Maximum likelihood-based range alignment for ISAR imaging

Motion compensation, including range alignment and phase compensation, is the core technique in inverse synthetic aperture radar (ISAR) imaging. In this paper, the maximum likelihood principle is researched for application in range alignment in ISAR imaging. It is proved that under the condition of ignoring the effect of target rotating components, the complex envelope correlating method is maximum likelihood-based range alignment, and this method is optimized by the criterion of the maximum likelihood principle and therefore should be better than other range alignment methods. Moreover, real data processing results in this paper also verify the conclusions described above.