The impact of orbital errors on the estimation of satellite clock errors and PPP
The impact of orbital errors on the estimation of satellite clock errors and PPP
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轨道误差对卫星钟差和PPP估计的影响
DOI：
10.1016/j.asr.2014.06.012
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发表时间：
2014-10-15
影响因子：
2.6
通讯作者：
Liu, Jingnan
中科院分区：
文献类型：
--
作者：
Lou, Yidong;Zhang, Weixing;Liu, Jingnan
精确的卫星轨道和时钟是提供高精度实时PPP（精密单点定位）服务的关键。然而，通过将预测的轨道视为固定的，轨道误差可能被估计的卫星时钟部分同化，从而影响定位解决方案。本文通过理论研究和实验评估，分析了径向和切向轨道分量误差对卫星钟和PPP估计的影响。详细讨论了卫星钟对轨道误差的补偿与卫星站几何条件的关系。根据不同规模的区域台站网络（半径约为100公里、300公里、500公里和700公里）估算的卫星时钟，结果表明，卫星时钟估算值补偿的轨道误差随着网络规模的增加而减小。提出了一种基于广播星历和相应的卫星时钟估计的区域PPP模式，并通过数值研究进行了评估。广播星历表中的轨道误差的影响对于半径约为300公里的区域网络中的公私伙伴关系用户来说是可以忽略不计的，在飞行任务后运动学模式中，东、北和上部分的定位RMS约为1.4、1.4和3.7厘米，与使用精确轨道和相应的估计时钟时的1.3、1.3和3.6厘米相当。与DGPS和RTK定位相比，该方法只需要向PPP用户传播估计的卫星时钟。它可以大大减轻通信负担，因此可以是有益的真实的时间的应用。(C)2014年空间研委会。由爱思唯尔有限公司出版。保留所有权利。
Precise satellite orbit and clocks are essential for providing high accuracy real-time PPP (Precise Point Positioning) service. However, by treating the predicted orbits as fixed, the orbital errors may be partially assimilated by the estimated satellite clock and hence impact the positioning solutions. This paper presents the impact analysis of errors in radial and tangential orbital components on the estimation of satellite clocks and PPP through theoretical study and experimental evaluation. The relationship between the compensation of the orbital errors by the satellite clocks and the satellite-station geometry is discussed in details. Based on the satellite clocks estimated with regional station networks of different sizes (similar to 100, similar to 300, similar to 500 and similar to 700 km in radius), results indicated that the orbital errors compensated by the satellite clock estimates reduce as the size of the network increases. An interesting regional PPP mode based on the broadcast ephemeris and the corresponding estimated satellite clocks is proposed and evaluated through the numerical study. The impact of orbital errors in the broadcast ephemeris has shown to be negligible for PPP users in a regional network of a radius of similar to 300 km, with positioning RMS of about 1.4, 1.4 and 3.7 cm for east, north and up component in the post-mission kinematic mode, comparable with 1.3, 1.3 and 3.6 cm using the precise orbits and the corresponding estimated clocks. Compared with the DGPS and RTK positioning, only the estimated satellite clocks are needed to be disseminated to PPP users for this approach. It can significantly alleviate the communication burdens and therefore can be beneficial to the real time applications. (C) 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.