北斗IGSO/MEO卫星伪距码偏差精化建模方法研究

Modeling BeiDou IGSO and MEO Satellites Code Pseudorange Variations

北斗倾斜地球同步轨道（inclined geosynchronous orbit,IGSO）卫星和中轨（medium earth orbit,MEO）卫星的伪距码观测值存在系统性偏差,针对该偏差的现有建模方法（两步法）包含模糊度消除策略的误差,提出了一种基于历元间差分的一步建模方法,建立了同类型卫星整体的伪距码偏差三次多项式改正模型,并与现有的离散点改正模型进行对比。同时,针对每颗IGSO/MEO卫星的独特性,利用一步法逐卫星建模并评估其改正效果。结果表明,相对于现有的离散点改正模型,精化模型将IGSO/MEO卫星的MelbourneWübbena（MW）值的稳定性平均提高了23.88%,C08卫星的提高幅度最大,约为32.26%。

Variations of code pseudorange observations of BeiDou satellites in inclined geosynchronous orbit（IGSO）and medium earth orbit（MEO）,lead to systematic deviation in code-phase combination observations.The one-step method based on single-difference between epochs,is proposed to modify the above errors,and the corresponding correction model has also been given.It is shown that,comparing with the existing modeling proposed by Wanninger et al,the final optimized models in this paper using one-step method can improve the stability of Melbourne-Wübbena（MW）observables of all IGSO/MEO satellites with the proportion of 23.88%on average.It is worthy to mention that C08 satellite performs the most remarkable improvement with the proportion up to 32.26%.