顾及频间钟差的BDS/GPS三频非组合精密单点定位方法

GPS/BDS triple-frequency uncombined precise point positioning taking into account inter frequency clock bias

采用传统精密钟差产品进行多频精密单点定位(PPP)时,频间钟差(IFCB)会对定位结果产生明显的系统性偏差,针对此问题,提出了基于无几何模型的BDS/GPS频间钟差估计方法,并推导了其在三频非组合PPP模型中的应用方法。通过全球184个监测站连续7天的数据实验,验证分析了IFCB的时变特性。结果表明:GPS和BDS GEO/IGSO卫星的IFCB周期性明显,BDS的IFCB量级小于GPS,一般不超过3 cm;对于静态PPP,与不改正IFCB相比,IFCB改正后,单GPS点位精度提高83.4%,GPS和BDS GEO/IGSO/MEO卫星的相位验后残差标准差分别减小了75.0%、54.5%、32.1%和19.2%;对于动态PPP,单GPS和BDS/GPS双系统组合的点位精度分别提高59.6%和54.7%。该方法解决了传统钟差产品与多频精密定位的兼容问题。

When using traditional precise clock products for multi-frequency precise point positioning(PPP),the inter-frequency clock bias(IFCB)will cause significant systematic deviations in the positioning results.Aiming at this problem,the estimation method of BDS/GPS IFCB based on geometry-free is proposed,and its application in tripe-frequency uncombined PPP is derived.An week of observation from 184 multi-GNSS experiment(MGEX)stations is processed to extract IFCB of BDS/GPS,and its variation characteristics with time are analyzed.The results show that the periodicities of IFCB for GPS and BDS GEO/IGSO are obvious,and the magnitude for BDS is rather smaller than that of GPS,generally not more than 3 cm.For static PPP,compared with no IFCB correction,the accuracy of GPS-only is increased by 83.4%after applying IFCB correction,and the standard deviations of phase residuals of GPS and BDS GEO/IGSO/MEO are decreased by 75.0%,54.5%,32.1%and 19.2%,respectively.For kinematic PPP,the positioning accuracies of GPS-only and BDS/GPS dual-system combination is increased by 59.6%and 54.7%,respectively.The proposed method solves the compatibility problem between traditional clock products and multi-frequency precise positioning.