GPS/BDS组合定位综合利用两系统观测值进行定位解算,但GPS系统与北斗系统间存在着系统差异,为了保证组合定位时两系统间数据合理分配,需确定解算时两系统观测值间合理的权比。本文通过对几组不同先验权比时伪距单点定位结果比较选出的最佳权比与利用Helmert方差分量估计方法求得的两个系统伪距单定位权比进行分析,结果表明,GPS/BDS组合定位时的合理的先验权比为1∶1,但在某些时间段内,其中一个系统的卫星数减少或数据质量不佳等情况时,这会导致该系统观测值在组合定位中的贡献率大大降低,此时就需要分段确定合理权比。
GPS/BDS combination positioning is a combination of two systems observa- tions for positioning solution, but the GPS system and the Beidou system there is a systemat- ic difference. In order to ensure the reasonable allocation of data between the two systems, it is necessary to determine a reasonable weight ratio between the observed values of the two systems. The optimal weight ratio is obtained by using the pseudo-range single-point locali- zation of several different a priori weights ratio and the single-position weight ratio of the two systems obtained by using the Helmert variance component estimation method. The results show that the ratio of GPS/BDS combination is 1 : 1. However, when the number of satel- lites in one system decreases or the data quality is poor, the contribution rate of the system observations in the combined localization is greatly reduced. In this case, it is necessary to determine the reasonable ratio