基于虚拟观测值的伪距差分方法研究

Research on pseudorange difference method based on virtual observations

针对当前伪距差分服务观测值双差模式基准站坐标涉密不能在线传输与伪距改正数模式标准格式无法兼容北斗卫星导航系统(BDS)的问题,本文基于局域连续运行参考站(CORS)网数据,生成虚拟格网综合伪距改正数,并进一步生成虚拟伪距观测值,向用户实时播发虚拟观测值与站点坐标,用于用户差分定位.实验证明,虚拟格网伪距观测值差分可为用户提供平面亚米级、垂直优于1.5m的定位服务.对实验数据进行分析,给出了格网差分最优配置方案.本文方法在解决上述两个问题的基础上由于服务端计算压力恒定,不受用户数限制,从算法上解决了大量用户并发接入服务的问题.

Aiming at the problem that the coordinates of the base station of double-difference mode of pseudo-range differential service observation cannot be transmitted on-line and the standard format of pseudo-range correction mode can not be compatible with BeiDou,based on the data of local area CORS network,this paper generates the comprehensive pseudo-range correction number of virtual grid,and further generates the virtual pseudo-range observation value,which can broadcast the pseudo-range to users in real time.Quasi-observed values and station coordinates are used for user differential positioning.Experiments show that virtual grid pseudo-distance difference can provide users with planar submeter-level and vertical positioning services superior to 1.5 m.By analyzing the experimental data,the optimal configuration scheme of grid difference is given.On the basis of solving the above two problems,this method solves the problem of a large number of concurrent users accessing the service algorithmally due to the constant calculation pressure of the server and no limitation of the number of users.