ISAR imaging of multiple moving targets based on synthetic time-frequency analysis

Multiple targets imaging is often required in an Inverse Synthetic Aperture Radar (ISAR). When multiple moving targets are close to each other, such as formation of airplanes, the echoes from these targets are overlapped in time. Thus, by utilizing conventional phase compensation algorithm after range alignment, these targets with different radial velocities or maneuvering cannot be clearly imaged. In this paper, we propose an alternative algorithm based on synthetic time-frequency analysis for ISAR imaging of multiple targets. With this method, image blurred problem can be resolved without separating the echo of each target, the targets can be either point or extended, and targets´ motion can be simple or complex. The effectiveness of the proposed method is confirmed by computer simulation.