Motion-parameter estimation for precession-with-nutation space targets based on wideband radar measurements

Nutation and precession parameter estimation is of great importance for attitude estimation of spin-stabilized space targets. In this paper, we propose a novel method to estimate the nutation and precession parameters of a rigid-body object from the one-dimensional high-resolution radial-range measurements. First, we elaborately derive the kinematic equations and one-dimensional radial-projection model of the precession-with-nutation object, where fixed-point and slipping scatterers are separately taken into account. Second, by using the radial-range trajectories of multiple scatterers, we employ the factorization-based algorithm to obtain the motion reconstruction. Third, we estimate the nutation and precession parameters based on the reconstructed motion and the spectrum analysis of the associated trajectories. Moreover, the l1-norm-based one-dimensional trajectory-recovering technique is developed to deal with the incomplete radial-range trajectories caused by the shadowing effect, specularity, and so on. Finally, experiments are carried out on the electromagnetic analysis data to verify the proposed model and parameter-estimation method.