Radon transform and the modified envelope correlation method for ISAR imaging of multi-target

In multi-target ISAR imaging, if the returned signals are range non-separable and the relative radial velocity is large. We can neither resolve them in range domain nor the Doppler frequency domain. In order to solve this problem, the use of the Radon transform and a modified envelope correlation method for multi-target ISAR imaging is presented. The radon transform is used to align the range profiles coarsely. For more accuracy alignment, a modified envelope correlation method is proposed. After range alignment, phase compensation is fulfilled by Discrete chirp-Fourier transform (DCFT). The simulation results show that the method proposed in this paper is effective.