Rotation Parameters Estimation and Cross-Range Scaling Research for Range Instantaneous Doppler ISAR Images

The maneuverability of targets cannot be neglected in many circumstances for Inverse Synthetic Aperture Radar (ISAR) imaging procedure. For these circumstances, the Range Instantaneous Doppler (RID) algorithm is required to form the well-focused ISAR images. Simultaneously, as the inevitable means of obtaining the target's cross-range size, the cross-range scaling approach for the RID images also needs to be considered consequently. Since there are few cross-range scaling methods focused on the RID images, we propose a novel method in this paper based on the phase coefficients estimation and scatterers pairing process to solve the problem. Without the special requirements for the scatterers or complicated optimization process, the proposed approach is widely adaptive and efficient. Otherwise, besides the novel estimation method for the rotation parameters, we also propose the novel technique for calculating the cross-range scaling factor of the RID images, which is quite different from that of the Range Doppler (RD) images. Finally, by using the recommended RID imaging algorithm and the proposed cross-range scaling approach, the results of ISAR imaging and cross-range scaling experiments on the simulation and real-data experiment are represented, which demonstrate the effectiveness of the proposed approach in this paper.