Orbit Determination of an Uncooperative Maneuvering Rso during Proximity Operations

In this study, real-time orbit determination (OD) o f an uncooperative maneuvering resident space object (RSO) using a second satellit e ("Spysat") that is maintaining a close proximity to the RSO is investigated. Spysat execut es pulsed maneuvers to maintain a fixed distance from the RSO while the RSO itself ma y be maneuvering. A novel method to account for maneuver accelerations of the RSO in th e OD filter running onboard Spysat is proposed. Spysat uses onboard relative position sen sors and navigation systems including GPS to measure the orbital states of the RSO. An Ex tended Kalman Filter (EKF) is used as the OD filter to process the measurements and produ ce real-time estimates of the RSO position and velocity. In addition, a variation of the method is presented to allow tracking of a generic maneuvering target from a ground station as well.