在轨卫星GPS导航实时高精度定轨控制仿真

The Simulation of Real-Time High Precision Orbit Determination Control Based on Space-Borne GPS Navigation

目前越来越多的应用需要依赖高精度的实时卫星轨道数据,由于目前GPS接收机所使用的广播星历精度不高和星上处理器性能有限等原因,实时定轨的精度不是很理想。针对这种情况,提出了一种新的星载GPS实时定轨方法。上述方法采用工程应用背景,使用IGS发布的超快速星历代替广播星历,以相位平滑后的测码伪距作为主要观测量,结合简化的动力学模型,通过扩展卡尔曼滤波器进行低轨卫星轨道的实时解算。为了验证其性能,使用上述算法对CHAMP卫星的在轨实际观测数据进行模拟实时处理,结果表明,改进方法不仅计算量小,而且定轨精度高。

In order to increase the precision of broadcast ephemeris used by the GPS receiver and the capability of on-board CPU, a novel real-time orbit determination method based on Space-borne GPS pseudorange measurements is proposed. This method is based on the engineering background. In this method, the IGS ultra-rapid ephemeris is used to replace the broadcast ephemeris, while the GPS pseudorange measurements which are smooth with the carrier phase are taken as basic observations, and a simplified dynamic model is established when achieving the real-time calculating with the extended Kalman filter. In order to verify the performance of the algorithm, a simulative real- time process related to real measure data of CHAMP is conducted. The result shows that this method has less calcula- tion and higher orbit determination precision than the current GPS receivers.