Total rotational velocity estimation in a multistatic ISAR system

In this study, the authors report on a novel method to estimate the total rotational velocity of a non-cooperative moving target in a multi-static Inverse Synthetic Aperture Radar (ISAR) system. The method requires a system with at least four receivers spatially distributed such that their line-of-sight vectors are not coplanar. By using least squares optimisation, estimates of the magnitude of the effective rotational velocity `seen' by each receiver and trackfile information on the target trajectory and translational velocity are combined to determine the component due purely to the target's own rotational motion; an estimate for the total rotational velocity can thus be obtained, which can be useful for automatic target recognition. The multi-static nature of the system allows the technique to take into account the translational motion component of the total rotational velocity with some levels of robustness, which is not the case with other approaches. Simulated data results demonstrate the feasibility of the proposed method.