综合伪距相位观测的北斗导航系统广域差分模型

发布时间：2018-08-22 11:15

【摘要】：我国区域北斗卫星导航系统为用户提供开放服务和授权服务两种服务方式,其中授权服务主要提供一维等效钟差改正数和完好性信息,实现更高精度的服务性能。北斗卫星导航系统提供的实时差分信息是基于CNMC平滑后的伪距观测数据计算,其精度受到残余伪距噪声的限制。为提升系统广域差分服务性能,本文提出了一种广域差分新模型。该模型综合了伪距及相位观测数据,并新增了轨道改正数。模型中经相位平滑的伪距观测值用于定义钟差改正数和轨道改正数的基准,而相位历元间差分观测值用于计算约束差分改正数的高精度相对变化。论文分析了数据采样率、测站个数等因素对新模型的影响,并采用中国区域内的观测站数据对新模型进行精度验证。试验结果表明:(1)基于新广域差分模型的GEO卫星UDRE指标相对原有模型提升了27%,IGSO卫星指标提升了35%,MEO卫星指标提升了24%;(2)基于新的广域差分模型,用户在南北、东西、高程方向的伪距定位精度分别提升了23%、32%和52%,实现了北斗系统用户导航定位三维定位精度优于1m的指标。
[Abstract]:China's regional Beidou satellite navigation system provides both open and authorized services to users, in which authorization services mainly provide one-dimensional equivalent clock error corrections and integrity information to achieve more accurate service performance. The real-time differential information provided by Beidou satellite navigation system is based on the CNMC smoothing pseudo-range observation data. Its accuracy is limited by the residual pseudo-range noise. In order to improve the performance of wide area differential service, a new wide area differential model is proposed in this paper. The model synthesizes pseudo-range and phase observation data and adds orbit correction. In the model, the phase smoothing pseudo-range observations are used to define the datum of clock error correction and orbit correction, while the phase epoch difference observation value is used to calculate the high-precision relative variation of constrained difference correction. In this paper, the influence of data sampling rate and the number of stations on the new model is analyzed, and the accuracy of the new model is verified by the observational data in China. The results show that: (1) compared with the original model, the GEO satellite UDRE index based on the new wide-area differential model has increased by 27%, and the index of the UDRE satellite has increased by 35% and 24%; (2) based on the new wide-area differential model, the users are in the north, south, east and west, The pseudo-range positioning accuracy of elevation direction is improved by 32% and 52% respectively, and the 3D positioning accuracy of Beidou system is better than 1m.
【作者单位】：中国科学院上海天文台;中国科学院大学;北京卫星导航中心;同济大学测量与国土信息工程系;德国地学研究中心;
【基金】：国家自然科学基金(11673050;41674041;11403112) 国家863计划(2014AA123102) 上海市空间导航与定位技术重点实验室基金(ZZTX-201401)~~
【分类号】：P228.4

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