Analysis of Positioning Performance on Combined BDS/GPS/GLONASS

When single satellite navigation system be used for single point positioning, existing following problem: numbers of visible satellite are low and accuracy of positioning is low. This paper studies the model combination of BDS/GPS/GLONASS system of single point positioning, and a scheme of combined weighting is put forward. The characteristic of combined weight-method is that inside of system adopts elevation to determine weight-value, the inter-system adopts Helmert-Variance to determine weight-value. The experimental results show that the number of visible satellite of combination of BDS/GPS/GLONASS system are than any single-system, and the number of satellites are greatly increasing, and significantly improve user-satellite geometry, and greatly improve accuracy of positioning. Positioning performance of combined weighting is superior to the traditional weighting.