Autofocusing of inverse synthetic aperture radar images using contrast optimization

A number of autofocusing techniques are proposed for motion compensation in inverse synthetic aperture radar (ISAR) imaging of objects. These techniques are based on the optimization of a contrast function, which represents a measure of the degree of focus of the image. Three novel image contrast functions are defined and the main steps of the autofocusing algorithm are described. A comparison of the behavior of the proposed techniques is performed analyzing some results obtained from simulation of realistic targets.