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An innovative integrated navigation based on norm-constrained UKF during Mars powered descent

An innovative integrated navigation scheme based on norm-constrained Unscented Kalman filter (NCUKF) for the spacecraft attitude quaternion estimation during Mars powered descent is proposed. The norm equality constraints are introduced into the Joseph formula to reconstruct a new constraint cost function of the Unscented Kalman filter. Based on the Miniature Coherent Altimeter and Velocimeter and radio communications between the vehicle and beacons, new measurements are introduced into the navigation systems during Mars powered descent. A numerical simulation has been carried out to estimate the positions, velocities and attitudes of the vehicle, and the performance of the proposed NCUKF is demonstrated.