3D ISAR Imaging: ATR Based on the Alignment Between 3D ISAR Reconstruction and CAD Model

Inverse synthetic aperture radar (ISAR) is capable of producing the two-dimensional (2D) and three-dimensional (3D) images of the non-cooperative target. Compared to 2D ISAR images, 3D ISAR reconstruction can provide not only range and cross-range information, but also the height information of the target, which is of great significance for automatic target recognition (ATR). In this paper, a new ATR method based on the alignment between 3D ISAR reconstructions and CAD models of the targets is proposed. First of all, the 3D InISAR reconstructions of the targets are generated by the 3D InISAR imaging technique. Subsequently, the PCA-based method is adopted to obtain the coarse alignment result. In addition, the accurate alignment results are accomplished by the ICP algorithm. Meanwhile, the RMSEs are calculated as a metric to describe the distance between the 3D InISAR reconstructions and the CAD models of the targets. Finally, the ATR can be achieved by choosing the target with the minimum RMSE. The simulation results are provided to verify the validity of the proposed ATR method.