空间飞行器轨道估计与误差分析

The Orbit Estimation and Error Analysis for Spacecraft

卫星探测是当今空间飞行器观测与轨道估计的重要方式.针对空间飞行器轨道估计及卫星无源探测的误差分析等问题,在双星观测条件下,使用样条插值及拟合的方法对包含随机误差和系统误差的初始数据进行光滑处理,然后基于立体几何和逐点交汇的思想建立了运动方程参数模型,采用最小二乘法估计参数,得到了空间飞行器的估计轨道,并使用LMF法进行了系统误差分析.针对单星观测的情况,一方面,认为飞行器轨道上的点共面且均在过地心的平面内,另一方面,通过建立飞行器轨道模版数据库与观测相对比,了解识别是何种飞行器.添加了这些约束和先验信息后,可以得到大致的轨道估计.

Satellite detection is one of the most important ways in spacecraft observation and orbit estimation. The problem of spacecraft orbit estimation and the error analysis based on passive detection is discussed. In the context of double-satellite detection, spline interpolation and fitting method are employed to smooth the initial data, which includes random error and system error. Then, the parameter model of motion equation is built based on solid geometry and point by point intersection. With the use of least square method, the estimated parameter is obtained, which derives the estimated orbit of spacecraft, then LMF method is used in system error analysis. For the case of single-satellite detection, two constraints are proposed. First, all the points on the orbits are coplanar and in a plane across the geocenter; Second, the type of spacecraft is determined by building the spacecraft orbit database and then comparing the observation result with the database. With the above constraints and prior information, the orbit estimation is obtained.