| Formation flying of multiple spacecrafts is an enabling technology for many future space missions. It allows a few small cost-effective satellites to offer capabilities that are only achievable with a much more expensive single satellite. While spacecraft formation flying provides many operational and performance advantages, it also poses many significant challenges in navigation, guidance, and control. One of the key challenges for a formation flying satellite is to have a very precise and efficient autonomous relative navigation algorithm implemented on a typical computationally restricted on-board computer. This autonomous relative navigation system is a crucial requirement which enables other key components like autonomous guidance and control systems to plan new trajectories and command the satellite movements during any formation keeping or formation reconfiguration maneuvers.;This thesis investigates the autonomous relative navigation problem for formation flying spacecrafts. A highly efficient autonomous relative orbit determination method is developed and numerically evaluated for centralized-controlled close formation flying satellites. In centralized-controlled formation flight, one chief satellite is responsible for simultaneous navigation, guidance and control of all the remaining deputy satellites. The proposed relative orbit determination method employs real-time observation data generated by an active phased array radar and iterated extended Kalman filters to estimate the relative orbit states of all the deputy satellites. |
