分析

Characterization of the constant bias from the clock offset of the PPP-B2b service and the impact on positioning

针对PPP-B2b服务钟差产品包含相比于其他实时钟差产品更大的钟差常数偏差,可能会影响精密单点定位收敛时间的问题,该文利用非差法解算接收机信号失真偏差时钟差常数偏差和SDB相互耦合的关系,对钟差常数偏差进行分离,并分析了PPP-B2b服务钟差中常数偏差的特性及其对定位的影响。发现此项偏差随卫星弧段不同变化,不同弧段之间的差异能达到3.5 ns,进一步在伪距观测量中改正此项偏差可分别使BDS和GPS精密单点定位收敛时间减少55.4%和53.5%。上述实验结果表明,PPP-B2b服务中钟差常数偏差在不同弧段间存在较大差异,并且显著影响定位收敛速度。

According to PPP-B2b service clock offset containing a larger constant bias than other real-time clock offset products,which may affect the convergence time of precision single-point positioning,this paper separates the clock constant bias according to the coupling relationship between the Signal Distortion Bias(SDB)and clock constant bias,and analyzes the characteristics of the clock constant bias in PPP-B2b service clock offset and the effect for positioning.It is found that the bias varies with different arcs of the satellite,and the difference between different arcs can reach 3.5 ns.Further correcting the bias in the pseudo-range observation can reduce the convergence time of BDS and GPS precise point positioning by 55.4%and 53.5%,respectively.The above results show that the clock constant bias in PPP-B2b service has great differences among different arcs,and significantly affects the positioning convergence speed.