A Method of Satellite Selection for High Orbiter Navigation Based on Equivalent WDOP

With the development of the Global Navigation Satellite System (GNSS), more visible satellites are available for high orbiting vehicles, which greatly improves the positioning capability of high orbiting vehicles. The traditional Geometric Dilution of Precision (GDOP) metric can only reflect the instantaneous positioning accuracy of standard navigation and positioning services. In order to take the number of satellites, the speed of movement, the level of geometric variation and the differences in satellite navigation signals into consideration, and to reduce the computational effort to alleviate the processing load on high-orbiting vehicles, this article proposes an evaluation index Equivalent WDOP (EWDOP) based on cumulative epochs and weighted accuracy factor depending on the motion characteristics of high orbiting vehicles. The Chaotic Particle Swarm Optimization (CPSO) is used to test the optimization of arc segments composed of multiple epochs for a variety of high orbiting vehicles. The result shows that the accuracy of EWDOP-based arc segment optimization for Geosynchronous Orbit (GEO) is 2%-7% lower compared to GDOP-based single epoch optimization. However, using EWDOP saves approximately 80% of computation time, also providing a more stable satellite configuration based on satellite selection results, and yields more robust positioning results.