Analysis of Influence of Reasonable Weight Ratio on Single Point Positioning of GPS／BDS Pseudorange

 GPS／BDS combination positioning is a combination of two systems observations for positioning solution, but the GPS system and the Beidou system there is a systematic 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 localization 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 satellites 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