Abstract :
High resolution radar provide resolution cell sizes which in range and cross range are 2-3 orders of magnitude lower than the corresponding dimensions of surface ships. Assuming an X-band illumination and a moderate size ship, one will have to use 108-109 surface patches if the characteristic patch dimensions are required to be in the order of one wavelength. If the surface patch sizes are increased or reduced, the required number of surface patches decreases or increases in a quadratic fashion. Accurate modeling of radar scattering from such large targets presents a rather difficult numerical task. The problem can only be addressed via asymptotic techniques and even then the required computation times become excessive when fine details of the scattering phenomena are of interest. We have developed a computationally efficient simulation program, which can effectively be used to generate ISAR images of ships. We introduce several improvements and extensions to our basic model and investigate the feasibility of its use in determining the relative importance´s of the various factors effecting the ISAR signatures of ships and in evaluating the performance of automatic ship classifiers
