Super-Resolution Sparse Aperture ISAR Imaging of Maneuvering Target via the RELAX Algorithm

A novel super-resolution sparse aperture inverse synthetic aperture radar (SA-ISAR) imaging algorithm with relaxation (RELAX) technique is proposed. First, the motion compensation by the minimum entropy for range alignment (MERA) and the minimum entropy for phase adjustment (MEPA) is employed. Then, the received echo in one range cell is characterized as a multi-component linear frequency-modulated (LFM) signal model, and the RELAX method is adopted successfully to acquire the estimated parameters of it with random sparsely recorded samples. Finally, by the range-instantaneous-Doppler (RID) technique, the super-resolution SA-ISAR images of maneuvering target can be generated consequently. Through the experimental results of raw and simulated data, we validate that the presented SA-ISAR imaging algorithm with the RELAX technique can be efficiently utilized to obtain super-resolution images of maneuvering target.