Modified sub-integer range alignment based on minimum entropy for ISAR

Inverse synthetic aperture radar (ISAR) has the excellent capacity of generating image of noncooperative target. However, ISAR images are usually degraded due to relative motion between radar and target. In order to improve image quality, motion compensation is indispensable, and range alignment is just the first and key step of translational motion compensation. This paper proposes a sub-integer range alignment method based on minimum entropy, which has high accuracy of range alignment. The simulations are used to test the performance of the proposed method.