A Method of Autonomous Orbit Determination Applied to LEO Satellite

摘要

The observation data which was from spaceborne sensors and earth sensors was conversed appropriately to make the position of the satellite unit vector observation equation for linearized equations, with small amount of calculation and more intuitive physical significance. Through the method of least squares to stimulate the relationship between satellite orbit altitude and geomagnetic field intensity, using magnetometer observation data to obtain geocentric distance. The satellite initial orbit was determined by Lagrange difference algorithm, provide initial value for the filter; One of the key factors that influence the performance of the filter is that two body dynamic orbit model of first-order linear approximation is introduced into the system model. Application of the first derivative of the function value alternative to a linear combination of higher order derivatives of the function value can make the error of differential linearity reduced greatly. In the process of filter designing, apply this method to the state equation linear processing, greatly improved the linear precision of filter state equation. And simulation results show that this kind of low-orbit satellites determination method is effective and feasible.