Navigation Satellites Orbit Determination with the Enhancement of Low Earth Orbit Satellites

Firstly, the influence of the improvement of the BeiDou navigation satellite system(BDS) and GPS satellites visibility using the three low earth orbit (LEO) satellites GRACE-A/B and Fengyun3C (FY3C) is analyzed. Results show that the improvement to BDS medium earth orbit (MEO) satellites is the most significant, with the single coverage increased by 45.7% and quad-coverage increased by 10.7%, which is equivalent to that of GPS satellites. Then, satellite positioning and dilution of precision (SPDOP) is used to analyze the contribution of LEO satellites to enhance the geometry structure in navigation satellite orbit determination. With the enhancement of three LEO satellites, the SPDOP of the BDS geostationary orbit (GEO) satellites, inclined geosynchronous orbit (IGSO)satellites, MEO satellites and GPS satellites are decreased by 49%, 39.8%, 34.9% and 41.2% respectively. The orbit determination experiment based on the observations from seven regional ground observation stations and three LEO satellites are carried out. The results show that one-dimensional root mean square (1D RMS) of GPS satellites orbit is reduced from 14.4 cm to 10.2 cm, improved by 29.1%. The 1D RMS of BDS GEO, IGSO and MEO satellites in overlapping arcs decrease from 359.8 cm to 90.5 cm, 175.6 cm to 52.1 cm, and 90.5 cm to 30.4 cm, improved by 74.8%, 70.3%, and 66% respectively.