Research on Technique of Single-Satellite Orbit Determination for GEO Satellite of Partial Subsatellite Point

Regional satellite navigation system contains geostationary satellites (GEO) of partial subsatellite point, subsatellite points of these satellites are away from ground tracking network. These satellites are important to improve the geometric dilution of precision (GDOP) for positioning and time service in sevice area. Comparing with geostationary satellite (GEO) of other subsatellite point, ground tracking geometry condition of GEO of partial subsatellite point is worse, precision of orbit determination of this kind of satellites is not stable and easier to be affected by systemic error. In this paper the principle of POD based on time synchronization mode was proposed particularly and thoroughly. Integrative orbit determination of all satellites could provide precise clock offsets of all satellites and all stations, precise orbit determination (POD) were realized using pseudorange data without clock offset. The technique of single-satellite orbit determination could use all stations which participated in integrative orbit determination, ground tracking geometry condition was improved greatly, at the same time, it could achieve integrative solution of systemic error, POD of this kind of GEO was realized, which could get rid of the restriction of satellite laser ranging data (SLR). Precision of orbit determination were analyzed based on four orbit determination strategies, including solving solar radiation pressure parameters, empirical force parameters and common systemic error, solving solar radiation pressure parameters and common systemic error, solving solar radiation pressure parameters, empirical force parameters and fixing up common systemic error, solving solar radiation pressure parameters and fixing up common systemic error. The experiment based on ground data results indicated that precision of orbit determination based on the strategies of solving solar radiation pressure parameters and fixing up common systemic error was highest. The orbit accuracy in radial component was better than 1 m, which was evaluated with SLR data, the 2 h orbital prediction errors were 1 m, the precision was stable, POD of GEO of partial subsatellite point was come true.