IGSO Satellite Orbit Determining Strategy Analysis with the Yaw-steering and Orbit normal Attitude Control Mode Switching

The IGSO satellites in China’s navigation system have two attitude control modes:Yaw-steering mode and orbit-normal mode. The orbit-normal mode will be adopted when the acute angle between solar vector and orbit plane is minor. The satellite attitude control modes switching results in significant decrease of the satellite orbit determination accuracy. Switching causes in variations of solar radiation pressure，and therefore the two statures are incompatible with one group of solar radiation pressure parameters while processing data arc segments containing both yaw-steering and orbit normal modes. Hence，this article presents the orbit determination strategy using a piecewise linear model to describe the influences of change in solar radiation pressure，which can enhance 75% orbit overlap accuracy. This change is demonstrated with a resolved solar radiation pressure parameters experiement and is an effective method for orbit determination during the attitude switching.