摘要
随着IGS实时服务的推广,实时轨道、钟差产品可用于实时PPP;然而,在一些通讯条件差的地方,如偏远山区和广袤的海洋,差分信号的播发与接收仍然是实时PPP的障碍。文中提出一种基于单个GPS/BDS信标台的实时PPP定位方法:基站采用广播星历和无电离层伪距、相位观测值,实时估计耦合轨道、钟误差;单向通讯的方式播发给用户端,减小通讯量,提高用户端的定位性能。经过分别距参考站约200km和300km的流动站进行验证,通过约10~12min收敛,GPS/BDS组合可得到水平优于20cm的定位精度。本案验证了采用广播星历进行实时PPP的可行性,为海洋和偏远地区提供一种高精度定位方法。
With the availability of the IGS real-time service（RTS）,near real-time clock and orbit products are possible for real-time precise point positioning（RT-PPP）.However the real-time broadcast of these products may be still a severe challenge for some areas（e.g.the areas with very weak communication signals covered,such as the remote mountainous or broad water area）.Besides,the latency during the calculation and spread process of the real-time products is also a limitation for the real RT-PPP.This paper proposes an alternative RT-PPP method based on the augmentation of single beacon reference station with GPS＋BDS observations,where the coupling clock bias and orbit errors are estimated together.The advantage that the beacon station can broadcast correction information in one-way mode is used.At the beacon station,the fused corrections（mainly including satellite clock and orbit bias）are generated in real time by using broadcast ephemeris and ionosphere-free carrier and pseudorange observations.Then the generated correction is broadcasted to users for RT-PPP with broadcast ephemeris.The simulated experiments with about 200 km and 300 km distance are carried out.The results indicate that using the proposed method,with GPS＋BDS observations,a reliable convergence is possible with about 10~12 minutes to get the horizontal positioning accuracies better than 20 cm.The contents researched in the paper verify the feasibility of real-time PPP based on broadcast ephemeris,which can provide an alternative strategy for the precise positioning application of oceanic or remote areas.
作者
高成发
赵庆
高旺
GAO Chengfa;ZHAO Qing;GAO Wang(School of Transportation, Southeast University, Nanjing 210096, China)
出处
《测绘工程》
CSCD
2018年第5期1-4,9,共5页
Engineering of Surveying and Mapping
关键词
GPS/BDS
实时精密单点定位
信标台
无电离层
广播星历
GPS/BDS
real-time precise point positioning（RT-PPP）
beacon station
ionosphere-free
broadcast ephemeris
