TSAR Imaging of Multiple Targets Based on Adaptive Gaussian Chirplet Decomposition

When multiple moving targets are close in the same radar beam and can not be separated in range, the conventional ISAR imaging motion compensation algorithms can not get clear images. However, these targets have different velocities and directions, so their Doppler histories of returned signals are different. In a short time, these Doppler histories can be treated as approximately linearly changing frequency signals. Based on which this paper proposes a new method of ISAR imaging of multiple targets using a fast refinement adaptive Gaussian chirplet decomposition algorithm. The method can separate different linear changing Doppler returned signals easily and get their parameters directly. After separating the returned signals of all targets, the conventional ISAR motion compensation algorithm can be used to get clear image of each target. The effectiveness of the method is demonstrated by numerical simulations