| 摘要: |
| GPS高精度定位技术在动态复杂环境中，其定位精度、可靠性和连续性因卫星信号频繁失锁而变差。为此，提出了采用基于RTS滤波（Rauch-Tung-Striebel Filter）的GPS+BDS非差非组合PPP（Precise Point Positioning）与INS（Inertial Navigation System）紧组合模型的策略来克服GPS在动态定位中的弱点。其中，采用GPS+BDS双系统观测数据，可提高PPP解算中的可用卫星数，改善星站间定位几何强度和提高PPP收敛速度；采用PPP/INS紧组合，利用INS的自主定位特性和短期高精度特性，可有效改善复杂环境下的定位精度和连续性；采用RTS滤波，可进一步提高PPP/INS紧组合性能。首先推导了GPS+BDS非差非组合函数模型、PPP/INS紧组合函数模型和RTS滤波函数模型，然后利用一组车载动态数据，对动态GPS PPP、GPS+BDS PPP、GPS/INS紧组合、GPS+BDS PPP/INS紧组合和基于RTS的GPS+BDS PPP/IMU紧组合的定位、测速和定姿性能进行分析。实验结果表明，该方案可有效提高定位（58%~72%）、测速（74%~82%）和定姿（4%~23%）精度，特别是对卫星失锁期间的定位性能改善尤为明显。 |
| 关键词: 北斗卫星导航系统 非差非组合精密单点定位 惯性导航系统 RTS滤波 |
| DOI： |
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| 基金项目:国家自然科学基金青年基金(41804027)；中央高校基本科研业务费专项资金资助优秀教师基金项目（2652018026） |
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| Mathematical Models of the RTS Filter and Raw GPS+BDS Observation Based PPP/INS Tight Integration |
| CHI Hao-jing,GAO Zhou-zheng,YANG Kai,MIN Yu,CHENG Jia-bei |
| (School of Land Science and Technology, China University of Geosciences, Beijing 100083, China) |
| Abstract: |
| In the dynamic complex environment, the positioning accuracy, reliability and continuity of GPS high-precision positioning technology become worse due to frequent satellite-outages. Therefore, the Rauch-Tung-Striebel (RTS) smoother and GPS+BDS raw observations based precise point positioning (PPP) and inertial navigation system (INS) tight integration mode is proposed to overcome the problems in GPS dynamic applications. Wherein, by using GPS and BDS observations together, more visible satellites, better position dilution of precision (PDOP), and less convergence time of PPP would be obtained. By adopting the PPP/INS tight integration, the characters of active positioning and high-accuracy in short term of INS can be utilized to improve PPP's accuracy and continuity, especially during the satellite-outage periods. The RTS smoother can further improve the performance of PPP/INS tight integration. In this paper, the model of GPS+BDS raw PPP, PPP/INS tight integration, and RTS smoother are introduced. Then, the land-borne vehicle data is used to validate the proposed method performance. The results show that about 58%~72% position accuracy improvements, 74%~82% velocity accuracy improvement, and 4%~23% attitude accuracy enhancements can be obtained by adopting the proposed method. In particular, the positioning performance during the satellite-outages period is improved obviously. |
| Key words: BeiDou Navigation Satellite System (BDS) Raw Precise Point Positioning (PPP) Inertial Navigation System (INS) Rauch-Tung-Striebel filter |
