Projection Matrix Analysis and Distortion Compensation for 3D ISAR Imaging

Three-dimensional (3D) inverse synthetic aperture radar (ISAR) imaging significantly improves the target discriminability. However, in practical scenarios such as high sea states, the complex target maneuvers will introduce severe projective distortions, which significantly degrade the quality of 3D reconstruction. First, this paper analyzes the projective transformation for 3D ISAR imaging in the single-antenna system, and the transformation matrix that maps the3D space to the parametric imaging space can be derived. Then, this paper further investigates the distortion compensation method for top view dominant scenarios to achieve the robust 3D structural recovery. The proposed method estimates the target’s bottom plane structure and then compensates for the shear distortion by solving an optimization problem formulated to minimize the projected area. Finally, the effectiveness of the algorithm is demonstrated through the results of simulation experiments and processing of measured data.