在轨卫星GPS导航实时高精度定轨控制仿真

摘要

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 realtime process related to real measure data of CHAMP is conducted.The result shows that this method has less calculation and higher orbit determination precision than the current GPS receivers.%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.