Chapter 12 Optimal Satellite Selecting Algorithm in GPS/BDS Navigation System and Its Implementation

摘要

As the Global Navigation Satellite System (GNSS) steps into a new era of multiple constellations, multiple constellations bring opportunities for navigation and positioning services. Under the condition of the existence of multiple constellations, the number of observable satellite number will increase sharply in single epoch. Because of the limitation of computing source, too much redundant information brought by redundant satellites can not greatly improve the accuracy of positioning, however, it may actually increase the computational burden of receiver. Therefore, optimizing the satellite selection algorithm is of great significance. Based on the relations of constellation's geometry and the principle of GDOP, this paper proposed a satellite selection algorithm suitable for multiple constellations. Furthermore, a satellite selection strategy applied to 5-7 satellites is considered. The experimental results show that on the premise of positioning accuracy, the improved satellite selection satellite can significantly reduce the calculation time and has good real-time performance and reliability.