中文摘要：

我国卫星导航系统IGSO卫星采用动态偏航与零偏航两种姿态控制模式,在太阳矢量与轨道面夹角较小时,采用零偏航。卫星姿态控制模式的切换造成了卫星所受光压力的变化。当处理包含动偏/零偏切换点的数据弧段时,由于卫星精密轨道确定策略及光压模型的不适应,无法用一组光压参数拟合两种状态,造成定轨精度下降。本文提出了利用分段线性模型描述太阳光压的定轨策略,可将定轨重叠弧段URE精度提高75%。解算的光压参数能够反映出两种状态的差异,是解决姿态转换期间轨道确定的有效方法。

英文摘要：

The IGSO satellites in China＇s navigation system have two attitude control modes： Yawsteering 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 statuses are incompatible with one group of solar radiation pressure parameters while processing data arc segments containing both yaw-steering and orbitnormal 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.