Isar rotational motion compensation algorithm using polynomial phase transform

When a target is involved in complicated motion, non-uniform rotational motion is produced, and this leads to blurred inverse synthetic aperture radar (ISAR) images. In order to resolve this problem, we propose a new rotational motion compensation (RMC) method. In the proposed method, a polynomial phase signal of a dominant scatterer is estimated through the polynomial phase transform (PPT). Next, a new slow time variable that achieves uniformly sampled radar signal along the aspect angle direction is defined using the estimated polynomial phase signal. We then interpolate the radar signal in terms of the newly defined slow time variable to construct focused ISAR images. In simulations using the point-scatterer aircraft model and radar cross section (RCS) data computed from physical optics (PO), we demonstrated the robustness and effectiveness of our proposed method.