A slope-based technique for motion estimation and optimum time selection for ISAR imaging of ship targets

The focus of this paper is on optimum time selection and angular motion estimation for ship ISAR imaging. The aim is to select proper imaging intervals and to estimate ship angular motion in order to obtain high quality top-view or side-view ship images suitable for processing by classification/identification procedures. To this purpose a slope-based ISAR algorithm is proposed, able to estimate the time instants better suited for top or side-view image formation and the rotation motion vertical/horizontal components for image scaling. The performance of the proposed ISAR technique is investigated against simulated data under different ship model, ship motion, acquisition geometry and background conditions. Results obtained by applying the proposed technique to live ISAR data proves the effectiveness of the proposed approach.