张小红, 李盼, 左翔. 固定模糊度的精密单点定位几何定轨方法及结果分析[J]. 武汉大学学报 ( 信息科学版), 2013, 38(9): 1009-1013.
引用本文: 张小红, 李盼, 左翔. 固定模糊度的精密单点定位几何定轨方法及结果分析[J]. 武汉大学学报 ( 信息科学版), 2013, 38(9): 1009-1013.
ZHANG Xiaohong, LI Pan, ZUO Xiang. Kinematic Precise Orbit Determination Based on Ambiguity-Fixed PPP[J]. Geomatics and Information Science of Wuhan University, 2013, 38(9): 1009-1013.
Citation: ZHANG Xiaohong, LI Pan, ZUO Xiang. Kinematic Precise Orbit Determination Based on Ambiguity-Fixed PPP[J]. Geomatics and Information Science of Wuhan University, 2013, 38(9): 1009-1013.

固定模糊度的精密单点定位几何定轨方法及结果分析

Kinematic Precise Orbit Determination Based on Ambiguity-Fixed PPP

  • 摘要: 传统的基于PPP(precise point positioning)模式的定轨方法采用浮点解,导致其定轨精度及可靠性较双差固定解稍差。为了进一步提高PPP模式事后定轨的精度和可靠性,利用2012年1月2~7日全球IGS跟踪站数据计算出当天所有卫星的宽巷和窄巷FCB产品,实现了GRACE卫星固定PPP整数模糊度的精密定轨。并将定轨结果分别与GFZ事后精密轨道、K波段测距结果进行比较,分析其内外符合精度。实验结果表明:与GFZ提供的事后精密轨道相比,GRACE-A卫星单天轨道固定解的精度为R方向2~3cm,T方向大部分优于2cm,N方向优于2cm,较之浮点解的定轨结果3个方向分别改善了约19%、30%、50%;GRACE-B卫星3个方向精度分别为2~3cm、2cm左右、1~2cm,较之浮点解各方向也有同等程度的改善。与K波段测距结果相比,浮点解的KBR残差STD均值为22.6mm,固定解为16.4mm,比浮点解提高了约28%。可见,PPP模糊度固定解明显改善了低轨卫星的定轨精度,能提供更可靠的轨道服务。

     

    Abstract: With the development of space-borne GPS technologies and IGS precise orbit and clock products,precise orbit determination(POD) of Low Earth Orbiters(LEOs) based on PPP technology has become a hot issue.At present,an accuracy of 3~5 cm in Radial(R),Along-track(T),Cross-track(N) components can be achieved with conventional PPP.However,the results are less precise or reliable than the double-differenced fixed solution due to the ambiguity-float solution in traditional PPP.In order to further improve the precision and reliability of POD with PPP,daily observations from all IGS tracking stations through day 2 to 7 in 2012 were used to estimate the wide and narrow-lane fractional cycle bias(FCB) of all satellites for PPP integer ambiguity resolution.The POD of the two GRACE satellites were respectively compared with GFZ’s post precise orbit and K-band measurements for the analysis of the inner and external conformities.As compared to GFZ,the daily orbital accuracy of the ambiguity-fixed solution in this work is about 2~3 cm in R direction,better than 2 cm in T direction and better than 2 cm in N direction for GRACE-A,an improvement of 19%,30% and 50% respectively when compared with that of the float solution.The POD precision for GRACE-B are 2-3 cm,2 cm and 1-2 cm in R,N,T directions for the fixed solution,respectively.The accuracy improvement in the fixed solution for GARCE-B is nearly equivalent with that for GRACE-A.For K-band cases,the mean STD error of KBR residual is about 16.4 mm for the fixed solution,and 22.6 mm for the float solution.These results show that PPP with ambiguity-fixed can greatly improve POD precision of LEO satellites and provide more reliable orbital service.

     

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