天基低轨空间监视雷达密集短弧观测数据的定轨应用研究

当天基雷达采用多波束扫描时，每次与空间目标交会可获取类似跟踪的观测数据。本文讨论了这些密集短弧观测数据在目标轨道改进中的应用。在没有测量时，采用矩阵Ricatti方程计算状态误差；引入观测数据时，比较了EKF和UKF两种滤波算法的轨道改进效果。仿真表明，UKF的收敛速度优于EKF；天基短弧观测数据可以很好地抑制误差发散，满足监视任务需求。

Short-arc Dense Observations in Low Earth Orbit Determination from Space-based Radar

The space-based radar （SBR） will take the tracking alike short-arc dense observations with multi-beams when applied in low Earth orbit surveillance. And the orbit determination can be done with these short-arc dense measurements. The covariance matrix differential equation is integrated along with the state vector between the measurement updates. And the performance of the Extended Kalman Filter （EKF） is compared with the Unscented Kalman Filter （UKF） when the measurements are used. The simulation shows that UKF converges quicker than EKF. And the space-based observations can suppress the error divergence efficiently and keep the high accuracy of the orbit determination to meet the need of surveillance.