Only feature point line-of-sight relative navigation in asteroid exploration descent stage

A new and real-time only feature point light-of-sight (LOS) relative navigation (OFPLOSRN) technology based on only onboard navigation camera (ONC) is proposed for probe approaching mission in asteroid exploration descent stage. In this new method, its real-time can be guaranteed via using only ONC sensor, and it avoids the errors of relative attitude transition matrix determination in the measurement modeling because the angles of unit feature point LOS vectors are only chosen as the measurements and these angles keep invariable in different coordinate frames. The observability of OFPLOSRN is verified by Lie-Differentiation. The numerical simulation results of simulating HAYABUSA landing mission indicate that the relative position, velocity and attitude of probe to feature region in asteroid exploration descent stage can be estimated by the new OFPLOSRN method with sufficient accuracies.