北斗小数周偏差时变特性分析及应用

Analysis and application of time-varying property of BDS fractional cycle bias

小数周偏差可用于精密单点定位的模糊度固定,其时变特性对于FCB的播发间隔、数据总量有着重要影响。当前北斗应用进入成熟期,对北斗FCB时变特性及其变化进行研究,有利于推广北斗PPP模糊度固定应用。本文基于单差FCB的生成方法,对2017年和2019年的北斗FCB时变特性展开研究,并改进了IGSO卫星窄巷FCB的播发间隔,通过已知测站固定解PPP解算,验证了改进后的北斗FCB产品。试验表明:2019年北斗FCB的稳定性相比2017年大幅提高;IGSO卫星可每天播发一组窄巷FCB,相比原有播发间隔减小73.4%的数据总量;改进后FCB可有效应用于北斗固定解PPP,收敛速度相比浮点解提升43.1%。

Fractional cyclebias can be used in ambiguity resolution of precise point positioning. Its time-varying property has an important impact on the broadcast interval and the data amount of FCB. Since the application of BDS has entered a mature stage,studying the time-varying property and its changes of BDS FCB is conducive to promoting the application of BDS PPP ambiguity resolution.Based on the generation method of single-difference FCB,this paper analyzes the time-varying property of the BDS FCB in 2017 and 2019,and improves the broadcasting interval of the narrow-lane FCB of IGSO satellites. The improved FCB is verified by the fixed-solution PPP of known reference stations.Experiments show that the stability of BDS FCB in 2019 is greatly improved compared to2017;IGSO satellites can broadcast one group of narrow-lane FCB for one day,which reduce the data amount by 73.4%;the improved FCB can also be effectively applied to the fixed-solution BDS PPP,the convergence speed of which is 43. 1% faster than the floatsolution PPP.