Modified doppler centroid tracking for ISAR based on image equilibrium

Phase correction is a key step of inverse synthetic aperture radar (ISAR) motion compensation, which seriously affects the ISAR focusing and imaging quality. As a typical phase correction method, Doppler centroid tracking (DCT) method has clear principle and small computation amount. However, the performance of DCT is normally unsatisfactory when the target has strong scattering centers. Based on the analysis and comparison of existing methods, the image-domain equilibrium is proposed in this paper to improve the performance of DCT method. By using the simple operators of equilibrium and feedback, the proposed method may dramatically reduce the effect of prominent scattering centers and improve the robustness and the ultimate imaging quality. Finally, the effectiveness of the proposed method is verified via the performance analysis and imaging results of real airplane target.