Study on airborne ISAR imaging of ship targets

Inverse Synthetic Aperture Radar (ISAR) is used to image noncooperative moving targets such as aircrafts, ships and celestial objects. The target rotation relative to the radar is the source for obtaining cross-range resolution in ISAR imaging. In airborne ISAR imaging of ships, the composition of the relative motion is more complicated than in other cases. One component is produced by the relative movement between the radar and the target. The other comes from the ship sway (roll, pitch and yaw). Furthermore, the practical sea-state changes frequently, and is also unpredictable. All of these increase the difficulty in image formation. In this paper, the airborne ISAR imaging of ship targets is substantially discussed, and we design a simulation software kit applicable to practical sea-state and arbitrary flight path. By using the simulated data, the effects of the various relative rotations between the radar and the target on the ISAR image are clearly demonstrated, and this simulation work provides good experiences for further study. Finally, some imaging results under certain simulation conditions are presented