Performance evaluation of motion compensation methods in ISAR by computer simulation

Three methods of motion compensation are considered: the scatterer point referencing method, the track-the-target centroid method, and the maximum likelihood (ML) image formation and motion compensation method. Computer simulations of imaging an aircraft in straight flight by a ground-based ISAR (inverse synthetic aperture radar) were carried out. The SNR (signal-to-noise ratio) performance, the susceptibility to target scintillation, and the computational complexity of the three methods are evaluated and compared. It is shown that the scatterer point referencing method is simple in computation, but is susceptible to target scintillation. The track-the-target centroid method and the ML method are able to greatly reduce the track loss arising from target scintillation at the cost of a higher computational load. The SNR performance of the track-the-target centroid method is poorer than that of the other two methods. The ML method suffers from the largest computational complexity among the three methods. Nevertheless, the ML method can provide the best SNR performance of the three methods