提高地月转移轨道入轨段初轨精度的技术途径

针对星箭分离前、后两段数据处于不同的飞行轨道,经典的轨道计算方法无法实现两段外测数据联合参与定轨,入轨段初轨精度难以进一步提高的问题,通过分析星箭分离时刻轨道半长轴确定精度与测量误差、轨道偏心率之间的关系,提出了提高站址坐标测量精度、采用分布式船姿船位测量体制以提高姿态测量精度、采用卫星测高数据计算任务海域垂线偏差并对船姿数据进行修正、船载雷达测速数据的东平台影响修正、合理的数据预处理以及采用基于速度增量修正的定轨新方法等多种技术途径,并重点介绍了基于速度增量修正、可实现星箭分离前后外测数据联合定轨的新方法。仿真计算和任务实测数据验算表明,新方法轨道半长轴确定精度较以往传统方法提高1个数量级以上,有利于后续测控计划制定和测控站的跟踪引导。

Technical approaches for improving accuracy of initial orbit determination in injection phase of earth-moon transfer trajectory

In the injection phase where two segments of measurements are obtained for different trajectories, the classical orbit determination method can not implement a united estimation. It is difficult to further improve the accuracy of the initial orbit determination. The paper improves the position measurement accuracy of tracking stations by analyzing the relation among semi-major axis, tracking errors and orbit eccentricity. A distributed ship position-attitude measurement architecture is adopted to improve the accuracy of ship attitude. The altitude measurements by satellites are used to estimate gravimetric plumb line deflection of the mission area and improve the ship attitude, velocity tracking data obtained by ship-borne radar. Other new methods, such as optimal data preprocessing and injection velocity correction, are also proposed. Numerical results show that the new approaches improve the accuracy over one order of magnitude than the traditional method and will benefit to the tracking plan and guidance of downrange tracking stations.