PPP-B2b常数偏差实时改正后的多频单历元定位

Multi-frequency single epoch positioning method after real-time correction of PPP-B2b constant bias

针对PPP-B2b钟差产品存在纳秒级钟差常数偏差,且此常数偏差对PPP-B2b单历元定位存在较大影响的问题,该文通过分析PPP-B2b钟差及轨道精度确定了PPP-B2b常数偏差的存在,提出了一种利用卫星UDP产品构造北斗四频AFIF高精度观测值实时估计PPP-B2b常数偏差的算法,并进一步分析了估计值对于PPP-B2b单历元定位能力的提升。本文验证了卫星各弧段内不同测站所估计的常数偏差值的一致性,彼此之间差异约0.15ns,使用常数偏差估计值改正后,在E、N、U方向上的单历元定位可分别实现0.1802、0.1355和0.5207m的定位精度。上述实验结果表明,使用上述算法估计的常数偏差值相对于不加改正可大幅度提升PPP-B2b单历元定位精度,定位能力与精密星历精度相仿,实现了PPP-B2b实时单历元分米级定位。

Aiming at the existence of nanosecond clock error constant bias of PPP-B2b clock error product,which may cause large error in PPP-B2b single epoch positioning.,this paper determines the existence of PPP-B2b constant bias by analyzing PPP-B2b clock error and orbit accuracy.Then,a real-time algorithm for estimating PPP-B2b constant bias by using satellite UDP products to construct BeiDou four-frequency AFIF high-precision observations is proposed,and the improvement of PPP-B2b single epoch positioning ability is further analyzed.The consistency of the constant bias values estimated by different stations in each arc of the satellite is verified,and the difference between them is about 0.15 ns.The single epoch positioning accuracy in North/East/Up directions can realize 0.1802,0.1355 and 0.5207 m respectively after using the constant bias estimation value to correct.The above experimental solutions show that the constant bias value estimated by the above algorithm can greatly improve the positioning accuracy of PPP-B2b single epoch compared with no correction.The positioning accuracy is similar to the precise ephemeris solutions,and the real-time single epoch decimeter-level positioning of PPP-B2b is realized.